Sync with pokered

42 files changed, 1252 insertions, 2611 deletions

diff --git a/engine/overworld/advance_player_sprite.asm b/engine/overworld/advance_player_sprite.asm
index 6b4a0cbb..4ebdac84 100644
--- a/engine/overworld/advance_player_sprite.asm
+++ b/engine/overworld/advance_player_sprite.asm
@@ -1,241 +1,244 @@
 _AdvancePlayerSprite::
-	ld a,[wSpriteStateData1 + 3] ; delta Y
-	ld b,a
-	ld a,[wSpriteStateData1 + 5] ; delta X
-	ld c,a
-	ld hl,wWalkCounter ; walking animation counter
+	ld a, [wSpritePlayerStateData1YStepVector]
+	ld b, a
+	ld a, [wSpritePlayerStateData1XStepVector]
+	ld c, a
+	ld hl, wWalkCounter ; walking animation counter
 	dec [hl]
-	jr nz,.afterUpdateMapCoords
+	jr nz, .afterUpdateMapCoords
 ; if it's the end of the animation, update the player's map coordinates
 	ld hl, wPikachuOverworldStateFlags
 	res 5, [hl]
-	ld a,[wYCoord]
+	ld a, [wYCoord]
 	add b
-	ld [wYCoord],a
-	ld a,[wXCoord]
+	ld [wYCoord], a
+	ld a, [wXCoord]
 	add c
-	ld [wXCoord],a
+	ld [wXCoord], a
 .afterUpdateMapCoords
-	ld a,[wWalkCounter] ; walking animation counter
-	cp a,$07
-	jp nz,.scrollBackgroundAndSprites
+	ld a, [wWalkCounter] ; walking animation counter
+	cp $07
+	jp nz, .scrollBackgroundAndSprites
 ; if this is the first iteration of the animation
-	ld a,c
-	cp a,$01
-	jr nz,.checkIfMovingWest
+	ld a, c
+	cp $01
+	jr nz, .checkIfMovingWest
 ; moving east
-	ld a,[wMapViewVRAMPointer]
-	ld e,a
+	ld a, [wMapViewVRAMPointer]
+	ld e, a
 	and $e0
-	ld d,a
-	ld a,e
+	ld d, a
+	ld a, e
 	add $02
 	and $1f
 	or d
-	ld [wMapViewVRAMPointer],a
+	ld [wMapViewVRAMPointer], a
 	jr .adjustXCoordWithinBlock
 .checkIfMovingWest
-	cp a,$ff
-	jr nz,.checkIfMovingSouth
+	cp $ff
+	jr nz, .checkIfMovingSouth
 ; moving west
-	ld a,[wMapViewVRAMPointer]
-	ld e,a
-	and a,$e0
-	ld d,a
-	ld a,e
+	ld a, [wMapViewVRAMPointer]
+	ld e, a
+	and $e0
+	ld d, a
+	ld a, e
 	sub $02
 	and $1f
 	or d
-	ld [wMapViewVRAMPointer],a
+	ld [wMapViewVRAMPointer], a
 	jr .adjustXCoordWithinBlock
 .checkIfMovingSouth
-	ld a,b
-	cp a,$01
-	jr nz,.checkIfMovingNorth
+	ld a, b
+	cp $01
+	jr nz, .checkIfMovingNorth
 ; moving south
-	ld a,[wMapViewVRAMPointer]
+	ld a, [wMapViewVRAMPointer]
 	add $40
-	ld [wMapViewVRAMPointer],a
-	jr nc,.adjustXCoordWithinBlock
-	ld a,[wMapViewVRAMPointer + 1]
+	ld [wMapViewVRAMPointer], a
+	jr nc, .adjustXCoordWithinBlock
+	ld a, [wMapViewVRAMPointer + 1]
 	inc a
 	and $03
 	or $98
-	ld [wMapViewVRAMPointer + 1],a
+	ld [wMapViewVRAMPointer + 1], a
 	jr .adjustXCoordWithinBlock
 .checkIfMovingNorth
-	cp a,$ff
-	jr nz,.adjustXCoordWithinBlock
+	cp $ff
+	jr nz, .adjustXCoordWithinBlock
 ; moving north
-	ld a,[wMapViewVRAMPointer]
+	ld a, [wMapViewVRAMPointer]
 	sub $40
-	ld [wMapViewVRAMPointer],a
-	jr nc,.adjustXCoordWithinBlock
-	ld a,[wMapViewVRAMPointer + 1]
+	ld [wMapViewVRAMPointer], a
+	jr nc, .adjustXCoordWithinBlock
+	ld a, [wMapViewVRAMPointer + 1]
 	dec a
 	and $03
 	or $98
-	ld [wMapViewVRAMPointer + 1],a
+	ld [wMapViewVRAMPointer + 1], a
 .adjustXCoordWithinBlock
-	ld a,c
+	ld a, c
 	and a
-	jr z,.pointlessJump ; mistake?
+	jr z, .pointlessJump ; mistake?
 .pointlessJump
-	ld hl,wXBlockCoord
-	ld a,[hl]
+	ld hl, wXBlockCoord
+	ld a, [hl]
 	add c
-	ld [hl],a
+	ld [hl], a
 	cp $02
-	jr nz,.checkForMoveToWestBlock
+	jr nz, .checkForMoveToWestBlock
 ; moved into the tile block to the east
 	xor a
-	ld [hl],a
-	ld hl,wXOffsetSinceLastSpecialWarp
+	ld [hl], a
+	ld hl, wXOffsetSinceLastSpecialWarp
 	inc [hl]
-	ld de,wCurrentTileBlockMapViewPointer
+	ld de, wCurrentTileBlockMapViewPointer
 	call MoveTileBlockMapPointerEast
 	jr .updateMapView
 .checkForMoveToWestBlock
-	cp a,$ff
-	jr nz,.adjustYCoordWithinBlock
+	cp $ff
+	jr nz, .adjustYCoordWithinBlock
 ; moved into the tile block to the west
-	ld a,$1
-	ld [hl],a
-	ld hl,wXOffsetSinceLastSpecialWarp
+	ld a, $01
+	ld [hl], a
+	ld hl, wXOffsetSinceLastSpecialWarp
 	dec [hl]
-	ld de,wCurrentTileBlockMapViewPointer
+	ld de, wCurrentTileBlockMapViewPointer
 	call MoveTileBlockMapPointerWest
 	jr .updateMapView
 .adjustYCoordWithinBlock
-	ld hl,wYBlockCoord
-	ld a,[hl]
+	ld hl, wYBlockCoord
+	ld a, [hl]
 	add b
-	ld [hl],a
-	cp $2
-	jr nz,.checkForMoveToNorthBlock
+	ld [hl], a
+	cp $02
+	jr nz, .checkForMoveToNorthBlock
 ; moved into the tile block to the south
 	xor a
-	ld [hl],a
-	ld hl,wYOffsetSinceLastSpecialWarp
+	ld [hl], a
+	ld hl, wYOffsetSinceLastSpecialWarp
 	inc [hl]
-	ld de,wCurrentTileBlockMapViewPointer
-	ld a,[wCurMapWidth]
+	ld de, wCurrentTileBlockMapViewPointer
+	ld a, [wCurMapWidth]
 	call MoveTileBlockMapPointerSouth
 	jr .updateMapView
 .checkForMoveToNorthBlock
-	cp a,$ff
-	jr nz,.updateMapView
+	cp $ff
+	jr nz, .updateMapView
 ; moved into the tile block to the north
-	ld a,$1
-	ld [hl],a
-	ld hl,wYOffsetSinceLastSpecialWarp
+	ld a, $01
+	ld [hl], a
+	ld hl, wYOffsetSinceLastSpecialWarp
 	dec [hl]
-	ld de,wCurrentTileBlockMapViewPointer
-	ld a,[wCurMapWidth]
+	ld de, wCurrentTileBlockMapViewPointer
+	ld a, [wCurMapWidth]
 	call MoveTileBlockMapPointerNorth
 .updateMapView
 	call LoadCurrentMapView
-	ld a,[wSpriteStateData1 + 3] ; delta Y
-	cp $1
-	jr nz,.checkIfMovingNorth2
+	ld a, [wSpritePlayerStateData1YStepVector]
+	cp $01
+	jr nz, .checkIfMovingNorth2
 ; if moving south
 	call ScheduleSouthRowRedraw
 	jr .scrollBackgroundAndSprites
 .checkIfMovingNorth2
 	cp $ff
-	jr nz,.checkIfMovingEast2
+	jr nz, .checkIfMovingEast2
 ; if moving north
 	call ScheduleNorthRowRedraw
 	jr .scrollBackgroundAndSprites
 .checkIfMovingEast2
-	ld a,[wSpriteStateData1 + 5] ; delta X
-	cp $1
-	jr nz,.checkIfMovingWest2
+	ld a, [wSpritePlayerStateData1XStepVector]
+	cp $01
+	jr nz, .checkIfMovingWest2
 ; if moving east
 	call ScheduleEastColumnRedraw
 	jr .scrollBackgroundAndSprites
 .checkIfMovingWest2
 	cp $ff
-	jr nz,.scrollBackgroundAndSprites
+	jr nz, .scrollBackgroundAndSprites
 ; if moving west
 	call ScheduleWestColumnRedraw
 .scrollBackgroundAndSprites
-	ld a,[wSpriteStateData1 + 3] ; delta Y
+	ld a, [wSpritePlayerStateData1YStepVector]
 	add a
-	ld b,a
-	ld a,[wSpriteStateData1 + 5] ; delta X
+	ld b, a
+	ld a, [wSpritePlayerStateData1XStepVector]
 	add a
-	ld c,a
+	ld c, a
 ; shift all the sprites in the direction opposite of the player's motion
 ; so that the player appears to move relative to them
-	ld hl,wSpriteStateData1 + $14
-	ld e,15
+	ld hl, wSprite01StateData1YPixels
+	ld e, 15
 .spriteShiftLoop
-	ld a,[hl]
+	ld a, [hl]
 	sub b
-	ld [hli],a
+	ld [hli], a
 	inc l
-	ld a,[hl]
+	ld a, [hl]
 	sub c
-	ld [hl],a
-	ld a,$0e
+	ld [hl], a
+	ld a, $0e
 	add l
-	ld l,a
+	ld l, a
 	dec e
-	jr nz,.spriteShiftLoop
+	jr nz, .spriteShiftLoop
 .done
-	ld a,[hSCY]
+	ldh a, [hSCY]
 	add b
-	ld [hSCY],a ; update background scroll Y
-	ld a,[hSCX]
+	ldh [hSCY], a ; update background scroll Y
+	ldh a, [hSCX]
 	add c
-	ld [hSCX],a ; update background scroll X
+	ldh [hSCX], a ; update background scroll X
 	ret
 
+; the following four functions are used to move the pointer to the upper left
+; corner of the tile block map in the direction of motion
+
 MoveTileBlockMapPointerEast::
-	ld a,[de]
-	add $1
-	ld [de],a
+	ld a, [de]
+	add $01
+	ld [de], a
 	ret nc
 	inc de
-	ld a,[de]
+	ld a, [de]
 	inc a
-	ld [de],a
+	ld [de], a
 	ret
 
 MoveTileBlockMapPointerWest::
-	ld a,[de]
-	sub $1
-	ld [de],a
+	ld a, [de]
+	sub $01
+	ld [de], a
 	ret nc
 	inc de
-	ld a,[de]
+	ld a, [de]
 	dec a
-	ld [de],a
+	ld [de], a
 	ret
 
 MoveTileBlockMapPointerSouth::
-	add $6
-	ld b,a
-	ld a,[de]
+	add MAP_BORDER * 2
+	ld b, a
+	ld a, [de]
 	add b
-	ld [de],a
+	ld [de], a
 	ret nc
 	inc de
-	ld a,[de]
+	ld a, [de]
 	inc a
-	ld [de],a
+	ld [de], a
 	ret
 
 MoveTileBlockMapPointerNorth::
-	add $6
-	ld b,a
-	ld a,[de]
+	add MAP_BORDER * 2
+	ld b, a
+	ld a, [de]
 	sub b
-	ld [de],a
+	ld [de], a
 	ret nc
 	inc de
-	ld a,[de]
+	ld a, [de]
 	dec a
-	ld [de],a
+	ld [de], a
 	ret
diff --git a/engine/overworld/npc_movement.asm b/engine/overworld/auto_movement.asm
index 670cb121..a68da55f 100755
--- a/engine/overworld/npc_movement.asm
+++ b/engine/overworld/auto_movement.asm
@@ -1,4 +1,4 @@
-PlayerStepOutFromDoor:
+PlayerStepOutFromDoor::
 	ld hl, wd730
 	res 1, [hl]
 	call IsPlayerStandingOnDoorTile
@@ -12,7 +12,7 @@ PlayerStepOutFromDoor:
 	ld a, D_DOWN
 	ld [wSimulatedJoypadStatesEnd], a
 	xor a
-	ld [wSpriteStateData1 + 2], a
+	ld [wSpritePlayerStateData1ImageIndex], a
 	call StartSimulatingJoypadStates
 	ret
 .notStandingOnDoor
@@ -27,7 +27,7 @@ PlayerStepOutFromDoor:
 	res 7, [hl]
 	ret
 
-_EndNPCMovementScript:
+_EndNPCMovementScript::
 	ld hl, wd730
 	res 7, [hl]
 	ld hl, wd72e
@@ -44,7 +44,7 @@ _EndNPCMovementScript:
 	ld [wSimulatedJoypadStatesEnd], a
 	ret
 
-PalletMovementScriptPointerTable:
+PalletMovementScriptPointerTable::
 	dw PalletMovementScript_OakMoveLeft
 	dw PalletMovementScript_PlayerMoveLeft
 	dw PalletMovementScript_WaitAndWalkToLab
@@ -66,7 +66,7 @@ PalletMovementScript_OakMoveLeft:
 	call FillMemory
 	ld [hl], $ff
 	ld a, [wSpriteIndex]
-	ld [H_SPRITEINDEX], a
+	ldh [hSpriteIndex], a
 	ld de, wNPCMovementDirections2
 	call MoveSprite
 	ld a, $1
@@ -95,7 +95,7 @@ PalletMovementScript_PlayerMoveLeft:
 	ret nz ; return if Oak is still moving
 	ld a, [wNumStepsToTake]
 	ld [wSimulatedJoypadStatesIndex], a
-	ld [hNPCMovementDirections2Index], a
+	ldh [hNPCMovementDirections2Index], a
 	predef ConvertNPCMovementDirectionsToJoypadMasks
 	call StartSimulatingJoypadStates
 	ld a, $2
@@ -114,7 +114,7 @@ PalletMovementScript_WalkToLab:
 	swap a
 	ld [wNPCMovementScriptSpriteOffset], a
 	xor a
-	ld [wSpriteStateData2 + $06], a
+	ld [wSpritePlayerStateData2MovementByte1], a
 	ld hl, wSimulatedJoypadStatesEnd
 	ld de, RLEList_PlayerWalkToLab
 	call DecodeRLEList
@@ -133,21 +133,21 @@ PalletMovementScript_WalkToLab:
 
 
 RLEList_ProfOakWalkToLab:
-	db NPC_MOVEMENT_DOWN, $06 ; differs from red
-	db NPC_MOVEMENT_LEFT, $01
-	db NPC_MOVEMENT_DOWN, $05
-	db NPC_MOVEMENT_RIGHT, $03
-	db NPC_MOVEMENT_UP, $01
-	db $E0, $01 ; stand still
-	db $FF
+	db NPC_MOVEMENT_DOWN, 6 ; differs from red
+	db NPC_MOVEMENT_LEFT, 1
+	db NPC_MOVEMENT_DOWN, 5
+	db NPC_MOVEMENT_RIGHT, 3
+	db NPC_MOVEMENT_UP, 1
+	db NPC_CHANGE_FACING, 1
+	db -1 ; end
 
 RLEList_PlayerWalkToLab:
-	db D_UP, $02
-	db D_RIGHT, $03
-	db D_DOWN, $05
-	db D_LEFT, $01
-	db D_DOWN, $07 ; differs from red
-	db $FF
+	db D_UP, 2
+	db D_RIGHT, 3
+	db D_DOWN, 5
+	db D_LEFT, 1
+	db D_DOWN, 7 ; differs from red
+	db -1 ; end
 
 PalletMovementScript_Done:
 	ld a, [wSimulatedJoypadStatesIndex]
@@ -162,7 +162,7 @@ PalletMovementScript_Done:
 	res 7, [hl]
 	jp EndNPCMovementScript
 
-PewterMuseumGuyMovementScriptPointerTable:
+PewterMuseumGuyMovementScriptPointerTable::
 	dw PewterMovementScript_WalkToMuseum
 	dw PewterMovementScript_Done
 
@@ -193,18 +193,18 @@ PewterMovementScript_WalkToMuseum:
 	ret
 
 RLEList_PewterMuseumPlayer:
-	db 0, $01
-	db D_UP, $03
-	db D_LEFT, $0D
-	db D_UP, $06
-	db $FF
+	db NO_INPUT, 1
+	db D_UP, 3
+	db D_LEFT, 13
+	db D_UP, 6
+	db -1 ; end
 
 RLEList_PewterMuseumGuy:
-	db NPC_MOVEMENT_UP, $06
-	db NPC_MOVEMENT_LEFT, $0D
-	db NPC_MOVEMENT_UP, $03
-	db NPC_MOVEMENT_LEFT, $01
-	db $FF
+	db NPC_MOVEMENT_UP, 6
+	db NPC_MOVEMENT_LEFT, 13
+	db NPC_MOVEMENT_UP, 3
+	db NPC_MOVEMENT_LEFT, 1
+	db -1 ; end
 
 PewterMovementScript_Done:
 	ld a, [wSimulatedJoypadStatesIndex]
@@ -216,7 +216,7 @@ PewterMovementScript_Done:
 	res 7, [hl]
 	jp EndNPCMovementScript
 
-PewterGymGuyMovementScriptPointerTable:
+PewterGymGuyMovementScriptPointerTable::
 	dw PewterMovementScript_WalkToGym
 	dw PewterMovementScript_Done
 
@@ -229,7 +229,7 @@ PewterMovementScript_WalkToGym:
 	swap a
 	ld [wNPCMovementScriptSpriteOffset], a
 	xor a
-	ld [wSpriteStateData2 + $06], a
+	ld [wSpritePlayerStateData2MovementByte1], a
 	ld hl, wSimulatedJoypadStatesEnd
 	ld de, RLEList_PewterGymPlayer
 	call DecodeRLEList
@@ -250,21 +250,21 @@ PewterMovementScript_WalkToGym:
 	ret
 
 RLEList_PewterGymPlayer:
-	db 0, $01
-	db D_RIGHT, $02
-	db D_DOWN, $05
-	db D_LEFT, $0B
-	db D_UP, $05
-	db D_LEFT, $0F
-	db $FF
+	db NO_INPUT, 1
+	db D_RIGHT, 2
+	db D_DOWN, 5
+	db D_LEFT, 11
+	db D_UP, 5
+	db D_LEFT, 15
+	db -1 ; end
 
 RLEList_PewterGymGuy:
-	db NPC_MOVEMENT_DOWN, $02
-	db NPC_MOVEMENT_LEFT, $0F
-	db NPC_MOVEMENT_UP, $05
-	db NPC_MOVEMENT_LEFT, $0B
-	db NPC_MOVEMENT_DOWN, $05
-	db NPC_MOVEMENT_RIGHT, $03
-	db $FF
+	db NPC_MOVEMENT_DOWN, 2
+	db NPC_MOVEMENT_LEFT, 15
+	db NPC_MOVEMENT_UP, 5
+	db NPC_MOVEMENT_LEFT, 11
+	db NPC_MOVEMENT_DOWN, 5
+	db NPC_MOVEMENT_RIGHT, 3
+	db -1 ; end
 
-INCLUDE "engine/overworld/pewter_guys.asm"
+INCLUDE "engine/events/pewter_guys.asm"
diff --git a/engine/overworld/cable_club_npc.asm b/engine/overworld/cable_club_npc.asm
deleted file mode 100755
index 12ce64a4..00000000
--- a/engine/overworld/cable_club_npc.asm
+++ /dev/null
@@ -1,208 +0,0 @@
-CableClubNPC:
-	ld hl, CableClubNPCWelcomeText
-	call PrintText
-	call CheckPikachuFollowingPlayer
-	jr nz, .asm_7048
-	CheckEvent EVENT_GOT_POKEDEX
-	jp nz, .receivedPokedex
-; if the player hasn't received the pokedex
-.asm_7048
-	ld c, 60
-	call DelayFrames
-	ld hl, CableClubNPCMakingPreparationsText
-	call PrintText
-	jp .didNotConnect
-.receivedPokedex
-	ld a, $1
-	ld [wMenuJoypadPollCount], a
-	ld a, 90
-	ld [wLinkTimeoutCounter], a
-.establishConnectionLoop
-	ld a, [hSerialConnectionStatus]
-	cp USING_INTERNAL_CLOCK
-	jr z, .establishedConnection
-	cp USING_EXTERNAL_CLOCK
-	jr z, .establishedConnection
-	ld a, CONNECTION_NOT_ESTABLISHED
-	ld [hSerialConnectionStatus], a
-	ld a, ESTABLISH_CONNECTION_WITH_EXTERNAL_CLOCK
-	ld [rSB], a
-	xor a
-	ld [hSerialReceiveData], a
-	ld a, START_TRANSFER_EXTERNAL_CLOCK
-	ld [rSC], a
-	ld a, [wLinkTimeoutCounter]
-	dec a
-	ld [wLinkTimeoutCounter], a
-	jr z, .failedToEstablishConnection
-	ld a, ESTABLISH_CONNECTION_WITH_INTERNAL_CLOCK
-	ld [rSB], a
-	ld a, START_TRANSFER_INTERNAL_CLOCK
-	ld [rSC], a
-	call DelayFrame
-	jr .establishConnectionLoop
-.establishedConnection
-	call Serial_SendZeroByte
-	call DelayFrame
-	call Serial_SendZeroByte
-	ld c, 50
-	call DelayFrames
-	ld hl, CableClubNPCPleaseApplyHereHaveToSaveText
-	call PrintText
-	xor a
-	ld [wMenuJoypadPollCount], a
-	call YesNoChoice
-	ld a, $1
-	ld [wMenuJoypadPollCount], a
-	ld a, [wCurrentMenuItem]
-	and a
-	jr nz, .choseNo
-	callab SaveSAVtoSRAM
-	call WaitForSoundToFinish
-	ld a, SFX_SAVE
-	call PlaySoundWaitForCurrent
-	ld hl, CableClubNPCPleaseWaitText
-	call PrintText
-	ld hl, wUnknownSerialCounter
-	ld a, $3
-	ld [hli], a
-	xor a
-	ld [hl], a
-	ld [hSerialReceivedNewData], a
-	ld [wSerialExchangeNybbleSendData], a
-	call Serial_SyncAndExchangeNybble
-	ld hl, wUnknownSerialCounter
-	ld a, [hli]
-	inc a
-	jr nz, .connected
-	ld a, [hl]
-	inc a
-	jr nz, .connected
-	ld b, 10
-.syncLoop
-	call DelayFrame
-	call Serial_SendZeroByte
-	dec b
-	jr nz, .syncLoop
-	call CloseLinkConnection
-	ld hl, CableClubNPCLinkClosedBecauseOfInactivityText
-	call PrintText
-	jr .didNotConnect
-.failedToEstablishConnection
-	ld hl, CableClubNPCAreaReservedFor2FriendsLinkedByCableText
-	call PrintText
-	jr .didNotConnect
-.choseNo
-	call CloseLinkConnection
-	ld hl, CableClubNPCPleaseComeAgainText
-	call PrintText
-.didNotConnect
-	xor a
-	ld hl, wUnknownSerialCounter
-	ld [hli], a
-	ld [hl], a
-	ld hl, wd72e
-	res 6, [hl]
-	xor a
-	ld [wMenuJoypadPollCount], a
-	ret
-.connected
-	xor a
-	ld [hld], a
-	ld [hl], a
-	ld a, [wLetterPrintingDelayFlags]
-	push af
-	callab LinkMenu
-	pop af
-	ld [wLetterPrintingDelayFlags], a
-	ret
-
-; seems to be similar of Serial_SyncAndExchangeNybble
-Serial_SyncAndExchangeNybbleDouble:
-	ld a, $ff
-	ld [wSerialExchangeNybbleReceiveData], a
-.loop
-	call Serial_ExchangeNybble
-	call DelayFrame
-	push hl
-	ld hl, wUnknownSerialCounter + 1
-	dec [hl]
-	jr nz, .next
-	dec hl
-	dec [hl]
-	jr nz, .next
-	pop hl
-	jr .setUnknownSerialCounterToFFFF
-.next
-	pop hl
-	ld a, [wSerialExchangeNybbleReceiveData]
-	inc a
-	jr z, .loop
-	call DelayFrame
-	ld a, $ff
-	ld [wSerialExchangeNybbleReceiveData], a
-	call Serial_ExchangeNybble
-	ld a, [wSerialExchangeNybbleReceiveData]
-	inc a
-	jr z, .loop
-	ld b, 10
-.syncLoop1
-	call DelayFrame
-	call Serial_ExchangeNybble
-	dec b
-	jr nz, .syncLoop1
-	ld b, 10
-.syncLoop2
-	call DelayFrame
-	call Serial_SendZeroByte
-	dec b
-	jr nz, .syncLoop2
-	ld a, [wSerialExchangeNybbleReceiveData]
-	ld [wSerialSyncAndExchangeNybbleReceiveData], a
-	ret
-.setUnknownSerialCounterToFFFF
-	ld a, $ff
-	ld [wUnknownSerialCounter], a
-	ld [wUnknownSerialCounter + 1], a
-	ret
-
-CableClubNPCAreaReservedFor2FriendsLinkedByCableText:
-	TX_FAR _CableClubNPCAreaReservedFor2FriendsLinkedByCableText
-	db "@"
-
-CableClubNPCWelcomeText:
-	TX_FAR _CableClubNPCWelcomeText
-	db "@"
-
-CableClubNPCPleaseApplyHereHaveToSaveText:
-	TX_FAR _CableClubNPCPleaseApplyHereHaveToSaveText
-	db "@"
-
-CableClubNPCPleaseWaitText:
-	TX_FAR _CableClubNPCPleaseWaitText
-	TX_DELAY
-	db "@"
-
-CableClubNPCLinkClosedBecauseOfInactivityText:
-	TX_FAR _CableClubNPCLinkClosedBecauseOfInactivityText
-	db "@"
-
-CableClubNPCPleaseComeAgainText:
-	TX_FAR _CableClubNPCPleaseComeAgainText
-	db "@"
-
-CableClubNPCMakingPreparationsText:
-	TX_FAR _CableClubNPCMakingPreparationsText
-	db "@"
-
-CloseLinkConnection:
-	call Delay3
-	ld a, CONNECTION_NOT_ESTABLISHED
-	ld [hSerialConnectionStatus], a
-	ld a, ESTABLISH_CONNECTION_WITH_EXTERNAL_CLOCK
-	ld [rSB], a
-	xor a
-	ld [hSerialReceiveData], a
-	ld a, START_TRANSFER_EXTERNAL_CLOCK
-	ld [rSC], a
-	ret
diff --git a/engine/overworld/card_key.asm b/engine/overworld/card_key.asm
deleted file mode 100755
index a4452b4a..00000000
--- a/engine/overworld/card_key.asm
+++ /dev/null
@@ -1,113 +0,0 @@
-PrintCardKeyText:
-	ld hl, SilphCoMapList
-	ld a, [wCurMap]
-	ld b, a
-.silphCoMapListLoop
-	ld a, [hli]
-	cp $ff
-	ret z
-	cp b
-	jr nz, .silphCoMapListLoop
-; does not check for tile in front of player. This might be buggy
-	;predef GetTileAndCoordsInFrontOfPlayer
-	ld a, [wTileInFrontOfPlayer]
-	cp $18
-	jr z, .cardKeyDoorInFrontOfPlayer
-	cp $24
-	jr z, .cardKeyDoorInFrontOfPlayer
-	ld b, a
-	ld a, [wCurMap]
-	cp SILPH_CO_11F
-	ret nz
-	ld a, b
-	cp $5e
-	ret nz
-.cardKeyDoorInFrontOfPlayer
-	ld b, CARD_KEY
-	call IsItemInBag
-	jr z, .noCardKey
-	xor a
-	ld [wPlayerMovingDirection], a
-	tx_pre_id CardKeySuccessText
-	ld [hSpriteIndexOrTextID], a
-	call PrintPredefTextID
-	call GetCoordsInFrontOfPlayer
-	srl d
-	ld a, d
-	ld b, a
-	ld [wCardKeyDoorY], a
-	srl e
-	ld a, e
-	ld c, a
-	ld [wCardKeyDoorX], a
-	ld a, [wCurMap]
-	cp SILPH_CO_11F
-	jr nz, .notSilphCo11F
-	ld a, $3
-	jr .replaceCardKeyDoorTileBlock
-.notSilphCo11F
-	ld a, $e
-.replaceCardKeyDoorTileBlock
-	ld [wNewTileBlockID], a
-	predef ReplaceTileBlock
-	ld hl, wCurrentMapScriptFlags
-	set 5, [hl]
-	ld a, SFX_GO_INSIDE
-	jp PlaySound
-.noCardKey
-	tx_pre_id CardKeyFailText
-	ld [hSpriteIndexOrTextID], a
-	jp PrintPredefTextID
-
-SilphCoMapList:
-	db SILPH_CO_2F
-	db SILPH_CO_3F
-	db SILPH_CO_4F
-	db SILPH_CO_5F
-	db SILPH_CO_6F
-	db SILPH_CO_7F
-	db SILPH_CO_8F
-	db SILPH_CO_9F
-	db SILPH_CO_10F
-	db SILPH_CO_11F
-	db $FF
-
-CardKeySuccessText:
-	TX_FAR _CardKeySuccessText1
-	TX_SFX_ITEM_1
-	TX_FAR _CardKeySuccessText2
-	db "@"
-
-CardKeyFailText:
-	TX_FAR _CardKeyFailText
-	db "@"
-
-; d = Y
-; e = X
-GetCoordsInFrontOfPlayer:
-	ld a, [wYCoord]
-	ld d, a
-	ld a, [wXCoord]
-	ld e, a
-	ld a, [wSpritePlayerStateData1FacingDirection] ; player's sprite facing direction
-	and a
-	jr nz, .notFacingDown
-; facing down
-	inc d
-	ret
-.notFacingDown
-	cp SPRITE_FACING_UP
-	jr nz, .notFacingUp
-; facing up
-	dec d
-	ret
-.notFacingUp
-	cp SPRITE_FACING_LEFT
-	jr nz, .notFacingLeft
-; facing left
-	dec e
-	ret
-.notFacingLeft
-; facing right
-	inc e
-	ret
diff --git a/engine/overworld/cinnabar_lab.asm b/engine/overworld/cinnabar_lab.asm
deleted file mode 100755
index 13313746..00000000
--- a/engine/overworld/cinnabar_lab.asm
+++ /dev/null
@@ -1,123 +0,0 @@
-GiveFossilToCinnabarLab:
-	ld hl, wd730
-	set 6, [hl]
-	xor a
-	ld [wCurrentMenuItem], a
-	ld a, A_BUTTON | B_BUTTON
-	ld [wMenuWatchedKeys], a
-	ld a, [wFilteredBagItemsCount]
-	dec a
-	ld [wMaxMenuItem], a
-	ld a, 2
-	ld [wTopMenuItemY], a
-	ld a, 1
-	ld [wTopMenuItemX], a
-	ld a, [wFilteredBagItemsCount]
-	dec a
-	ld bc, 2
-	ld hl, 3
-	call AddNTimes
-	dec l
-	ld b, l
-	ld c, $d
-	coord hl, 0, 0
-	call TextBoxBorder
-	call UpdateSprites
-	call PrintFossilsInBag
-	ld hl, wd730
-	res 6, [hl]
-	call HandleMenuInput
-	bit 1, a ; pressed B?
-	jr nz, .cancelledGivingFossil
-	ld hl, wFilteredBagItems
-	ld a, [wCurrentMenuItem]
-	ld d, 0
-	ld e, a
-	add hl, de
-	ld a, [hl]
-	ld [$ffdb], a
-	cp DOME_FOSSIL
-	jr z, .choseDomeFossil
-	cp HELIX_FOSSIL
-	jr z, .choseHelixFossil
-	ld b, AERODACTYL
-	jr .fossilSelected
-.choseHelixFossil
-	ld b, OMANYTE
-	jr .fossilSelected
-.choseDomeFossil
-	ld b, KABUTO
-.fossilSelected
-	ld [wFossilItem], a
-	ld a, b
-	ld [wFossilMon], a
-	call LoadFossilItemAndMonName
-	ld hl, LabFossil_610ae
-	call PrintText
-	call YesNoChoice
-	ld a, [wCurrentMenuItem]
-	and a
-	jr nz, .cancelledGivingFossil
-	ld hl, LabFossil_610b3
-	call PrintText
-	ld a, [wFossilItem]
-	ld [hItemToRemoveID], a
-	callba RemoveItemByID
-	ld hl, LabFossil_610b8
-	call PrintText
-	SetEvents EVENT_GAVE_FOSSIL_TO_LAB, EVENT_LAB_STILL_REVIVING_FOSSIL
-	ret
-.cancelledGivingFossil
-	ld hl, LabFossil_610bd
-	call PrintText
-	ret
-
-LabFossil_610ae:
-	TX_FAR _Lab4Text_610ae
-	db "@"
-
-LabFossil_610b3:
-	TX_FAR _Lab4Text_610b3
-	db "@"
-
-LabFossil_610b8:
-	TX_FAR _Lab4Text_610b8
-	db "@"
-
-LabFossil_610bd:
-	TX_FAR _Lab4Text_610bd
-	db "@"
-
-PrintFossilsInBag:
-; Prints each fossil in the player's bag on a separate line in the menu.
-	ld hl, wFilteredBagItems
-	xor a
-	ld [hItemCounter], a
-.loop
-	ld a, [hli]
-	cp $ff
-	ret z
-	push hl
-	ld [wd11e], a
-	call GetItemName
-	coord hl, 2, 2
-	ld a, [hItemCounter]
-	ld bc, SCREEN_WIDTH * 2
-	call AddNTimes
-	ld de, wcd6d
-	call PlaceString
-	ld hl, hItemCounter
-	inc [hl]
-	pop hl
-	jr .loop
-
-; loads the names of the fossil item and the resulting mon
-LoadFossilItemAndMonName:
-	ld a, [wFossilMon]
-	ld [wd11e], a
-	call GetMonName
-	call CopyStringToCF4B
-	ld a, [wFossilItem]
-	ld [wd11e], a
-	call GetItemName
-	ret
diff --git a/engine/overworld/clear_variables.asm b/engine/overworld/clear_variables.asm
index 9a59cc7c..bbb7c986 100644
--- a/engine/overworld/clear_variables.asm
+++ b/engine/overworld/clear_variables.asm
@@ -1,14 +1,14 @@
-ClearVariablesOnEnterMap:
-	ld a, SCREEN_HEIGHT_PIXELS
-	ld [hWY], a
-	ld [rWY], a
+ClearVariablesOnEnterMap::
+	ld a, SCREEN_HEIGHT_PX
+	ldh [hWY], a
+	ldh [rWY], a
 	xor a
-	ld [H_AUTOBGTRANSFERENABLED], a
+	ldh [hAutoBGTransferEnabled], a
 	ld [wStepCounter], a
 	ld [wLoneAttackNo], a
-	ld [hJoyPressed], a
-	ld [hJoyReleased], a
-	ld [hJoyHeld], a
+	ldh [hJoyPressed], a
+	ldh [hJoyReleased], a
+	ldh [hJoyHeld], a
 	ld [wActionResultOrTookBattleTurn], a
 	ld [wUnusedD5A3], a
 	ld hl, wCardKeyDoorY
diff --git a/engine/overworld/cut.asm b/engine/overworld/cut.asm
index bc7d092d..e36b8d88 100755
--- a/engine/overworld/cut.asm
+++ b/engine/overworld/cut.asm
@@ -22,8 +22,8 @@ UsedCut:
 	jp PrintText
 
 .NothingToCutText
-	TX_FAR _NothingToCutText
-	db "@"
+	text_far _NothingToCutText
+	text_end
 
 .canCut
 	ld [wCutTile], a
@@ -37,15 +37,15 @@ UsedCut:
 	call GBPalWhiteOutWithDelay3
 	call ClearSprites
 	call RestoreScreenTilesAndReloadTilePatterns
-	ld a, SCREEN_HEIGHT_PIXELS
-	ld [hWY], a
+	ld a, SCREEN_HEIGHT_PX
+	ldh [hWY], a
 	call Delay3
 	call LoadGBPal
 	call LoadCurrentMapView
 	call SaveScreenTilesToBuffer2
 	call Delay3
 	xor a
-	ld [hWY], a
+	ldh [hWY], a
 	ld hl, UsedCutText
 	call PrintText
 	call LoadScreenTilesFromBuffer2
@@ -57,47 +57,47 @@ UsedCut:
 	ld de, CutTreeBlockSwaps
 	call ReplaceTreeTileBlock
 	call RedrawMapView
-	callba AnimCut
+	farcall AnimCut
 	ld a, $1
 	ld [wUpdateSpritesEnabled], a
 	ld a, SFX_CUT
 	call PlaySound
 	ld a, $90
-	ld [hWY], a
+	ldh [hWY], a
 	call UpdateSprites
 	jp RedrawMapView
 
 UsedCutText:
-	TX_FAR _UsedCutText
-	db "@"
+	text_far _UsedCutText
+	text_end
 
 InitCutAnimOAM:
 	xor a
 	ld [wWhichAnimationOffsets], a
 	ld a, %11100100
-	ld [rOBP1], a
+	ldh [rOBP1], a
 	call UpdateGBCPal_OBP1
 	ld a, [wCutTile]
 	cp $52
 	jr z, .grass
 ; tree
-	ld de, Overworld_GFX + $2d0 ; cuttable tree sprite top row
-	ld hl, vChars1 + $7c0
-	lb bc, BANK(Overworld_GFX), $02
+	ld de, Overworld_GFX tile $2d ; cuttable tree sprite top row
+	ld hl, vChars1 tile $7c
+	lb bc, BANK(Overworld_GFX), 2
 	call CopyVideoData
-	ld de, Overworld_GFX + $3d0 ; cuttable tree sprite bottom row
-	ld hl, vChars1 + $7e0
-	lb bc, BANK(Overworld_GFX), $02
+	ld de, Overworld_GFX tile $3d ; cuttable tree sprite bottom row
+	ld hl, vChars1 tile $7e
+	lb bc, BANK(Overworld_GFX), 2
 	call CopyVideoData
 	jr WriteCutOrBoulderDustAnimationOAMBlock
 .grass
-	ld hl, vChars1 + $7c0
+	ld hl, vChars1 tile $7c
 	call LoadCutGrassAnimationTilePattern
-	ld hl, vChars1 + $7d0
+	ld hl, vChars1 tile $7d
 	call LoadCutGrassAnimationTilePattern
-	ld hl, vChars1 + $7e0
+	ld hl, vChars1 tile $7e
 	call LoadCutGrassAnimationTilePattern
-	ld hl, vChars1 + $7f0
+	ld hl, vChars1 tile $7f
 	call LoadCutGrassAnimationTilePattern
 	call WriteCutOrBoulderDustAnimationOAMBlock
 	ld hl, wOAMBuffer + $93
@@ -113,8 +113,8 @@ InitCutAnimOAM:
 	ret
 
 LoadCutGrassAnimationTilePattern:
-	ld de, AnimationTileset2 + $60 ; tile depicting a leaf
-	lb bc, BANK(AnimationTileset2), $01
+	ld de, AnimationTileset2 tile 6 ; tile depicting a leaf
+	lb bc, BANK(AnimationTileset2), 1
 	jp CopyVideoData
 
 WriteCutOrBoulderDustAnimationOAMBlock:
@@ -124,11 +124,11 @@ WriteCutOrBoulderDustAnimationOAMBlock:
 	jp WriteOAMBlock
 
 CutOrBoulderDustAnimationTilesAndAttributes:
-	db $FC,$14,$FD,$14
-	db $FE,$14,$FF,$14
+	dbsprite  2, -1,  4,  4, $fd, OAM_OBP1 | %100
+	dbsprite  2, -1,  4,  6, $ff, OAM_OBP1 | %100
 
 GetCutOrBoulderDustAnimationOffsets:
-	ld hl, wSpriteStateData1 + 4
+	ld hl, wSpritePlayerStateData1YPixels
 	ld a, [hli] ; player's sprite screen Y position
 	ld b, a
 	inc hl
@@ -188,7 +188,7 @@ ReplaceTreeTileBlock:
 	ld h, [hl]
 	ld l, a
 	add hl, bc
-	ld a, [wSpritePlayerStateData1FacingDirection] ; player sprite's facing direction
+	ld a, [wSpritePlayerStateData1FacingDirection]
 	and a
 	jr z, .down
 	cp SPRITE_FACING_UP
@@ -249,16 +249,4 @@ ReplaceTreeTileBlock:
 	ld [hl], a
 	ret
 
-CutTreeBlockSwaps:
-; first byte = tileset block containing the cut tree
-; second byte = corresponding tileset block after the cut animation happens
-	db $32, $6D
-	db $33, $6C
-	db $34, $6F
-	db $35, $4C
-	db $60, $6E
-	db $0B, $0A
-	db $3C, $35
-	db $3F, $35
-	db $3D, $36
-	db $FF ; list terminator
+INCLUDE "data/tilesets/cut_tree_blocks.asm"
diff --git a/engine/overworld/cut2.asm b/engine/overworld/cut2.asm
index 37490f95..1f691eef 100755
--- a/engine/overworld/cut2.asm
+++ b/engine/overworld/cut2.asm
@@ -15,9 +15,9 @@ AnimCut:
 	ld [wCoordAdjustmentAmount], a
 	ld c, 2
 	call AdjustOAMBlockXPos2
-	ld a, [rOBP1]
+	ldh a, [rOBP1]
 	xor $64
-	ld [rOBP1], a
+	ldh [rOBP1], a
 	call UpdateGBCPal_OBP1
 	call DelayFrame
 	pop bc
@@ -66,9 +66,9 @@ AnimCutGrass_UpdateOAMEntries:
 	ld [wCoordAdjustmentAmount], a
 	ld c, 1
 	call AdjustOAMBlockXPos2
-	ld a, [rOBP1]
+	ldh a, [rOBP1]
 	xor $64
-	ld [rOBP1], a
+	ldh [rOBP1], a
 	call UpdateGBCPal_OBP1
 	call DelayFrame
 	pop bc
diff --git a/engine/overworld/doors.asm b/engine/overworld/doors.asm
index 8bde8600..d38818fa 100755
--- a/engine/overworld/doors.asm
+++ b/engine/overworld/doors.asm
@@ -11,7 +11,7 @@ IsPlayerStandingOnDoorTile:
 	ld a, [hli]
 	ld h, [hl]
 	ld l, a
-	aCoord 8, 9 ; a = lower left background tile under player's sprite
+	lda_coord 8, 9 ; a = lower left background tile under player's sprite
 	ld b, a
 .loop
 	ld a, [hli]
@@ -25,55 +25,4 @@ IsPlayerStandingOnDoorTile:
 	and a
 	ret
 
-DoorTileIDPointers:
-	dbw OVERWORLD,   OverworldDoorTileIDs
-	dbw FOREST,      ForestDoorTileIDs
-	dbw MART,        MartDoorTileIDs
-	dbw HOUSE,       HouseDoorTileIDs
-	dbw FOREST_GATE, TilesetMuseumDoorTileIDs
-	dbw MUSEUM,      TilesetMuseumDoorTileIDs
-	dbw GATE,        TilesetMuseumDoorTileIDs
-	dbw SHIP,        ShipDoorTileIDs
-	dbw LOBBY,       LobbyDoorTileIDs
-	dbw MANSION,     MansionDoorTileIDs
-	dbw LAB,         LabDoorTileIDs
-	dbw FACILITY,    FacilityDoorTileIDs
-	dbw PLATEAU,     PlateauDoorTileIDs
-	dbw INTERIOR,    InteriorDoorTileIDs
-	db $ff
-
-OverworldDoorTileIDs:
-	db $1B,$58,$00
-
-ForestDoorTileIDs:
-	db $3a,$00
-
-MartDoorTileIDs:
-	db $5e,$00
-
-HouseDoorTileIDs:
-	db $54,$00
-
-TilesetMuseumDoorTileIDs:
-	db $3b,$00
-
-ShipDoorTileIDs:
-	db $1e,$00
-
-LobbyDoorTileIDs:
-	db $1c,$38,$1a,$00
-
-MansionDoorTileIDs:
-	db $1a,$1c,$53,$00
-
-LabDoorTileIDs:
-	db $34,$00
-
-FacilityDoorTileIDs:
-	db $43,$58,$1b,$00
-
-PlateauDoorTileIDs:
-	db $3b,$1b,$00
-
-InteriorDoorTileIDs:
-	db $04,$15,$00
+INCLUDE "data/tilesets/door_tile_ids.asm"
diff --git a/engine/overworld/dungeon_warps.asm b/engine/overworld/dungeon_warps.asm
index f47dfb01..7641c688 100644
--- a/engine/overworld/dungeon_warps.asm
+++ b/engine/overworld/dungeon_warps.asm
@@ -1,4 +1,4 @@
-IsPlayerOnDungeonWarp:
+IsPlayerOnDungeonWarp::
 	xor a
 	ld [wWhichDungeonWarp], a
 	ld a, [wd72d]
diff --git a/engine/overworld/ssanne.asm b/engine/overworld/dust_smoke.asm
index cf3b1284..773def96 100755
--- a/engine/overworld/ssanne.asm
+++ b/engine/overworld/dust_smoke.asm
@@ -6,10 +6,10 @@ AnimateBoulderDust:
 	ld a, $ff
 	ld [wUpdateSpritesEnabled], a
 	ld a, %11100100
-	ld [rOBP1], a
+	ldh [rOBP1], a
 	call UpdateGBCPal_OBP1
 	call LoadSmokeTileFourTimes
-	callba WriteCutOrBoulderDustAnimationOAMBlock
+	farcall WriteCutOrBoulderDustAnimationOAMBlock
 	ld c, 8 ; number of steps in animation
 .loop
 	push bc
@@ -19,9 +19,9 @@ AnimateBoulderDust:
 	ld c, 4
 	jp hl
 .returnAddress
-	ld a, [rOBP1]
+	ldh a, [rOBP1]
 	xor %01100100
-	ld [rOBP1], a
+	ldh [rOBP1], a
 	call UpdateGBCPal_OBP1
 	call Delay3
 	pop bc
@@ -32,7 +32,7 @@ AnimateBoulderDust:
 	jp LoadPlayerSpriteGraphics
 
 GetMoveBoulderDustFunctionPointer:
-	ld a, [wSpritePlayerStateData1FacingDirection] ; player's sprite facing direction
+	ld a, [wSpritePlayerStateData1FacingDirection]
 	ld hl, MoveBoulderDustFunctionPointerTable
 	ld c, a
 	ld b, $0
@@ -70,15 +70,15 @@ MoveBoulderDustFunctionPointerTable:
 	db $FF,$01
 	dw AdjustOAMBlockXPos
 
-LoadSmokeTileFourTimes:
-	ld hl, vChars1 + $7c0
-	ld c, $4
+LoadSmokeTileFourTimes::
+	ld hl, vChars1 tile $7c
+	ld c, 4
 .loop
 	push bc
 	push hl
 	call LoadSmokeTile
 	pop hl
-	ld bc, $10
+	ld bc, 1 tiles
 	add hl, bc
 	pop bc
 	dec c
@@ -91,5 +91,5 @@ LoadSmokeTile:
 	jp CopyVideoData
 
 SSAnneSmokePuffTile:
-	INCBIN "gfx/ss_anne_smoke_puff.2bpp"
+	INCBIN "gfx/overworld/smoke.2bpp"
 SSAnneSmokePuffTileEnd:
diff --git a/engine/overworld/elevator.asm b/engine/overworld/elevator.asm
index 47ec78f9..b873ffad 100755
--- a/engine/overworld/elevator.asm
+++ b/engine/overworld/elevator.asm
@@ -1,11 +1,11 @@
-ShakeElevator:
+ShakeElevator::
 	ld de, -$20
 	call ShakeElevatorRedrawRow
 	ld de, SCREEN_HEIGHT * $20
 	call ShakeElevatorRedrawRow
 	call Delay3
 	call StopAllMusic
-	ld a, [hSCY]
+	ldh a, [hSCY]
 	ld d, a
 	ld e, $1
 	ld b, 100
@@ -14,7 +14,7 @@ ShakeElevator:
 	xor $fe
 	ld e, a
 	add d
-	ld [hSCY], a
+	ldh [hSCY], a
 	push bc
 	ld c, BANK(SFX_Collision_1)
 	ld a, SFX_COLLISION
@@ -25,7 +25,7 @@ ShakeElevator:
 	dec b
 	jr nz, .shakeLoop
 	ld a, d
-	ld [hSCY], a
+	ldh [hSCY], a
 	call StopAllMusic
 	ld c, BANK(SFX_Safari_Zone_PA)
 	ld a, SFX_SAFARI_ZONE_PA
@@ -54,7 +54,7 @@ ShakeElevatorRedrawRow:
 	add hl, de
 	ld a, h
 	and $3
-	or vBGMap0 / $100
+	or HIGH(vBGMap0)
 	ld d, a
 	ld a, l
 	pop hl
diff --git a/engine/overworld/emotion_bubbles.asm b/engine/overworld/emotion_bubbles.asm
index 3b02fd55..3ad714e9 100755
--- a/engine/overworld/emotion_bubbles.asm
+++ b/engine/overworld/emotion_bubbles.asm
@@ -11,8 +11,8 @@ EmotionBubble:
 	add hl, bc
 	ld e, l
 	ld d, h
-	ld hl, vChars1 + $780
-	lb bc, BANK(EmotionBubbles), $04
+	ld hl, vChars1 tile $78
+	lb bc, BANK(EmotionBubbles), 4
 	call CopyVideoData
 	ld a, [wUpdateSpritesEnabled]
 	push af
@@ -41,7 +41,7 @@ EmotionBubble:
 	jr nz, .loop
 
 ; get the screen coordinates of the sprite the bubble is to be displayed above
-	ld hl, wSpriteStateData1 + 4
+	ld hl, wSpritePlayerStateData1YPixels
 	ld a, [wEmotionBubbleSpriteIndex]
 	swap a
 	ld c, a
@@ -67,8 +67,15 @@ EmotionBubble:
 
 
 EmotionBubblesOAM:
-	db $F8,$00,$F9,$00
-	db $FA,$00,$FB,$00
+	dbsprite  0, -1,  0,  0, $f9, 0
+	dbsprite  0, -1,  0,  2, $fb, 0
 
 EmotionBubbles:
-	INCBIN "gfx/emotion_bubbles.2bpp"
+ShockEmote:    INCBIN "gfx/emotes/shock.2bpp"
+QuestionEmote: INCBIN "gfx/emotes/question.2bpp"
+HappyEmote:    INCBIN "gfx/emotes/happy.2bpp"
+SkullEmote:    INCBIN "gfx/emotes/skull.2bpp"
+HeartEmote:    INCBIN "gfx/emotes/heart.2bpp"
+BoltEmote:     INCBIN "gfx/emotes/bolt.2bpp"
+ZzzEmote:      INCBIN "gfx/emotes/zzz.2bpp"
+FishEmote:     INCBIN "gfx/emotes/fish.2bpp"
diff --git a/engine/overworld/field_move_messages.asm b/engine/overworld/field_move_messages.asm
index 1d111917..520ef8ad 100644
--- a/engine/overworld/field_move_messages.asm
+++ b/engine/overworld/field_move_messages.asm
@@ -7,16 +7,16 @@ PrintStrengthTxt:
 	jp PrintText
 
 UsedStrengthText:
-	TX_FAR _UsedStrengthText
-	TX_ASM
+	text_far _UsedStrengthText
+	text_asm
 	ld a, [wcf91]
 	call PlayCry
 	call Delay3
 	jp TextScriptEnd
 
 CanMoveBouldersText:
-	TX_FAR _CanMoveBouldersText
-	db "@"
+	text_far _CanMoveBouldersText
+	text_end
 
 IsSurfingAllowed:
 ; Returns whether surfing is allowed in bit 1 of wd728.
@@ -32,7 +32,7 @@ IsSurfingAllowed:
 	ret nz
 	CheckBothEventsSet EVENT_SEAFOAM4_BOULDER1_DOWN_HOLE, EVENT_SEAFOAM4_BOULDER2_DOWN_HOLE
 	ret z
-	ld hl, CoordsData_f5b64
+	ld hl, CoordsData_cdf7
 	call ArePlayerCoordsInArray
 	ret nc
 	ld hl, wd728
@@ -45,13 +45,14 @@ IsSurfingAllowed:
 	ld hl, CyclingIsFunText
 	jp PrintText
 
-CoordsData_f5b64:
-	db $0B,$07,$FF
+CoordsData_cdf7:
+	dbmapcoord  7, 11
+	db -1 ; end
 
 CurrentTooFastText:
-	TX_FAR _CurrentTooFastText
-	db "@"
+	text_far _CurrentTooFastText
+	text_end
 
 CyclingIsFunText:
-	TX_FAR _CyclingIsFunText
-	db "@"
+	text_far _CyclingIsFunText
+	text_end
diff --git a/engine/overworld/healing_machine.asm b/engine/overworld/healing_machine.asm
index e5ba004e..e5fba7e1 100755
--- a/engine/overworld/healing_machine.asm
+++ b/engine/overworld/healing_machine.asm
@@ -1,17 +1,17 @@
 AnimateHealingMachine:
 	ld de, PokeCenterFlashingMonitorAndHealBall
-	ld hl, vChars0 + $7c0
-	lb bc, BANK(PokeCenterFlashingMonitorAndHealBall), $03 ; loads one too many tiles
+	ld hl, vChars0 tile $7c
+	lb bc, BANK(PokeCenterFlashingMonitorAndHealBall), 3 ; should be 2
 	call CopyVideoData
 	ld hl, wUpdateSpritesEnabled
 	ld a, [hl]
 	push af
 	ld [hl], $ff
 	push hl
-	ld a, [rOBP1]
+	ldh a, [rOBP1]
 	push af
 	ld a, $e0
-	ld [rOBP1], a
+	ldh [rOBP1], a
 	call UpdateGBCPal_OBP1
 	ld hl, wOAMBuffer + $84
 	ld de, PokeCenterOAMData
@@ -53,7 +53,7 @@ AnimateHealingMachine:
 	ld c, 32
 	call DelayFrames
 	pop af
-	ld [rOBP1], a
+	ldh [rOBP1], a
 	call UpdateGBCPal_OBP1
 	pop hl
 	pop af
@@ -61,24 +61,26 @@ AnimateHealingMachine:
 	jp UpdateSprites
 
 PokeCenterFlashingMonitorAndHealBall:
-	INCBIN "gfx/pokecenter_ball.2bpp"
+	INCBIN "gfx/overworld/heal_machine.2bpp"
 
 PokeCenterOAMData:
-	db $24,$34,$7C,$14 ; heal machine monitor
-	db $2B,$30,$7D,$14 ; pokeballs 1-6
-	db $2B,$38,$7D,$34
-	db $30,$30,$7D,$14
-	db $30,$38,$7D,$34
-	db $35,$30,$7D,$14
-	db $35,$38,$7D,$34
+	; heal machine monitor
+	dbsprite  6,  4,  4,  4, $7c, OAM_OBP1 | %100
+	; poke balls 1-6
+	dbsprite  6,  5,  0,  3, $7d, OAM_OBP1 | %100
+	dbsprite  7,  5,  0,  3, $7d, OAM_OBP1 | OAM_HFLIP | %100
+	dbsprite  6,  6,  0,  0, $7d, OAM_OBP1 | %100
+	dbsprite  7,  6,  0,  0, $7d, OAM_OBP1 | OAM_HFLIP | %100
+	dbsprite  6,  6,  0,  5, $7d, OAM_OBP1 | %100
+	dbsprite  7,  6,  0,  5, $7d, OAM_OBP1 | OAM_HFLIP | %100
 
 ; d = value to xor with palette
 FlashSprite8Times:
 	ld b, 8
 .loop
-	ld a, [rOBP1]
+	ldh a, [rOBP1]
 	xor d
-	ld [rOBP1], a
+	ldh [rOBP1], a
 	call UpdateGBCPal_OBP1
 	ld c, 10
 	call DelayFrames
@@ -88,16 +90,9 @@ FlashSprite8Times:
 
 CopyHealingMachineOAM:
 ; copy one OAM entry and advance the pointers
+	REPT 4
 	ld a, [de]
 	inc de
 	ld [hli], a
-	ld a, [de]
-	inc de
-	ld [hli], a
-	ld a, [de]
-	inc de
-	ld [hli], a
-	ld a, [de]
-	inc de
-	ld [hli], a
+	ENDR
 	ret
diff --git a/engine/overworld/hidden_items.asm b/engine/overworld/hidden_items.asm
deleted file mode 100755
index b64411c7..00000000
--- a/engine/overworld/hidden_items.asm
+++ /dev/null
@@ -1,172 +0,0 @@
-HiddenItems:
-	ld hl, HiddenItemCoords
-	call FindHiddenItemOrCoinsIndex
-	ld [wHiddenItemOrCoinsIndex], a
-	ld hl, wObtainedHiddenItemsFlags
-	ld a, [wHiddenItemOrCoinsIndex]
-	ld c, a
-	ld b, FLAG_TEST
-	predef FlagActionPredef
-	ld a, c
-	and a
-	jr nz, .itemAlreadyFound
-	call EnableAutoTextBoxDrawing
-	ld a, 1
-	ld [wDoNotWaitForButtonPressAfterDisplayingText], a
-	ld a, [wHiddenObjectFunctionArgument] ; item ID
-	ld [wd11e], a
-	call GetItemName
-	tx_pre_jump FoundHiddenItemText
-
-.itemAlreadyFound
-	ld a, $ff
-	ld [hItemAlreadyFound], a
-	ret
-
-INCLUDE "data/hidden_item_coords.asm"
-
-FoundHiddenItemText:
-	TX_FAR _FoundHiddenItemText
-	TX_ASM
-	ld a, [wHiddenObjectFunctionArgument] ; item ID
-	ld b, a
-	ld c, 1
-	call GiveItem
-	jr nc, .bagFull
-	ld hl, wObtainedHiddenItemsFlags
-	ld a, [wHiddenItemOrCoinsIndex]
-	ld c, a
-	ld b, FLAG_SET
-	predef FlagActionPredef
-	ld a, SFX_GET_ITEM_2
-	call PlaySoundWaitForCurrent
-	call WaitForSoundToFinish
-	jp TextScriptEnd
-.bagFull
-	call WaitForTextScrollButtonPress ; wait for button press
-	xor a
-	ld [wDoNotWaitForButtonPressAfterDisplayingText], a
-	ld hl, HiddenItemBagFullText
-	call PrintText
-	jp TextScriptEnd
-
-HiddenItemBagFullText:
-	TX_FAR _HiddenItemBagFullText
-	db "@"
-
-HiddenCoins:
-	ld b, COIN_CASE
-	predef GetQuantityOfItemInBag
-	ld a, b
-	and a
-	jr z, .doNotPickUpCoins
-	ld hl, HiddenCoinCoords
-	call FindHiddenItemOrCoinsIndex
-	ld [wHiddenItemOrCoinsIndex], a
-	ld hl, wObtainedHiddenCoinsFlags
-	ld a, [wHiddenItemOrCoinsIndex]
-	ld c, a
-	ld b, FLAG_TEST
-	predef FlagActionPredef
-	ld a, c
-	and a
-	jr nz, .doNotPickUpCoins
-	xor a
-	ld [hUnusedCoinsByte], a
-	ld [hCoins], a
-	ld [hCoins + 1], a
-	ld a, [wHiddenObjectFunctionArgument]
-	sub COIN
-	cp 10
-	jr z, .bcd10
-	cp 20
-	jr z, .bcd20
-	cp 40
-	jr z, .bcd20 ; should be bcd40
-	jr .bcd100
-
-.doNotPickUpCoins
-	ld a, $ff
-	ld [hItemAlreadyFound], a
-	ret
-
-.bcd10
-	ld a, $10
-	ld [hCoins + 1], a
-	jr .bcdDone
-.bcd20
-	ld a, $20
-	ld [hCoins + 1], a
-	jr .bcdDone
-.bcd40 ; due to a typo, this is never used
-	ld a, $40
-	ld [hCoins + 1], a
-	jr .bcdDone
-.bcd100
-	ld a, $1
-	ld [hCoins], a
-.bcdDone
-	ld de, wPlayerCoins + 1
-	ld hl, hCoins + 1
-	ld c, $2
-	predef AddBCDPredef
-	ld hl, wObtainedHiddenCoinsFlags
-	ld a, [wHiddenItemOrCoinsIndex]
-	ld c, a
-	ld b, FLAG_SET
-	predef FlagActionPredef
-	call EnableAutoTextBoxDrawing
-	ld a, [wPlayerCoins]
-	cp $99
-	jr nz, .roomInCoinCase
-	ld a, [wPlayerCoins + 1]
-	cp $99
-	jr nz, .roomInCoinCase
-	tx_pre_id DroppedHiddenCoinsText
-	jr .done
-.roomInCoinCase
-	tx_pre_id FoundHiddenCoinsText
-.done
-	jp PrintPredefTextID
-
-INCLUDE "data/hidden_coins.asm"
-
-FoundHiddenCoinsText:
-	TX_FAR _FoundHiddenCoinsText
-	TX_SFX_ITEM_2
-	db "@"
-
-DroppedHiddenCoinsText:
-	TX_FAR _FoundHiddenCoins2Text
-	TX_SFX_ITEM_2
-	TX_FAR _DroppedHiddenCoinsText
-	db "@"
-
-FindHiddenItemOrCoinsIndex:
-	ld a, [wHiddenObjectY]
-	ld d, a
-	ld a, [wHiddenObjectX]
-	ld e, a
-	ld a, [wCurMap]
-	ld b, a
-	ld c, -1
-.loop
-	inc c
-	ld a, [hli]
-	cp $ff ; end of the list?
-	ret z  ; if so, we're done here
-	cp b
-	jr nz, .next1
-	ld a, [hli]
-	cp d
-	jr nz, .next2
-	ld a, [hli]
-	cp e
-	jr nz, .loop
-	ld a, c
-	ret
-.next1
-	inc hl
-.next2
-	inc hl
-	jr .loop
diff --git a/engine/overworld/hidden_objects.asm b/engine/overworld/hidden_objects.asm
index 66815b60..84108986 100755
--- a/engine/overworld/hidden_objects.asm
+++ b/engine/overworld/hidden_objects.asm
@@ -1,11 +1,11 @@
 ; if a hidden object was found, stores $00 in [hDidntFindAnyHiddenObject], else stores $ff
-CheckForHiddenObject:
+CheckForHiddenObject::
 	ld hl, hItemAlreadyFound
 	xor a
-	ld [hli], a
-	ld [hli], a
-	ld [hli], a
-	ld [hl], a
+	ld [hli], a ; [hItemAlreadyFound]
+	ld [hli], a ; [hSavedMapTextPtr]
+	ld [hli], a ; [hSavedMapTextPtr + 1]
+	ld [hl], a  ; [hDidntFindAnyHiddenObject]
 	ld hl, HiddenObjectMaps
 	ld de, 3
 	ld a, [wCurMap]
@@ -32,7 +32,7 @@ CheckForHiddenObject:
 	ld [wHiddenObjectX], a
 	ld c, a
 	call CheckIfCoordsInFrontOfPlayerMatch
-	ld a, [hCoordsInFrontOfPlayerMatch]
+	ldh a, [hCoordsInFrontOfPlayerMatch]
 	and a
 	jr z, .foundMatchingObject
 	inc hl
@@ -55,13 +55,13 @@ CheckForHiddenObject:
 	ret
 .noMatch
 	ld a, $ff
-	ld [hDidntFindAnyHiddenObject], a
+	ldh [hDidntFindAnyHiddenObject], a
 	ret
 
 ; checks if the coordinates in front of the player's sprite match Y in b and X in c
 ; [hCoordsInFrontOfPlayerMatch] = $00 if they match, $ff if they don't match
 CheckIfCoordsInFrontOfPlayerMatch:
-	ld a, [wSpritePlayerStateData1FacingDirection] ; player's sprite facing direction
+	ld a, [wSpritePlayerStateData1FacingDirection]
 	cp SPRITE_FACING_UP
 	jr z, .facingUp
 	cp SPRITE_FACING_LEFT
@@ -101,7 +101,7 @@ CheckIfCoordsInFrontOfPlayerMatch:
 .didNotMatch
 	ld a, $ff
 .done
-	ld [hCoordsInFrontOfPlayerMatch], a
+	ldh [hCoordsInFrontOfPlayerMatch], a
 	ret
 
-INCLUDE "data/hidden_objects.asm"
+INCLUDE "data/events/hidden_objects.asm"
diff --git a/engine/overworld/item.asm b/engine/overworld/item.asm
deleted file mode 100644
index 9f19100a..00000000
--- a/engine/overworld/item.asm
+++ /dev/null
@@ -1,54 +0,0 @@
-PickUpItem:
-	call EnableAutoTextBoxDrawing
-
-	ld a, [hSpriteIndexOrTextID]
-	ld b, a
-	ld hl, wMissableObjectList
-.missableObjectsListLoop
-	ld a, [hli]
-	cp $ff
-	ret z
-	cp b
-	jr z, .isMissable
-	inc hl
-	jr .missableObjectsListLoop
-
-.isMissable
-	ld a, [hl]
-	ld [$ffdb], a
-
-	ld hl, wMapSpriteExtraData
-	ld a, [hSpriteIndexOrTextID]
-	dec a
-	add a
-	ld d, 0
-	ld e, a
-	add hl, de
-	ld a, [hl]
-	ld b, a ; item
-	ld c, 1 ; quantity
-	call GiveItem
-	jr nc, .BagFull
-
-	ld a, [$ffdb]
-	ld [wMissableObjectIndex], a
-	predef HideObject
-	ld a, 1
-	ld [wDoNotWaitForButtonPressAfterDisplayingText], a
-	ld hl, FoundItemText
-	jr .print
-
-.BagFull
-	ld hl, NoMoreRoomForItemText
-.print
-	call PrintText
-	ret
-
-FoundItemText:
-	TX_FAR _FoundItemText
-	TX_SFX_ITEM_1
-	db "@"
-
-NoMoreRoomForItemText:
-	TX_FAR _NoMoreRoomForItemText
-	db "@"
diff --git a/engine/overworld/ledges.asm b/engine/overworld/ledges.asm
index a44ddf8b..9925c528 100755
--- a/engine/overworld/ledges.asm
+++ b/engine/overworld/ledges.asm
@@ -1,4 +1,4 @@
-HandleLedges:
+HandleLedges::
 	ld a, [wd736]
 	bit 6, a ; already jumping down ledge
 	ret nz
@@ -8,7 +8,7 @@ HandleLedges:
 	predef GetTileAndCoordsInFrontOfPlayer
 	ld a, [wSpritePlayerStateData1FacingDirection]
 	ld b, a
-	aCoord 8, 9
+	lda_coord 8, 9
 	ld c, a
 	ld a, [wTileInFrontOfPlayer]
 	ld d, a
@@ -36,7 +36,7 @@ HandleLedges:
 	inc hl
 	jr .loop
 .foundMatch
-	ld a, [hJoyHeld]
+	ldh a, [hJoyHeld]
 	and e
 	ret z
 	ld a, $ff
@@ -54,20 +54,10 @@ HandleLedges:
 	call PlaySound
 	ret
 
-	; (player direction) (tile player standing on) (ledge tile) (input required)
-LedgeTiles:
-	db SPRITE_FACING_DOWN, $2C,$37,D_DOWN
-	db SPRITE_FACING_DOWN, $39,$36,D_DOWN
-	db SPRITE_FACING_DOWN, $39,$37,D_DOWN
-	db SPRITE_FACING_LEFT, $2C,$27,D_LEFT
-	db SPRITE_FACING_LEFT, $39,$27,D_LEFT
-	db SPRITE_FACING_RIGHT,$2C,$0D,D_RIGHT
-	db SPRITE_FACING_RIGHT,$2C,$1D,D_RIGHT
-	db SPRITE_FACING_RIGHT,$39,$0D,D_RIGHT
-	db $FF
+INCLUDE "data/tilesets/ledge_tiles.asm"
 
 LoadHoppingShadowOAM:
-	ld hl, vChars1 + $7f0
+	ld hl, vChars1 tile $7f
 	ld de, LedgeHoppingShadow
 	lb bc, BANK(LedgeHoppingShadow), (LedgeHoppingShadowEnd - LedgeHoppingShadow) / $8
 	call CopyVideoDataDouble
@@ -81,10 +71,10 @@ LoadHoppingShadowOAM:
 	ret
 
 LedgeHoppingShadow:
-	INCBIN "gfx/ledge_hopping_shadow.1bpp"
+	INCBIN "gfx/overworld/shadow.1bpp"
 LedgeHoppingShadowEnd:
 
 LedgeHoppingShadowOAM:
-	db $58,$48,$FF,$00
-	db $58,$50,$FF,$20
+	dbsprite  9, 11,  0,  0, $ff, 0
+	dbsprite 10, 11,  0,  0, $ff, OAM_HFLIP
 LedgeHoppingShadowOAMEnd:
diff --git a/engine/overworld/map_sprites.asm b/engine/overworld/map_sprites.asm
index 3e2c3912..e31c0bd2 100755
--- a/engine/overworld/map_sprites.asm
+++ b/engine/overworld/map_sprites.asm
@@ -8,7 +8,7 @@
 ; fields, respectively, within loops. The X is the loop index.
 ; If there is an inner loop, Y is the inner loop index, i.e. $C1Y* and $C2Y*
 ; denote fields of the sprite slots iterated over in the inner loop.
-_InitMapSprites:
+_InitMapSprites::
 	call InitOutsideMapSprites
 	ret c ; return if the map is an outside map (already handled by above call)
 ; if the map is an inside map (i.e. mapID >= $25)
@@ -21,7 +21,7 @@ _InitMapSprites:
 ; sets carry if the map is a city or route, unsets carry if not
 InitOutsideMapSprites:
 	ld a, [wCurMap]
-	cp a, REDS_HOUSE_1F ; is the map a city or a route (map ID less than $25)?
+	cp FIRST_INDOOR_MAP ; is the map a city or a route?
 	ret nc ; if not, return
 	call GetSplitMapSpriteSetID
 ; if so, choose the appropriate one
@@ -68,7 +68,7 @@ LoadSpriteSetFromMapHeader:
 	ld a, 14
 .storeVRAMSlotsLoop
 	push af
-	ld a, [hl] ; $C1X0 (picture ID) (zero if sprite slot is not used)
+	ld a, [hl] ; [x#SPRITESTATEDATA1_PICTUREID] (zero if sprite slot is not used)
 	and a ; is the sprite slot used?
 	jr z, .continue ; if the sprite slot is not used
 	ld c, a
@@ -125,7 +125,7 @@ CheckForFourTileSprite:
 	cp SPRITE_PIKACHU       ; is this the Pikachu Sprite?
 	ret z                   ; return if yes
 
-	cp SPRITE_BALL          ; is this a four tile sprite?
+	cp FIRST_STILL_SPRITE   ; is this a four tile sprite?
 	jr nc, .notYellowSprite ; set carry if yes
 ; regular sprite
 	and a
@@ -138,7 +138,7 @@ CheckForFourTileSprite:
 LoadMapSpriteTilePatterns:
 	ld a, 0
 .loop
-	ld [hVRAMSlot], a
+	ldh [hVRAMSlot], a
 	cp 9
 	jr nc, .fourTileSprite
 	call LoadStillTilePattern
@@ -148,7 +148,7 @@ LoadMapSpriteTilePatterns:
 .fourTileSprite
 	call LoadStillTilePattern
 .continue
-	ld a, [hVRAMSlot]
+	ldh a, [hVRAMSlot]
 	inc a
 	cp 11
 	jr nz, .loop
@@ -157,12 +157,12 @@ LoadMapSpriteTilePatterns:
 ReloadWalkingTilePatterns:
 	xor a
 .loop
-	ld [hVRAMSlot], a
+	ldh [hVRAMSlot], a
 	cp 9
 	jr nc, .fourTileSprite
 	call LoadWalkingTilePattern
 .fourTileSprite
-	ld a, [hVRAMSlot]
+	ldh a, [hVRAMSlot]
 	inc a
 	cp 11
 	jr nz, .loop
@@ -192,7 +192,7 @@ LoadWalkingTilePattern:
 
 GetSpriteVRAMAddress:
 	push bc
-	ld a, [hVRAMSlot]
+	ldh a, [hVRAMSlot]
 	ld c, a
 	ld b, 0
 	ld hl, SpriteVRAMAddresses
@@ -220,7 +220,7 @@ SpriteVRAMAddresses:
 	dw vChars0 + $7c0 ; 4-tile sprites
 
 ReadSpriteSheetData:
-	ld a, [hVRAMSlot]
+	ldh a, [hVRAMSlot]
 	ld e, a
 	ld d, 0
 	ld hl, wSpriteSet
@@ -257,20 +257,20 @@ Func_14150:
 	ld a, $e
 	ld hl, wSprite01StateData1
 .loop
-	ld [hVRAMSlot], a ; store current sprite set slot as a counter
-	ld a, [hl] ; $c1x0 (picture ID)
+	ldh [hVRAMSlot], a ; store current sprite set slot as a counter
+	ld a, [hl] ; [x#SPRITESTATEDATA1_PICTUREID]
 	and a ; is the sprite unused?
 	jr z, .spriteUnused
 	call Func_14179
 	push hl
 	ld de, (wSpritePlayerStateData2ImageBaseOffset) - (wSpriteStateData1) ; $10e
-	add hl, de ; get $c2xe (sprite image base offset)
+	add hl, de ; [x#SPRITESTATEDATA2_IMAGEBASEOFFSET]
 	ld [hl], a ; write offset
 	pop hl
 .spriteUnused
 	ld de, wSprite02StateData1 - wSprite01StateData1
 	add hl, de
-	ld a, [hVRAMSlot]
+	ldh a, [hVRAMSlot]
 	dec a
 	jr nz, .loop
 	ret
@@ -364,4 +364,6 @@ GetSplitMapSpriteSetID:
 	ld a, $01
 	ret
 
-INCLUDE "data/sprite_sets.asm"
+INCLUDE "data/maps/sprite_sets.asm"
+
+INCLUDE "data/sprites/sprites.asm"
diff --git a/engine/overworld/missable_objects.asm b/engine/overworld/missable_objects.asm
index dd601451..358a9b9f 100644
--- a/engine/overworld/missable_objects.asm
+++ b/engine/overworld/missable_objects.asm
@@ -1,6 +1,6 @@
-MarkTownVisitedAndLoadMissableObjects:
+MarkTownVisitedAndLoadMissableObjects::
 	ld a, [wCurMap]
-	cp ROUTE_1
+	cp FIRST_ROUTE_MAP
 	jr nc, .notInTown
 	ld c, a
 	ld b, FLAG_SET
@@ -22,31 +22,31 @@ MarkTownVisitedAndLoadMissableObjects:
 	ld l, a
 	push hl
 	ld a, l
-	sub MapHS00 & $ff ; calculate difference between out pointer and the base pointer
+	sub MissableObjects & $ff ; calculate difference between out pointer and the base pointer
 	ld l, a
 	ld a, h
-	sbc MapHS00 / $100
+	sbc MissableObjects / $100
 	ld h, a
 	ld a, h
-	ld [H_DIVIDEND], a
+	ldh [hDividend], a
 	ld a, l
-	ld [H_DIVIDEND + 1], a
+	ldh [hDividend+1], a
 	xor a
-	ld [H_DIVIDEND + 2], a
-	ld [H_DIVIDEND + 3], a
+	ldh [hDividend+2], a
+	ldh [hDividend+3], a
 	ld a, $3
-	ld [H_DIVISOR], a
+	ldh [hDivisor], a
 	ld b, $2
 	call Divide                ; divide difference by 3, resulting in the global offset (number of missable items before ours)
 	ld a, [wCurMap]
 	ld b, a
-	ld a, [H_DIVIDEND + 3]
+	ldh a, [hDividend+3]
 	ld c, a                    ; store global offset in c
 	ld de, wMissableObjectList
 	pop hl
 .writeMissableObjectsListLoop
 	ld a, [hli]
-	cp $ff
+	cp -1
 	jr z, .done     ; end of list
 	cp b
 	jr nz, .done    ; not for current map anymore
@@ -60,7 +60,7 @@ MarkTownVisitedAndLoadMissableObjects:
 	inc de
 	jr .writeMissableObjectsListLoop
 .done
-	ld a, $ff
+	ld a, -1
 	ld [de], a                 ; write sentinel
 	ret
 
@@ -69,17 +69,17 @@ InitializeMissableObjectsFlags:
 	ld bc, wMissableObjectFlagsEnd - wMissableObjectFlags
 	xor a
 	call FillMemory ; clear missable objects flags
-	ld hl, MapHS00
+	ld hl, MissableObjects
 	xor a
 	ld [wMissableObjectCounter], a
 .missableObjectsLoop
 	ld a, [hli]
-	cp $ff          ; end of list
+	cp -1           ; end of list
 	ret z
 	push hl
 	inc hl
 	ld a, [hl]
-	cp Hide
+	cp HIDE
 	jr nz, .skip
 	ld hl, wMissableObjectFlags
 	ld a, [wMissableObjectCounter]
@@ -96,13 +96,13 @@ InitializeMissableObjectsFlags:
 
 ; tests if current sprite is a missable object that is hidden/has been removed
 IsObjectHidden:
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	swap a
 	ld b, a
 	ld hl, wMissableObjectList
 .loop
 	ld a, [hli]
-	cp $ff
+	cp -1
 	jr z, .notHidden ; not missable -> not hidden
 	cp b
 	ld a, [hli]
@@ -117,7 +117,7 @@ IsObjectHidden:
 .notHidden
 	xor a
 .hidden
-	ld [$ffe5], a
+	ldh [hIsHiddenMissableObject], a
 	ret
 
 ; adds missable object (items, leg. pokemon, etc.) to the map
diff --git a/engine/overworld/movement.asm b/engine/overworld/movement.asm
index f2334479..dadf2194 100644
--- a/engine/overworld/movement.asm
+++ b/engine/overworld/movement.asm
@@ -1,25 +1,25 @@
 MAP_TILESET_SIZE EQU $60
 
 UpdatePlayerSprite:
-	ld a, [wSpriteStateData2]
+	ld a, [wSpritePlayerStateData2WalkAnimationCounter]
 	and a
 	jr z, .checkIfTextBoxInFrontOfSprite
 	cp $ff
 	jr z, .disableSprite
 	dec a
-	ld [wSpriteStateData2], a
+	ld [wSpritePlayerStateData2WalkAnimationCounter], a
 	jr .disableSprite
 ; check if a text box is in front of the sprite by checking if the lower left
 ; background tile the sprite is standing on is greater than $5F, which is
 ; the maximum number for map tiles
 .checkIfTextBoxInFrontOfSprite
-	aCoord 8, 9
-	ld [hTilePlayerStandingOn], a
+	lda_coord 8, 9
+	ldh [hTilePlayerStandingOn], a
 	cp MAP_TILESET_SIZE
 	jr c, .lowerLeftTileIsMapTile
 .disableSprite
 	ld a, $ff
-	ld [wSpriteStateData1 + 2], a
+	ld [wSpritePlayerStateData1ImageIndex], a
 	ret
 .lowerLeftTileIsMapTile
 	ld a, [wUpdateSpritesEnabled]
@@ -29,7 +29,7 @@ UpdatePlayerSprite:
 	call DetectCollisionBetweenSprites
 	pop af
 	ld [wUpdateSpritesEnabled], a
-	ld h, wSpriteStateData1 / $100
+	ld h, HIGH(wSpriteStateData1)
 	ld a, [wWalkCounter]
 	and a
 	jr nz, .moving
@@ -62,8 +62,8 @@ UpdatePlayerSprite:
 .notMoving
 ; zero the animation counters
 	xor a
-	ld [wSpriteStateData1 + 7], a
-	ld [wSpriteStateData1 + 8], a
+	ld [wSpritePlayerStateData1IntraAnimFrameCounter], a
+	ld [wSpritePlayerStateData1AnimFrameCounter], a
 	call Func_4e32
 	jr .skipSpriteAnim
 .moving
@@ -77,27 +77,27 @@ UpdatePlayerSprite:
 ; lower priority than the background so that it's partially obscured by the
 ; grass. Only the lower half of the sprite is permitted to have the priority
 ; bit set by later logic.
-	ld a, [hTilePlayerStandingOn]
+	ldh a, [hTilePlayerStandingOn]
 	ld c, a
 	ld a, [wGrassTile]
 	cp c
-	ld a, $0
+	ld a, 0
 	jr nz, .next2
-	ld a, $80
+	ld a, OAM_BEHIND_BG
 .next2
-	ld [wSpriteStateData2 + $07], a
+	ld [wSpritePlayerStateData2GrassPriority], a
 	ret
 
 Func_4e32:
-	ld a, [wSpriteStateData1 + 8]
+	ld a, [wSpritePlayerStateData1AnimFrameCounter]
 	ld b, a
 	ld a, [wSpritePlayerStateData1FacingDirection]
 	add b
-	ld [wSpriteStateData1 + 2], a
+	ld [wSpritePlayerStateData1ImageIndex], a
 	ret
 
 UpdateNPCSprite:
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	swap a
 	dec a
 	add a
@@ -106,20 +106,20 @@ UpdateNPCSprite:
 	ld l, a
 	ld a, [hl]        ; read movement byte 2
 	ld [wCurSpriteMovement2], a
-	ld h, wSpriteStateData1 / $100
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ld h, HIGH(wSpriteStateData1)
+	ldh a, [hCurrentSpriteOffset]
 	ld l, a
 	inc l
-	ld a, [hl]        ; c1x1
+	ld a, [hl]        ; x#SPRITESTATEDATA1_MOVEMENTSTATUS
 	and a
 	jp z, InitializeSpriteStatus
 	call CheckSpriteAvailability
 	ret c             ; if sprite is invisible, on tile >=MAP_TILESET_SIZE, in grass or player is currently walking
-	ld h, wSpriteStateData1 / $100
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ld h, HIGH(wSpriteStateData1)
+	ldh a, [hCurrentSpriteOffset]
 	ld l, a
 	inc l
-	ld a, [hl]        ; c1x1
+	ld a, [hl]        ; x#SPRITESTATEDATA1_MOVEMENTSTATUS
 	bit 7, a ; is the face player flag set?
 	jp nz, MakeNPCFacePlayer
 	ld b, a
@@ -128,24 +128,24 @@ UpdateNPCSprite:
 	jp nz, notYetMoving
 	ld a, b
 	cp $2
-	jp z, UpdateSpriteMovementDelay  ; c1x1 == 2
+	jp z, UpdateSpriteMovementDelay  ; [x#SPRITESTATEDATA1_MOVEMENTSTATUS] == 2
 	cp $3
-	jp z, UpdateSpriteInWalkingAnimation  ; c1x1 == 3
+	jp z, UpdateSpriteInWalkingAnimation  ; [x#SPRITESTATEDATA1_MOVEMENTSTATUS] == 3
 	cp $4
 	jp z, Func_5357
 	ld a, [wWalkCounter]
 	and a
 	ret nz           ; don't do anything yet if player is currently moving (redundant, already tested in CheckSpriteAvailability)
 	call InitializeSpriteScreenPosition
-	ld h, wSpriteStateData2 / $100
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ld h, HIGH(wSpriteStateData2)
+	ldh a, [hCurrentSpriteOffset]
 	add $6
 	ld l, a
-	ld a, [hl]       ; c2x6: movement byte 1
+	ld a, [hl]       ; x#SPRITESTATEDATA2_MOVEMENTBYTE1
 	inc a
-	jp z, .randomMovement  ; value $FF
+	jp z, .randomMovement  ; value STAY
 	inc a
-	jp z, .randomMovement  ; value $FE
+	jp z, .randomMovement  ; value WALK
 ; scripted movement
 	dec a
 	ld [hl], a       ; increment movement byte 1 (movement data index)
@@ -156,7 +156,7 @@ UpdateNPCSprite:
 	pop hl
 	ld de, wNPCMovementDirections
 	call LoadDEPlusA ; a = [wNPCMovementDirections + movement byte 1]
-	cp $e0
+	cp NPC_CHANGE_FACING
 	jp z, ChangeFacingDirection
 	cp STAY
 	jr nz, .next
@@ -171,7 +171,7 @@ UpdateNPCSprite:
 .next
 	cp WALK
 	jr nz, .asm_4ecb
-; current NPC movement data is $fe. this seems buggy
+; current NPC movement data is WALK ($fe). this seems buggy
 	ld [hl], $1     ; set movement byte 1 to $1
 	ld de, wNPCMovementDirections
 	call LoadDEPlusA ; a = [wNPCMovementDirections + $fe] (?)
@@ -188,20 +188,20 @@ UpdateNPCSprite:
 .determineDirection
 	ld b, a
 	ld a, [wCurSpriteMovement2]
-	cp $d0
-	jr z, .moveDown    ; movement byte 2 = $d0 forces down
-	cp $d1
-	jr z, .moveUp      ; movement byte 2 = $d1 forces up
-	cp $d2
-	jr z, .moveLeft    ; movement byte 2 = $d2 forces left
-	cp $d3
-	jr z, .moveRight   ; movement byte 2 = $d3 forces right
+	cp DOWN
+	jr z, .moveDown
+	cp UP
+	jr z, .moveUp
+	cp LEFT
+	jr z, .moveLeft
+	cp RIGHT
+	jr z, .moveRight
 	ld a, b
-	cp $40             ; a < $40: down (or left)
+	cp NPC_MOVEMENT_UP ; NPC_MOVEMENT_DOWN <= a < NPC_MOVEMENT_UP: down (or left)
 	jr nc, .notDown
 	ld a, [wCurSpriteMovement2]
-	cp $2
-	jr z, .moveLeft    ; movement byte 2 = $2 only allows left or right
+	cp LEFT_RIGHT
+	jr z, .moveLeft
 .moveDown
 	ld de, 2*SCREEN_WIDTH
 	add hl, de         ; move tile pointer two rows down
@@ -209,11 +209,11 @@ UpdateNPCSprite:
 	lb bc, 4, SPRITE_FACING_DOWN
 	jr TryWalking
 .notDown
-	cp $80             ; $40 <= a < $80: up (or right)
+	cp NPC_MOVEMENT_LEFT ; NPC_MOVEMENT_UP <= a < NPC_MOVEMENT_LEFT: up (or right)
 	jr nc, .notUp
 	ld a, [wCurSpriteMovement2]
-	cp $2
-	jr z, .moveRight   ; movement byte 2 = $2 only allows left or right
+	cp LEFT_RIGHT
+	jr z, .moveRight
 .moveUp
 	ld de, -2*SCREEN_WIDTH
 	add hl, de         ; move tile pointer two rows up
@@ -221,21 +221,21 @@ UpdateNPCSprite:
 	lb bc, 8, SPRITE_FACING_UP
 	jr TryWalking
 .notUp
-	cp $c0             ; $80 <= a < $c0: left (or up)
+	cp NPC_MOVEMENT_RIGHT ; NPC_MOVEMENT_LEFT <= a < NPC_MOVEMENT_RIGHT: left (or up)
 	jr nc, .notLeft
 	ld a, [wCurSpriteMovement2]
-	cp $1
-	jr z, .moveUp      ; movement byte 2 = $1 only allows up or down
+	cp UP_DOWN
+	jr z, .moveUp
 .moveLeft
 	dec hl
 	dec hl             ; move tile pointer two columns left
 	lb de, 0, -1
 	lb bc, 2, SPRITE_FACING_LEFT
 	jr TryWalking
-.notLeft              ; $c0 <= a: right (or down)
+.notLeft               ; NPC_MOVEMENT_RIGHT <= a: right (or down)
 	ld a, [wCurSpriteMovement2]
-	cp $1
-	jr z, .moveDown    ; movement byte 2 = $1 only allows up or down
+	cp UP_DOWN
+	jr z, .moveDown
 .moveRight
 	inc hl
 	inc hl             ; move tile pointer two columns right
@@ -262,103 +262,104 @@ TryWalking:
 	ld c, [hl]
 	call CanWalkOntoTile
 	pop de
-	ret c
+	ret c               ; cannot walk there (reinitialization of delay values already done)
 	call Func_5349
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	ld l, a
-	ld [hl], $10          ; c1x9 (update facing direction)
+	ld [hl], $10        ; [x#SPRITESTATEDATA2_WALKANIMATIONCOUNTER] = 16
 	dec h
 	inc l
-	ld [hl], $3
+	ld [hl], $3         ; x#SPRITESTATEDATA1_MOVEMENTSTATUS
 	jp UpdateSpriteImage
 
 ; update the walking animation parameters for a sprite that is currently walking
 UpdateSpriteInWalkingAnimation:
 	call Func_5274
-.noNextAnimationFrame
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	add $3
 	ld l, a
-	ld a, [hli]                      ; c1x3 (movement Y delta)
+	ld a, [hli]                      ; x#SPRITESTATEDATA1_YSTEPVECTOR
 	ld b, a
-	ld a, [hl]                       ; c1x4 (screen Y position)
+	ld a, [hl]                       ; x#SPRITESTATEDATA1_YPIXELS
 	add b
-	ld [hli], a                      ; update screen Y position
-	ld a, [hli]                      ; c1x5 (movement X delta)
+	ld [hli], a                      ; update [x#SPRITESTATEDATA1_YPIXELS]
+	ld a, [hli]                      ; x#SPRITESTATEDATA1_XSTEPVECTOR
 	ld b, a
-	ld a, [hl]                       ; c1x6 (screen X position)
+	ld a, [hl]                       ; x#SPRITESTATEDATA1_XPIXELS
 	add b
-	ld [hl], a                       ; update screen X position
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ld [hl], a                       ; update [x#SPRITESTATEDATA1_XPIXELS]
+	ldh a, [hCurrentSpriteOffset]
 	ld l, a
 	inc h
-	ld a, [hl]                       ; c2x0 (walk animation counter)
+	ld a, [hl]                       ; x#SPRITESTATEDATA2_WALKANIMATIONCOUNTER
 	dec a
 	ld [hl], a                       ; update walk animation counter
 	ret nz
 	ld a, $6                         ; walking finished, update state
 	add l
 	ld l, a
-	ld a, [hl]                       ; c2x6 (movement byte 1)
-	cp $fe
-	jr nc, .initNextMovementCounter  ; values $fe and $ff
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ld a, [hl]                       ; x#SPRITESTATEDATA2_MOVEMENTBYTE1
+	cp WALK
+	jr nc, .initNextMovementCounter  ; values WALK or STAY
+	ldh a, [hCurrentSpriteOffset]
 	inc a
 	ld l, a
 	dec h
-	ld [hl], $1                      ; c1x1 = 1 (movement status ready)
+	ld [hl], $1                      ; [x#SPRITESTATEDATA1_MOVEMENTSTATUS] = 1 (movement status ready)
 	ret
 .initNextMovementCounter
 	call Random
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	add $8
 	ld l, a
-	ld a, [hRandomAdd]
+	ldh a, [hRandomAdd]
 	and $7f
-	ld [hl], a                       ; c2x8: set next movement delay to a random value in [0,$7f]
-	dec h                            ;       note that value 0 actually makes the delay $100 (bug?)
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ld [hl], a                       ; x#SPRITESTATEDATA2_MOVEMENTDELAY:
+	                                 ; set next movement delay to a random value in [0,$7f]
+	                                 ; note that value 0 actually makes the delay $100 (bug?)
+	dec h ; HIGH(wSpriteStateData1)
+	ldh a, [hCurrentSpriteOffset]
 	inc a
 	ld l, a
-	ld [hl], $2                      ; c1x1 = 2 (movement status)
+	ld [hl], $2                      ; [x#SPRITESTATEDATA1_MOVEMENTSTATUS] = 2 (movement status)
 	inc l
 	inc l
 	xor a
-	ld b, [hl]                       ; c1x3 (movement Y delta)
-	ld [hli], a                      ; reset movement Y delta
+	ld b, [hl]                       ; x#SPRITESTATEDATA1_YSTEPVECTOR
+	ld [hli], a                      ; [x#SPRITESTATEDATA1_YSTEPVECTOR] = 0
 	inc l
-	ld c, [hl]                       ; c1x5 (movement X delta)
-	ld [hl], a                       ; reset movement X delta
+	ld c, [hl]                       ; x#SPRITESTATEDATA1_XSTEPVECTOR
+	ld [hl], a                       ; [x#SPRITESTATEDATA1_XSTEPVECTOR] = 0
 	ret
 
-; update delay value (c2x8) for sprites in the delayed state (c1x1)
+; update [x#SPRITESTATEDATA2_MOVEMENTDELAY] for sprites in the delayed state (x#SPRITESTATEDATA1_MOVEMENTSTATUS)
 UpdateSpriteMovementDelay:
-	ld h, $c2
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ld h, HIGH(wSpriteStateData2)
+	ldh a, [hCurrentSpriteOffset]
 	add $6
 	ld l, a
-	ld a, [hl]              ; c2x6: movement byte 1
+	ld a, [hl]              ; x#SPRITESTATEDATA2_MOVEMENTBYTE1
 	inc l
 	inc l
-	cp $fe
-	jr nc, .tickMoveCounter ; values $fe or $ff
+	cp WALK
+	jr nc, .tickMoveCounter ; values WALK or STAY
 	ld [hl], $0
 	jr .moving
 .tickMoveCounter
-	dec [hl]                ; c2x8: frame counter until next movement
+	dec [hl]                ; x#SPRITESTATEDATA2_MOVEMENTDELAY
 	jr nz, notYetMoving
 .moving
 	dec h
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	inc a
 	ld l, a
-	ld [hl], $1             ; c1x1 = 1 (mark as ready to move)
+	ld [hl], $1             ; [x#SPRITESTATEDATA1_MOVEMENTSTATUS] = 1 (mark as ready to move)
 notYetMoving:
-	ld h, wSpriteStateData1 / $100
-	ld a, [H_CURRENTSPRITEOFFSET]
-	add $8
+	ld h, HIGH(wSpriteStateData1)
+	ldh a, [hCurrentSpriteOffset]
+	add SPRITESTATEDATA1_ANIMFRAMECOUNTER
 	ld l, a
-	ld [hl], $0             ; c1x8 = 0 (walk animation frame)
+	ld [hl], $0             ; [x#SPRITESTATEDATA1_ANIMFRAMECOUNTER] = 0 (walk animation frame)
 	jp UpdateSpriteImage
 
 MakeNPCFacePlayer:
@@ -388,48 +389,48 @@ MakeNPCFacePlayer:
 .notFacingRight
 	ld c, SPRITE_FACING_LEFT
 .facingDirectionDetermined
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	add $9
 	ld l, a
-	ld [hl], c              ; c1x9: set facing direction
+	ld [hl], c              ; [x#SPRITESTATEDATA1_FACINGDIRECTION]: set facing direction
 	jr notYetMoving
 
 InitializeSpriteStatus:
-	ld [hl], $1   ; $c1x1: set movement status to ready
+	ld [hl], $1   ; [x#SPRITESTATEDATA1_MOVEMENTSTATUS] = ready
 	inc l
-	ld [hl], $ff  ; $c1x2: set sprite image to $ff (invisible/off screen)
-	inc h
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ld [hl], $ff  ; [x#SPRITESTATEDATA1_IMAGEINDEX] = invisible/off screen
+	inc h ; HIGH(wSpriteStateData2)
+	ldh a, [hCurrentSpriteOffset]
 	add $2
 	ld l, a
 	ld a, $8
-	ld [hli], a   ; $c2x2: set Y displacement to 8
-	ld [hl], a    ; $c2x3: set X displacement to 8
+	ld [hli], a   ; [x#SPRITESTATEDATA2_YDISPLACEMENT] = 8
+	ld [hl], a    ; [x#SPRITESTATEDATA2_XDISPLACEMENT] = 8
 	call InitializeSpriteScreenPosition ; could have done fallthrough here
 	ret
 
-; calculates the sprite's screen position form its map position and the player position
+; calculates the sprite's screen position from its map position and the player position
 InitializeSpriteScreenPosition:
-	ld h, wSpriteStateData2 / $100
-	ld a, [H_CURRENTSPRITEOFFSET]
-	add $4
+	ld h, HIGH(wSpriteStateData2)
+	ldh a, [hCurrentSpriteOffset]
+	add SPRITESTATEDATA2_MAPY
 	ld l, a
 	ld a, [wYCoord]
 	ld b, a
-	ld a, [hl]      ; c2x4 (Y position + 4)
+	ld a, [hl]      ; x#SPRITESTATEDATA2_MAPY
 	sub b           ; relative to player position
 	call Func_5033
 	sub $4          ; - 4
 	dec h
-	ld [hli], a     ; c1x4 (screen Y position)
+	ld [hli], a     ; [x#SPRITESTATEDATA1_YPIXELS]
 	inc h
 	ld a, [wXCoord]
 	ld b, a
-	ld a, [hli]     ; c2x6 (X position + 4)
+	ld a, [hli]     ; x#SPRITESTATEDATA2_MAPX
 	sub b           ; relative to player position
 	call Func_5033
 	dec h
-	ld [hl], a      ; c1x6 (screen X position)
+	ld [hl], a      ; [x#SPRITESTATEDATA1_XPIXELS]
 	ret
 
 Func_5033:
@@ -447,35 +448,35 @@ Func_5033:
 ; tests if sprite is off screen or otherwise unable to do anything
 CheckSpriteAvailability:
 	predef IsObjectHidden
-	ld a, [$ffe5]
+	ldh a, [hIsHiddenMissableObject]
 	and a
 	jp nz, .spriteInvisible
-	ld h, wSpriteStateData2 / $100
-	ld a, [H_CURRENTSPRITEOFFSET]
-	add $6
+	ld h, HIGH(wSpriteStateData2)
+	ldh a, [hCurrentSpriteOffset]
+	add SPRITESTATEDATA2_MOVEMENTBYTE1
 	ld l, a
-	ld a, [hl]      ; c2x6: movement byte 1
-	cp $fe
-	jr c, .skipXVisibilityTest ; movement byte 1 < $fe (i.e. the sprite's movement is scripted)
-	ld a, [H_CURRENTSPRITEOFFSET]
-	add $4
+	ld a, [hl]      ; x#SPRITESTATEDATA2_MOVEMENTBYTE1
+	cp WALK
+	jr c, .skipXVisibilityTest ; movement byte 1 < WALK (i.e. the sprite's movement is scripted)
+	ldh a, [hCurrentSpriteOffset]
+	add SPRITESTATEDATA2_MAPY
 	ld l, a
-	ld b, [hl]      ; c2x4: Y pos (+4)
+	ld b, [hl]      ; x#SPRITESTATEDATA2_MAPY
 	ld a, [wYCoord]
 	cp b
 	jr z, .skipYVisibilityTest
 	jr nc, .spriteInvisible ; above screen region
-	add $8                  ; screen is 9 tiles high
+	add SCREEN_HEIGHT / 2 - 1
 	cp b
 	jr c, .spriteInvisible  ; below screen region
 .skipYVisibilityTest
 	inc l
-	ld b, [hl]      ; c2x5: X pos (+4)
+	ld b, [hl]      ; x#SPRITESTATEDATA2_MAPX
 	ld a, [wXCoord]
 	cp b
 	jr z, .skipXVisibilityTest
 	jr nc, .spriteInvisible ; left of screen region
-	add $9                  ; screen is 10 tiles wide
+	add SCREEN_WIDTH / 2 - 1
 	cp b
 	jr c, .spriteInvisible  ; right of screen region
 .skipXVisibilityTest
@@ -489,7 +490,7 @@ CheckSpriteAvailability:
 	ld a, [hld]
 	cp d
 	jr nc, .spriteInvisible ; standing on tile with ID >=MAP_TILESET_SIZE (bottom right tile)
-	ld bc, -20
+	ld bc, -SCREEN_WIDTH
 	add hl, bc              ; go back one row of tiles
 	ld a, [hli]
 	cp d
@@ -498,11 +499,11 @@ CheckSpriteAvailability:
 	cp d
 	jr c, .spriteVisible    ; standing on tile with ID >=MAP_TILESET_SIZE (top right tile)
 .spriteInvisible
-	ld h, wSpriteStateData1 / $100
-	ld a, [H_CURRENTSPRITEOFFSET]
-	add $2
+	ld h, HIGH(wSpriteStateData1)
+	ldh a, [hCurrentSpriteOffset]
+	add SPRITESTATEDATA1_IMAGEINDEX
 	ld l, a
-	ld [hl], $ff       ; c1x2
+	ld [hl], $ff       ; x#SPRITESTATEDATA1_IMAGEINDEX
 	scf
 	jr .done
 .spriteVisible
@@ -512,37 +513,37 @@ CheckSpriteAvailability:
 	jr nz, .done           ; if player is currently walking, we're done
 	call UpdateSpriteImage
 	inc h
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	add $7
 	ld l, a
 	ld a, [wGrassTile]
 	cp c
-	ld a, $0
+	ld a, 0
 	jr nz, .notInGrass
-	ld a, $80
+	ld a, OAM_BEHIND_BG
 .notInGrass
-	ld [hl], a       ; c2x7
+	ld [hl], a       ; x#SPRITESTATEDATA2_GRASSPRIORITY
 	and a
 .done
 	ret
 
 UpdateSpriteImage:
-	ld h, $c1
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ld h, HIGH(wSpriteStateData1)
+	ldh a, [hCurrentSpriteOffset]
 	add $8
 	ld l, a
-	ld a, [hli]        ; c1x8: walk animation frame
+	ld a, [hli]        ; x#SPRITESTATEDATA1_ANIMFRAMECOUNTER
 	ld b, a
-	ld a, [hl]         ; c1x9: facing direction
+	ld a, [hl]         ; x#SPRITESTATEDATA1_FACINGDIRECTION
 	add b
 	ld b, a
-	ld a, [$ff93]  ; current sprite offset
+	ldh a, [hTilePlayerStandingOn]
 	add b
 	ld b, a
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	add $2
 	ld l, a
-	ld [hl], b         ; c1x2: sprite to display
+	ld [hl], b         ; x#SPRITESTATEDATA1_IMAGEINDEX
 	ret
 
 ; tests if sprite can walk the specified direction
@@ -552,37 +553,37 @@ UpdateSpriteImage:
 ; e: X movement delta (-1, 0 or 1)
 ; set carry on failure, clears carry on success
 CanWalkOntoTile:
-	ld h, wSpriteStateData2 / $100
-	ld a, [H_CURRENTSPRITEOFFSET]
-	add $6
+	ld h, HIGH(wSpriteStateData2)
+	ldh a, [hCurrentSpriteOffset]
+	add SPRITESTATEDATA2_MOVEMENTBYTE1
 	ld l, a
-	ld a, [hl]         ; c2x6 (movement byte 1)
-	cp $fe
-	jr nc, .notScripted    ; values $fe and $ff
+	ld a, [hl]         ; x#SPRITESTATEDATA2_MOVEMENTBYTE1
+	cp WALK
+	jr nc, .notScripted    ; values WALK or STAY
 ; always allow walking if the movement is scripted
 	and a
 	ret
 .notScripted
 	call _IsTilePassable
 	jr c, .impassable
-	ld h, wSpriteStateData2 / $100
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ld h, HIGH(wSpriteStateData2)
+	ldh a, [hCurrentSpriteOffset]
 	add $6
 	ld l, a
-	ld a, [hl]         ; $c2x6 (movement byte 1)
+	ld a, [hl]         ; x#SPRITESTATEDATA2_MOVEMENTBYTE1
 	inc a
 	jr z, .impassable  ; if $ff, no movement allowed (however, changing direction is)
-	ld h, wSpriteStateData1 / $100
-	ld a, [H_CURRENTSPRITEOFFSET]
-	add $4
+	ld h, HIGH(wSpriteStateData1)
+	ldh a, [hCurrentSpriteOffset]
+	add SPRITESTATEDATA1_YPIXELS
 	ld l, a
-	ld a, [hli]        ; c1x4 (screen Y pos)
+	ld a, [hli]        ; x#SPRITESTATEDATA1_YPIXELS
 	add $4             ; align to blocks (Y pos is always 4 pixels off)
 	add d              ; add Y delta
 	cp $80             ; if value is >$80, the destination is off screen (either $81 or $FF underflow)
 	jr nc, .impassable ; don't walk off screen
 	inc l
-	ld a, [hl]         ; c1x6 (screen X pos)
+	ld a, [hl]         ; x#SPRITESTATEDATA1_XPIXELS
 	add e              ; add X delta
 	cp $90             ; if value is >$90, the destination is off screen (either $91 or $FF underflow)
 	jr nc, .impassable ; don't walk off screen
@@ -597,30 +598,36 @@ CanWalkOntoTile:
 	ld [wUpdateSpritesEnabled], a
 	pop bc
 	pop de
-	ld h, wSpriteStateData1 / $100
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ld h, HIGH(wSpriteStateData1)
+	ldh a, [hCurrentSpriteOffset]
 	add $c
 	ld l, a
-	ld a, [hl]         ; c1xc (directions in which sprite collision would occur)
+	ld a, [hl]         ; x#SPRITESTATEDATA1_COLLISIONDATA (directions in which sprite collision would occur)
 	and b              ; check against chosen direction (1,2,4 or 8)
 	jr nz, .impassable ; collision between sprites, don't go there
-	ld h, wSpriteStateData2 / $100
-	ld a, [H_CURRENTSPRITEOFFSET]
-	add $2
+	ld h, HIGH(wSpriteStateData2)
+	ldh a, [hCurrentSpriteOffset]
+	add SPRITESTATEDATA2_YDISPLACEMENT
 	ld l, a
-	ld a, [hli]        ; c2x2 (sprite Y displacement, initialized at $8, keep track of where a sprite did go)
+	ld a, [hli]        ; x#SPRITESTATEDATA2_YDISPLACEMENT (initialized at $8, keep track of where a sprite did go)
 	bit 7, d           ; check if going upwards (d=$ff)
 	jr nz, .upwards
 	add d
+	; bug: these tests against $5 probably were supposed to prevent
+	; sprites from walking out too far, but this line makes sprites get
+	; stuck whenever they walked upwards 5 steps
+	; on the other hand, the amount a sprite can walk out to the
+	; right of bottom is not limited (until the counter overflows)
+	; this was fixed in Yellow
 	cp $5
-	;jr c, .impassable (bugfix) ; if c2x2+d < 5, don't go ;bug: this tests probably were supposed to prevent sprites
-	jr .checkHorizontal                          ; from walking out too far, but this line makes sprites get stuck
-.upwards                                         ; whenever they walked upwards 5 steps
-	sub $1                                       ; on the other hand, the amount a sprite can walk out to the
-	jr c, .impassable  ; if d2x2 == 0, don't go  ; right of bottom is not limited (until the counter overflows)
+	;jr c, .impassable  ; if [x#SPRITESTATEDATA2_YDISPLACEMENT]+d < 5, don't go
+	jr .checkHorizontal
+.upwards
+	sub $1
+	jr c, .impassable  ; if [x#SPRITESTATEDATA2_YDISPLACEMENT] == 0, don't go
 .checkHorizontal
 	ld d, a
-	ld a, [hl]         ; c2x3 (sprite X displacement, initialized at $8, keep track of where a sprite did go)
+	ld a, [hl]         ; x#SPRITESTATEDATA2_XDISPLACEMENT (initialized at $8, keep track of where a sprite did go)
 	bit 7, e           ; check if going left (e=$ff)
 	jr nz, .left
 	add e
@@ -628,32 +635,32 @@ CanWalkOntoTile:
 	jr .passable
 .left
 	sub $1
-	jr c, .impassable  ; if d2x3 == 0, don't go
+	jr c, .impassable  ; if [x#SPRITESTATEDATA2_XDISPLACEMENT] == 0, don't go
 .passable
-	ld [hld], a        ; update c2x3
-	ld [hl], d         ; update c2x2
+	ld [hld], a        ; update x#SPRITESTATEDATA2_XDISPLACEMENT
+	ld [hl], d         ; update x#SPRITESTATEDATA2_YDISPLACEMENT
 	and a              ; clear carry (marking success)
 	ret
 .impassable
-	ld h, wSpriteStateData1 / $100
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ld h, HIGH(wSpriteStateData1)
+	ldh a, [hCurrentSpriteOffset]
 	inc a
 	ld l, a
-	ld [hl], $2        ; c1x1 = 2 (set movement status to delayed)
+	ld [hl], $2        ; [x#SPRITESTATEDATA1_MOVEMENTSTATUS] = 2 (delayed)
 	inc l
 	inc l
 	xor a
-	ld [hli], a        ; c1x3 = 0 (clear Y movement delta)
+	ld [hli], a        ; [x#SPRITESTATEDATA1_YSTEPVECTOR] = 0
 	inc l
-	ld [hl], a         ; c1x5 = 0 (clear X movement delta)
+	ld [hl], a         ; [x#SPRITESTATEDATA1_XSTEPVECTOR] = 0
 	inc h
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	add $8
 	ld l, a
 	call Random
-	ld a, [hRandomAdd]
+	ldh a, [hRandomAdd]
 	and $7f
-	ld [hl], a         ; c2x8: set next movement delay to a random value in [0,$7f] (again with delay $100 if value is 0)
+	ld [hl], a         ; x#SPRITESTATEDATA2_MOVEMENTDELAY: set to a random value in [0,$7f] (again with delay $100 if value is 0)
 	scf                ; set carry (marking failure to walk)
 	ret
 
@@ -661,25 +668,25 @@ CanWalkOntoTile:
 ; this is always the lower left tile of the 2x2 tile blocks all sprites are snapped to
 ; hl: output pointer
 GetTileSpriteStandsOn:
-	ld h, wSpriteStateData1 / $100
-	ld a, [H_CURRENTSPRITEOFFSET]
-	add $4
+	ld h, HIGH(wSpriteStateData1)
+	ldh a, [hCurrentSpriteOffset]
+	add SPRITESTATEDATA1_YPIXELS
 	ld l, a
-	ld a, [hli]     ; c1x4: screen Y position
+	ld a, [hli]     ; x#SPRITESTATEDATA1_YPIXELS
 	add $4          ; align to 2*2 tile blocks (Y position is always off 4 pixels to the top)
 	and $f8         ; in case object is currently moving (XXX why changed to $f8?)
 	srl a           ; screen Y tile * 4
 	ld c, a
 	ld b, $0
 	inc l
-	ld a, [hl]      ; c1x6: screen X position
+	ld a, [hl]      ; x#SPRITESTATEDATA1_XPIXELS
 	srl a
 	srl a
 	srl a            ; screen X tile
 	add SCREEN_WIDTH ; screen X tile + 20
 	ld d, $0
 	ld e, a
-	coord hl, 0, 0
+	hlcoord 0, 0
 	add hl, bc
 	add hl, bc
 	add hl, bc
@@ -754,7 +761,7 @@ DoScriptedNPCMovement:
 	ld a, [hl]
 	add b
 	ld [hl], a
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	add $9
 	ld l, a
 	ld a, c
@@ -777,17 +784,17 @@ InitScriptedNPCMovement:
 	jp AnimScriptedNPCMovement
 
 GetSpriteScreenYPointer:
-	ld a, $4
+	ld a, SPRITESTATEDATA1_YPIXELS
 	ld b, a
 	jr GetSpriteScreenXYPointerCommon
 
 GetSpriteScreenXPointer:
-	ld a, $6
+	ld a, SPRITESTATEDATA1_XPIXELS
 	ld b, a
 
 GetSpriteScreenXYPointerCommon:
 	ld hl, wSpriteStateData1
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	add l
 	add b
 	ld l, a
@@ -795,16 +802,16 @@ GetSpriteScreenXYPointerCommon:
 
 AnimScriptedNPCMovement:
 	ld hl, wSpriteStateData2
-	ld a, [H_CURRENTSPRITEOFFSET]
-	add $e
+	ldh a, [hCurrentSpriteOffset]
+	add SPRITESTATEDATA2_IMAGEBASEOFFSET
 	ld l, a
 	ld a, [hl] ; VRAM slot
 	dec a
 	swap a
 	ld b, a
 	ld hl, wSpriteStateData1
-	ld a, [H_CURRENTSPRITEOFFSET]
-	add $9
+	ldh a, [hCurrentSpriteOffset]
+	add SPRITESTATEDATA1_FACINGDIRECTION
 	ld l, a
 	ld a, [hl] ; facing direction
 	cp SPRITE_FACING_DOWN
@@ -819,42 +826,42 @@ AnimScriptedNPCMovement:
 .anim
 	add b
 	ld b, a
-	ld [hSpriteVRAMSlotAndFacing], a
+	ldh [hSpriteVRAMSlotAndFacing], a
 	call AdvanceScriptedNPCAnimFrameCounter
 	ld hl, wSpriteStateData1
-	ld a, [H_CURRENTSPRITEOFFSET]
-	add $2
+	ldh a, [hCurrentSpriteOffset]
+	add SPRITESTATEDATA1_IMAGEINDEX
 	ld l, a
-	ld a, [hSpriteVRAMSlotAndFacing]
+	ldh a, [hSpriteVRAMSlotAndFacing]
 	ld b, a
-	ld a, [hSpriteAnimFrameCounter]
+	ldh a, [hSpriteAnimFrameCounter]
 	add b
 	ld [hl], a
 	ret
 
 AdvanceScriptedNPCAnimFrameCounter:
 	call Func_5274
-	ld h, wSpriteStateData1 / $100
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ld h, HIGH(wSpriteStateData1)
+	ldh a, [hCurrentSpriteOffset]
 	add $8
 	ld l, a
 	ld a, [hl] ; intra-animation frame counter
 	and $3
-	ld [hSpriteAnimFrameCounter], a
+	ldh [hSpriteAnimFrameCounter], a
 	ret
 
 Func_5274:
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	add $7
 	ld l, a
-	ld h, wSpriteStateData1 / $100
-	ld a, [hl]                       ; c1x7 (counter until next walk animation frame)
+	ld h, HIGH(wSpriteStateData1)
+	ld a, [hl]                       ; x#SPRITESTATEDATA1_INTRAANIMFRAMECOUNTER
 	inc a
 	and $3
-	ld [hl], a                       ; c1x7 += 1
-	ret nz           	             ; c1x7 = 0
+	ld [hl], a                       ; [x#SPRITESTATEDATA1_INTRAANIMFRAMECOUNTER]++
+	ret nz
 	inc l
-	ld a, [hl]                       ; c1x8 (walk animation frame)
+	ld a, [hl]                       ; x#SPRITESTATEDATA1_ANIMFRAMECOUNTER
 	inc a
 	and $3
 	ld [hl], a                       ; advance to next animation frame every 4 ticks (16 ticks total for one step)
@@ -924,7 +931,7 @@ Func_5288:
 .asm_52e6
 	call Func_5337
 	call Func_5349
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	ld l, a
 	ld [hl], $8
 	dec h
@@ -936,7 +943,7 @@ Func_5288:
 
 .asm_52fa
 	call Func_5337
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	ld l, a
 	ld [hl], $8
 	dec h
@@ -949,7 +956,7 @@ Func_5288:
 .asm_530b
 	call Func_5337
 	call Func_5349
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	ld l, a
 	ld [hl], $8
 	dec h
@@ -980,39 +987,39 @@ Func_5331:
 	ret
 
 Func_5337:
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	add $9
 	ld l, a
-	ld h, wSpriteStateData1 / $100
-	ld [hl], c          ; c1x9 (update facing direction)
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ld h, HIGH(wSpriteStateData1)
+	ld [hl], c          ; x#SPRITESTATEDATA1_FACINGDIRECTION
+	ldh a, [hCurrentSpriteOffset]
 	add $3
 	ld l, a
-	ld [hl], d          ; c1x3 (update Y movement delta)
+	ld [hl], d          ; x#SPRITESTATEDATA1_YSTEPVECTOR
 	inc l
 	inc l
-	ld [hl], e          ; c1x5 (update X movement delta)
+	ld [hl], e          ; x#SPRITESTATEDATA1_XSTEPVECTOR
 	ret
 
 Func_5349:
-	ld h, wSpriteStateData2 / $100
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ld h, HIGH(wSpriteStateData2)
+	ldh a, [hCurrentSpriteOffset]
 	add $4
 	ld l, a
-	ld a, [hl]          ; c2x4: Y position
+	ld a, [hl]          ; x#SPRITESTATEDATA2_MAPY
 	add d
 	ld [hli], a         ; update Y position
-	ld a, [hl]          ; c2x5: X position
+	ld a, [hl]          ; x#SPRITESTATEDATA2_MAPX
 	add e
 	ld [hl], a          ; update X position
 	ret
 
 Func_5357:
 	call Func_5274
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	add $3
 	ld l, a
-	ld h, wSpriteStateData1 / $100
+	ld h, HIGH(wSpriteStateData1)
 	ld a, [hli]
 	add a
 	ld b, a
@@ -1025,9 +1032,9 @@ Func_5357:
 	ld a, [hl]
 	add b
 	ld [hl], a
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	ld l, a
-	ld h, wSpriteStateData2 / $100
+	ld h, HIGH(wSpriteStateData2)
 	dec [hl]
 	ret nz
 	ld a, $6
@@ -1036,23 +1043,23 @@ Func_5357:
 	ld a, [hl]
 	cp $fe
 	jr nc, .asm_5386
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	inc a
 	ld l, a
-	ld h, wSpriteStateData1 / $100
+	ld h, HIGH(wSpriteStateData1)
 	ld [hl], $1
 	ret
 .asm_5386
 	call Random
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	add $8
 	ld l, a
-	ld h, wSpriteStateData2 / $100
-	ld a, [hRandomAdd]
+	ld h, HIGH(wSpriteStateData2)
+	ldh a, [hRandomAdd]
 	and $7f
 	ld [hl], a
 	dec h
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	inc a
 	ld l, a
 	ld [hl], $2
diff --git a/engine/overworld/npc_movement_2.asm b/engine/overworld/npc_movement_2.asm
index 93d1afce..2ced9da6 100755
--- a/engine/overworld/npc_movement_2.asm
+++ b/engine/overworld/npc_movement_2.asm
@@ -1,4 +1,4 @@
-FreezeEnemyTrainerSprite:
+FreezeEnemyTrainerSprite::
 	ld a, [wCurMap]
 	cp POKEMON_TOWER_7F
 	ret z ; the Rockets on Pokemon Tower 7F leave after battling, so don't freeze them
@@ -7,18 +7,18 @@ FreezeEnemyTrainerSprite:
 	ld b, a
 .loop
 	ld a, [hli]
-	cp $ff
+	cp -1
 	jr z, .notRival
 	cp b
 	ret z ; the rival leaves after battling, so don't freeze him
 	jr .loop
 .notRival
 	ld a, [wSpriteIndex]
-	ld [H_SPRITEINDEX], a
+	ldh [hSpriteIndex], a
 	jp SetSpriteMovementBytesToFF
 
 RivalIDs:
-	db OPP_SONY1
-	db OPP_SONY2
-	db OPP_SONY3
-	db $ff
+	db OPP_RIVAL1
+	db OPP_RIVAL2
+	db OPP_RIVAL3
+	db -1 ; end
diff --git a/engine/overworld/oaks_aide.asm b/engine/overworld/oaks_aide.asm
deleted file mode 100755
index f5068fda..00000000
--- a/engine/overworld/oaks_aide.asm
+++ /dev/null
@@ -1,71 +0,0 @@
-OaksAideScript:
-	ld hl, OaksAideHiText
-	call PrintText
-	call YesNoChoice
-	ld a, [wCurrentMenuItem]
-	and a
-	jr nz, .choseNo
-	ld hl, wPokedexOwned
-	ld b, wPokedexOwnedEnd - wPokedexOwned
-	call CountSetBits
-	ld a, [wNumSetBits]
-	ld [hOaksAideNumMonsOwned], a
-	ld b, a
-	ld a, [hOaksAideRequirement]
-	cp b
-	jr z, .giveItem
-	jr nc, .notEnoughOwnedMons
-.giveItem
-	ld hl, OaksAideHereYouGoText
-	call PrintText
-	ld a, [hOaksAideRewardItem]
-	ld b, a
-	ld c, 1
-	call GiveItem
-	jr nc, .bagFull
-	ld hl, OaksAideGotItemText
-	call PrintText
-	ld a, $1
-	jr .done
-.bagFull
-	ld hl, OaksAideNoRoomText
-	call PrintText
-	xor a
-	jr .done
-.notEnoughOwnedMons
-	ld hl, OaksAideUhOhText
-	call PrintText
-	ld a, $80
-	jr .done
-.choseNo
-	ld hl, OaksAideComeBackText
-	call PrintText
-	ld a, $ff
-.done
-	ld [hOaksAideResult], a
-	ret
-
-OaksAideHiText:
-	TX_FAR _OaksAideHiText
-	db "@"
-
-OaksAideUhOhText:
-	TX_FAR _OaksAideUhOhText
-	db "@"
-
-OaksAideComeBackText:
-	TX_FAR _OaksAideComeBackText
-	db "@"
-
-OaksAideHereYouGoText:
-	TX_FAR _OaksAideHereYouGoText
-	db "@"
-
-OaksAideGotItemText:
-	TX_FAR _OaksAideGotItemText
-	TX_SFX_ITEM_1
-	db "@"
-
-OaksAideNoRoomText:
-	TX_FAR _OaksAideNoRoomText
-	db "@"
diff --git a/engine/overworld/oam.asm b/engine/overworld/oam.asm
deleted file mode 100644
index 5a831327..00000000
--- a/engine/overworld/oam.asm
+++ /dev/null
@@ -1,232 +0,0 @@
-PrepareOAMData:
-; Determine OAM data for currently visible
-; sprites and write it to wOAMBuffer.
-; Yellow code has been changed to use registers more efficiently
-; as well as tweaking the code to show gbc palettes
-
-	ld a, [wUpdateSpritesEnabled]
-	dec a
-	jr z, .updateEnabled
-
-	cp -1
-	ret nz
-	ld [wUpdateSpritesEnabled], a
-	jp HideSprites
-
-.updateEnabled
-	xor a
-	ld [hOAMBufferOffset], a
-
-.spriteLoop
-	ld [hSpriteOffset2], a
-
-	ld e, a
-	ld d, wSpriteStateData1 / $100
-
-	ld a, [de] ; c1x0
-	and a
-	jp z, .nextSprite
-
-	inc e
-	inc e
-	ld a, [de] ; c1x2 (facing/anim)
-	ld [wd5cd], a
-	cp $ff ; off-screen (don't draw)
-	jr nz, .visible
-
-	call GetSpriteScreenXY
-	jr .nextSprite
-
-.visible
-	cp $a0 ; is the sprite unchanging like an item ball or boulder?
-	jr c, .usefacing
-
-; unchanging
-	ld a, $0
-	jr .next
-
-.usefacing
-	and $f
-
-.next
-; read the entry from the table
-	ld c, a
-	ld b, 0
-	ld hl, SpriteFacingAndAnimationTable
-	add hl, bc
-	add hl, bc
-	ld a, [hli]
-	ld h, [hl]
-	ld l, a
-; get sprite priority
-	push de
-	inc d
-	ld a, e
-	add $5
-	ld e, a
-	ld a, [de] ; c2x7
-	and $80
-	ld [hSpritePriority], a ; temp store sprite priority
-	pop de
-
-
-	call GetSpriteScreenXY
-
-	ld a, [hOAMBufferOffset]
-	add [hl]
-	cp $a0
-	jr z, .hidden
-	jr nc, .asm_4a41
-.hidden
-	call Func_4a7b
-	ld [wd5cd], a
-	ld a, [hOAMBufferOffset]
-
-	ld e, a
-	ld d, wOAMBuffer / $100
-
-.tileLoop
-	ld a, [hli]
-	ld c, a
-.loop
-	ld a, [hSpriteScreenY]   ; temp for sprite Y position
-	add $10                  ; Y=16 is top of screen (Y=0 is invisible)
-	add [hl]                 ; add Y offset from table
-	ld [de], a               ; write new sprite OAM Y position
-	inc hl
-	inc e
-	ld a, [hSpriteScreenX]   ; temp for sprite X position
-	add $8                   ; X=8 is left of screen (X=0 is invisible)
-	add [hl]                 ; add X offset from table
-	ld [de], a
-	inc hl
-	inc e
-	ld a, [wd5cd]
-	add [hl]
-	cp $80
-	jr c, .asm_4a1c
-	ld b, a
-	ld a, [$fffc]
-	add b
-.asm_4a1c
-	ld [de], a ; tile id
-	inc hl
-	inc e
-	ld a, [hl]
-	bit 1, a ; is the tile allowed to set the sprite priority bit?
-	jr z, .skipPriority
-	ld a, [hSpritePriority]
-	or [hl]
-.skipPriority
-	and $f0
-	bit 4, a ; OBP0 or OBP1
-	jr z, .spriteusesOBP0
-	or %100 ; palettes 4-7 are OBP1
-.spriteusesOBP0
-	ld [de], a
-	inc hl
-	inc e
-	dec c
-	jr nz, .loop
-
-	ld a, e
-	ld [hOAMBufferOffset], a
-.nextSprite
-	ld a, [hSpriteOffset2]
-	add $10
-	cp $100 % $100
-	jp nz, .spriteLoop
-
-	; Clear unused OAM.
-.asm_4a41
-	ld a, [wd736]
-	bit 6, a ; jumping down ledge or fishing animation?
-	ld c, $a0
-	jr z, .clear
-
-; Don't clear the last 4 entries because they are used for the shadow in the
-; jumping down ledge animation and the rod in the fishing animation.
-	ld c, $90
-
-.clear
-	ld a, [hOAMBufferOffset]
-	cp c
-	ret nc
-	ld l, a
-	ld h, wOAMBuffer / $100
-	ld a, c
-	ld de, $4 ; entry size
-	ld b, $a0
-.clearLoop
-	ld [hl], b
-	add hl, de
-	cp l
-	jr nz, .clearLoop
-	ret
-
-GetSpriteScreenXY:
-	inc e
-	inc e
-	ld a, [de] ; c1x4
-	ld [hSpriteScreenY], a
-	inc e
-	inc e
-	ld a, [de] ; c1x6
-	ld [hSpriteScreenX], a
-	ld a, 4
-	add e
-	ld e, a
-	ld a, [hSpriteScreenY]
-	add 4
-	and $f0
-	ld [de], a ; c1xa (y)
-	inc e
-	ld a, [hSpriteScreenX]
-	and $f0
-	ld [de], a  ; c1xb (x)
-	ret
-
-Func_4a7b:
-	push bc
-	ld a, [wd5cd]            ; temp copy of c1x2
-	swap a                   ; high nybble determines sprite used (0 is always player sprite, next are some npcs)
-	and $f
-
-	; Sprites $a and $b have one face (and therefore 4 tiles instead of 12).
-	; As a result, sprite $b's tile offset is less than normal.
-	cp $b
-	jr nz, .notFourTileSprite
-	ld a, $a * 12 + 4 ; $7c
-	jr .done
-
-.notFourTileSprite
-	; a *= 12
-	add a
-	add a
-	ld c, a
-	add a
-	add c
-.done
-	pop bc
-	ret
-
-INCLUDE "engine/oam_dma.asm"
-
-_IsTilePassable::
-	ld hl,wTilesetCollisionPtr ; pointer to list of passable tiles
-	ld a,[hli]
-	ld h,[hl]
-	ld l,a ; hl now points to passable tiles
-.loop
-	ld a,[hli]
-	cp a,$ff
-	jr z,.tileNotPassable
-	cp c
-	jr nz,.loop
-	xor a
-	ret
-.tileNotPassable
-	scf
-	ret
-
-INCLUDE "data/collision.asm" ; probably
diff --git a/engine/overworld/pathfinding.asm b/engine/overworld/pathfinding.asm
new file mode 100644
index 00000000..a824d337
--- /dev/null
+++ b/engine/overworld/pathfinding.asm
@@ -0,0 +1,201 @@
+FindPathToPlayer:
+	xor a
+	ld hl, hFindPathNumSteps
+	ld [hli], a ; hFindPathNumSteps
+	ld [hli], a ; hFindPathFlags
+	ld [hli], a ; hFindPathYProgress
+	ld [hl], a  ; hFindPathXProgress
+	ld hl, wNPCMovementDirections2
+	ld de, $0
+.loop
+	ldh a, [hFindPathYProgress]
+	ld b, a
+	ldh a, [hNPCPlayerYDistance] ; Y distance in steps
+	call CalcDifference
+	ld d, a
+	and a
+	jr nz, .asm_f76a
+	ldh a, [hFindPathFlags]
+	set 0, a ; current end of path matches the player's Y coordinate
+	ldh [hFindPathFlags], a
+.asm_f76a
+	ldh a, [hFindPathXProgress]
+	ld b, a
+	ldh a, [hNPCPlayerXDistance] ; X distance in steps
+	call CalcDifference
+	ld e, a
+	and a
+	jr nz, .asm_f77c
+	ldh a, [hFindPathFlags]
+	set 1, a ; current end of path matches the player's X coordinate
+	ldh [hFindPathFlags], a
+.asm_f77c
+	ldh a, [hFindPathFlags]
+	cp $3 ; has the end of the path reached the player's position?
+	jr z, .done
+; Compare whether the X distance between the player and the current of the path
+; is greater or if the Y distance is. Then, try to reduce whichever is greater.
+	ld a, e
+	cp d
+	jr c, .yDistanceGreater
+; x distance is greater
+	ldh a, [hNPCPlayerRelativePosFlags]
+	bit 1, a
+	jr nz, .playerIsLeftOfNPC
+	ld d, NPC_MOVEMENT_RIGHT
+	jr .next1
+.playerIsLeftOfNPC
+	ld d, NPC_MOVEMENT_LEFT
+.next1
+	ldh a, [hFindPathXProgress]
+	add 1
+	ldh [hFindPathXProgress], a
+	jr .storeDirection
+.yDistanceGreater
+	ldh a, [hNPCPlayerRelativePosFlags]
+	bit 0, a
+	jr nz, .playerIsAboveNPC
+	ld d, NPC_MOVEMENT_DOWN
+	jr .next2
+.playerIsAboveNPC
+	ld d, NPC_MOVEMENT_UP
+.next2
+	ldh a, [hFindPathYProgress]
+	add 1
+	ldh [hFindPathYProgress], a
+.storeDirection
+	ld a, d
+	ld [hli], a
+	ldh a, [hFindPathNumSteps]
+	inc a
+	ldh [hFindPathNumSteps], a
+	jp .loop
+.done
+	ld [hl], $ff
+	ret
+
+CalcPositionOfPlayerRelativeToNPC:
+	xor a
+	ldh [hNPCPlayerRelativePosFlags], a
+	ld a, [wSpritePlayerStateData1YPixels]
+	ld d, a
+	ld a, [wSpritePlayerStateData1XPixels]
+	ld e, a
+	ld hl, wSpriteStateData1
+	ldh a, [hNPCSpriteOffset]
+	add l
+	add SPRITESTATEDATA1_YPIXELS
+	ld l, a
+	jr nc, .noCarry
+	inc h
+.noCarry
+	ld a, d
+	ld b, a
+	ld a, [hli] ; NPC sprite screen Y position in pixels
+	call CalcDifference
+	jr nc, .NPCSouthOfOrAlignedWithPlayer
+.NPCNorthOfPlayer
+	push hl
+	ld hl, hNPCPlayerRelativePosFlags
+	bit 0, [hl]
+	set 0, [hl]
+	pop hl
+	jr .divideYDistance
+.NPCSouthOfOrAlignedWithPlayer
+	push hl
+	ld hl, hNPCPlayerRelativePosFlags
+	bit 0, [hl]
+	res 0, [hl]
+	pop hl
+.divideYDistance
+	push hl
+	ld hl, hDividend2
+	ld [hli], a
+	ld a, 16
+	ld [hli], a
+	call DivideBytes ; divide Y absolute distance by 16
+	ld a, [hl] ; quotient
+	ldh [hNPCPlayerYDistance], a
+	pop hl
+	inc hl
+	ld b, e
+	ld a, [hl] ; NPC sprite screen X position in pixels
+	call CalcDifference
+	jr nc, .NPCEastOfOrAlignedWithPlayer
+.NPCWestOfPlayer
+	push hl
+	ld hl, hNPCPlayerRelativePosFlags
+	bit 1, [hl]
+	set 1, [hl]
+	pop hl
+	jr .divideXDistance
+.NPCEastOfOrAlignedWithPlayer
+	push hl
+	ld hl, hNPCPlayerRelativePosFlags
+	bit 1, [hl]
+	res 1, [hl]
+	pop hl
+.divideXDistance
+	ldh [hDividend2], a
+	ld a, 16
+	ldh [hDivisor2], a
+	call DivideBytes ; divide X absolute distance by 16
+	ldh a, [hQuotient2]
+	ldh [hNPCPlayerXDistance], a
+	ldh a, [hNPCPlayerRelativePosPerspective]
+	and a
+	ret z
+	ldh a, [hNPCPlayerRelativePosFlags]
+	cpl
+	and $3
+	ldh [hNPCPlayerRelativePosFlags], a
+	ret
+
+ConvertNPCMovementDirectionsToJoypadMasks:
+	ldh a, [hNPCMovementDirections2Index]
+	ld [wNPCMovementDirections2Index], a
+	dec a
+	ld de, wSimulatedJoypadStatesEnd
+	ld hl, wNPCMovementDirections2
+	add l
+	ld l, a
+	jr nc, .loop
+	inc h
+.loop
+	ld a, [hld]
+	call ConvertNPCMovementDirectionToJoypadMask
+	ld [de], a
+	inc de
+	ldh a, [hNPCMovementDirections2Index]
+	dec a
+	ldh [hNPCMovementDirections2Index], a
+	jr nz, .loop
+	ret
+
+ConvertNPCMovementDirectionToJoypadMask:
+	push hl
+	ld b, a
+	ld hl, NPCMovementDirectionsToJoypadMasksTable
+.loop
+	ld a, [hli]
+	cp $ff
+	jr z, .done
+	cp b
+	jr z, .loadJoypadMask
+	inc hl
+	jr .loop
+.loadJoypadMask
+	ld a, [hl]
+.done
+	pop hl
+	ret
+
+NPCMovementDirectionsToJoypadMasksTable:
+	db NPC_MOVEMENT_UP, D_UP
+	db NPC_MOVEMENT_DOWN, D_DOWN
+	db NPC_MOVEMENT_LEFT, D_LEFT
+	db NPC_MOVEMENT_RIGHT, D_RIGHT
+	db $ff
+
+; unreferenced
+	ret
diff --git a/engine/overworld/pewter_guys.asm b/engine/overworld/pewter_guys.asm
deleted file mode 100755
index 532fa4bf..00000000
--- a/engine/overworld/pewter_guys.asm
+++ /dev/null
@@ -1,102 +0,0 @@
-PewterGuys:
-	ld hl, wSimulatedJoypadStatesEnd
-	ld a, [wSimulatedJoypadStatesIndex]
-	dec a ; this decrement causes it to overwrite the last byte before $FF in the list
-	ld [wSimulatedJoypadStatesIndex], a
-	ld d, 0
-	ld e, a
-	add hl, de
-	ld d, h
-	ld e, l
-	ld hl, PointerTable_37ce6
-	ld a, [wWhichPewterGuy]
-	add a
-	ld b, 0
-	ld c, a
-	add hl, bc
-	ld a, [hli]
-	ld h, [hl]
-	ld l, a
-	ld a, [wYCoord]
-	ld b, a
-	ld a, [wXCoord]
-	ld c, a
-.findMatchingCoordsLoop
-	ld a, [hli]
-	cp b
-	jr nz, .nextEntry1
-	ld a, [hli]
-	cp c
-	jr nz, .nextEntry2
-	ld a, [hli]
-	ld h, [hl]
-	ld l, a
-.copyMovementDataLoop
-	ld a, [hli]
-	cp $ff
-	ret z
-	ld [de], a
-	inc de
-	ld a, [wSimulatedJoypadStatesIndex]
-	inc a
-	ld [wSimulatedJoypadStatesIndex], a
-	jr .copyMovementDataLoop
-.nextEntry1
-	inc hl
-.nextEntry2
-	inc hl
-	inc hl
-	jr .findMatchingCoordsLoop
-
-PointerTable_37ce6:
-	dw PewterMuseumGuyCoords
-	dw PewterGymGuyCoords
-
-; these are the four coordinates of the spaces below, above, to the left and
-; to the right of the museum guy, and pointers to different movements for
-; the player to make to get positioned before the main movement.
-PewterMuseumGuyCoords:
-	db 18, 27
-	dw .down
-	db 16, 27
-	dw .up
-	db 17, 26
-	dw .left
-	db 17, 28
-	dw .right
-
-.down
-	db D_UP, D_UP, $ff
-.up
-	db D_RIGHT, D_LEFT, $ff
-.left
-	db D_UP, D_RIGHT, $ff
-.right
-	db D_UP, D_LEFT, $ff
-
-; these are the five coordinates which trigger the gym guy and pointers to
-; different movements for the player to make to get positioned before the
-; main movement
-; $00 is a pause
-PewterGymGuyCoords:
-	db 16, 34
-	dw .one
-	db 17, 35
-	dw .two
-	db 18, 37
-	dw .three
-	db 19, 37
-	dw .four
-	db 17, 36
-	dw .five
-
-.one
-	db D_LEFT, D_DOWN, D_DOWN, D_RIGHT, $ff
-.two
-	db D_LEFT, D_DOWN, D_RIGHT, D_LEFT, $ff
-.three
-	db D_LEFT, D_LEFT, D_LEFT, $00, $00, $00, $00, $00, $00, $00, $00, $ff
-.four
-	db D_LEFT, D_LEFT, D_UP, D_LEFT, $ff
-.five
-	db D_LEFT, D_DOWN, D_LEFT, $00, $00, $00, $00, $00, $00, $00, $00, $ff
diff --git a/engine/overworld/player_animations.asm b/engine/overworld/player_animations.asm
index d4ecec53..5056c0b2 100755
--- a/engine/overworld/player_animations.asm
+++ b/engine/overworld/player_animations.asm
@@ -1,7 +1,7 @@
-EnterMapAnim:
+EnterMapAnim::
 	call InitFacingDirectionList
 	ld a, $ec
-	ld [wSpriteStateData1 + 4], a ; player's sprite Y screen position
+	ld [wSpritePlayerStateData1YPixels], a
 	call Delay3
 	push hl
 	call GBFadeInFromWhite
@@ -94,7 +94,7 @@ PlayerSpinWhileMovingDown:
 	jp PlayerSpinWhileMovingUpOrDown
 
 
-_LeaveMapAnim:
+_LeaveMapAnim::
 	call Func_1510
 	call InitFacingDirectionList
 	call IsPlayerStandingOnWarpPadOrHole
@@ -232,19 +232,19 @@ DoFlyAnimation:
 	ld a, [wFlyAnimBirdSpriteImageIndex]
 	xor $1 ; make the bird flap its wings
 	ld [wFlyAnimBirdSpriteImageIndex], a
-	ld [wSpriteStateData1 + 2], a
+	ld [wSpritePlayerStateData1ImageIndex], a
 	call Delay3
 	ld a, [wFlyAnimUsingCoordList]
 	cp $ff
 	jr z, .skipCopyingCoords ; if the bird is flapping its wings in place
-	ld hl, wSpriteStateData1 + 4
+	ld hl, wSpritePlayerStateData1YPixels
 	ld a, [de]
 	inc de
-	ld [hli], a
+	ld [hli], a ; y
 	inc hl
 	ld a, [de]
 	inc de
-	ld [hl], a
+	ld [hl], a ; x
 .skipCopyingCoords
 	ld a, [wFlyAnimCounter]
 	dec a
@@ -258,22 +258,22 @@ LoadBirdSpriteGraphics:
 	ld c, $c
 	ld hl, vNPCSprites
 	call CopyVideoData
-	ld de, BirdSprite + $c0 ; moving animation sprite
+	ld de, BirdSprite tile 12 ; moving animation sprite
 	ld b, BANK(BirdSprite)
-	ld c, $0c
+	ld c, 12
 	ld hl, vNPCSprites2
 	jp CopyVideoData
 
 InitFacingDirectionList:
-	ld a, [wSpriteStateData1 + 2] ; player's sprite facing direction (image index is locked to standing images)
+	ld a, [wSpritePlayerStateData1ImageIndex] ; (image index is locked to standing images)
 	ld [wSavedPlayerFacingDirection], a
-	ld a, [wSpriteStateData1 + 4] ; player's sprite Y screen position
+	ld a, [wSpritePlayerStateData1YPixels]
 	ld [wSavedPlayerScreenY], a
 	ld hl, PlayerSpinningFacingOrder
 	ld de, wFacingDirectionList
 	ld bc, 4
 	call CopyData
-	ld a, [wSpriteStateData1 + 2] ; player's sprite facing direction (image index is locked to standing images)
+	ld a, [wSpritePlayerStateData1ImageIndex] ; (image index is locked to standing images)
 	ld hl, wFacingDirectionList
 ; find the place in the list that matches the current facing direction
 .loop
@@ -291,7 +291,7 @@ PlayerSpinningFacingOrder:
 SpinPlayerSprite:
 ; copy the current value from the list into the sprite data and rotate the list
 	ld a, [hl]
-	ld [wSpriteStateData1 + 2], a ; player's sprite facing direction (image index is locked to standing images)
+	ld [wSpritePlayerStateData1ImageIndex], a ; (image index is locked to standing images)
 	push hl
 	ld hl, wFacingDirectionList
 	ld de, wFacingDirectionList - 1
@@ -327,9 +327,9 @@ PlayerSpinWhileMovingUpOrDown:
 	call SpinPlayerSprite
 	ld a, [wPlayerSpinWhileMovingUpOrDownAnimDeltaY]
 	ld c, a
-	ld a, [wSpriteStateData1 + 4] ; player's sprite Y screen position
+	ld a, [wSpritePlayerStateData1YPixels]
 	add c
-	ld [wSpriteStateData1 + 4], a
+	ld [wSpritePlayerStateData1YPixels], a
 	ld c, a
 	ld a, [wPlayerSpinWhileMovingUpOrDownAnimMaxY]
 	cp c
@@ -341,9 +341,9 @@ PlayerSpinWhileMovingUpOrDown:
 
 RestoreFacingDirectionAndYScreenPos:
 	ld a, [wSavedPlayerScreenY]
-	ld [wSpriteStateData1 + 4], a
+	ld [wSpritePlayerStateData1YPixels], a
 	ld a, [wSavedPlayerFacingDirection]
-	ld [wSpriteStateData1 + 2], a
+	ld [wSpritePlayerStateData1ImageIndex], a ; (image index is locked to standing images)
 	ret
 
 ; if SGB, 2 frames, else 3 frames
@@ -354,9 +354,9 @@ GetPlayerTeleportAnimFrameDelay:
 	inc a
 	ret
 
-IsPlayerStandingOnWarpPadOrHole:
+IsPlayerStandingOnWarpPadOrHole::
 	ld b, 0
-	ld hl, .warpPadAndHoleData
+	ld hl, WarpPadAndHoleData
 	ld a, [wCurMapTileset]
 	ld c, a
 .loop
@@ -365,7 +365,7 @@ IsPlayerStandingOnWarpPadOrHole:
 	jr z, .done
 	cp c
 	jr nz, .nextEntry
-	aCoord 8, 9
+	lda_coord 8, 9
 	cp [hl]
 	jr z, .foundMatch
 .nextEntry
@@ -380,13 +380,7 @@ IsPlayerStandingOnWarpPadOrHole:
 	ld [wStandingOnWarpPadOrHole], a
 	ret
 
-; format: db tileset id, tile id, value to be put in [wStandingOnWarpPadOrHole]
-.warpPadAndHoleData:
-	db FACILITY, $20, 1 ; warp pad
-	db FACILITY, $11, 2 ; hole
-	db CAVERN,   $22, 2 ; hole
-	db INTERIOR, $55, 1 ; warp pad
-	db $FF
+INCLUDE "data/tilesets/warp_pad_hole_tile_ids.asm"
 
 FishingAnim:
 	ld c, 10
@@ -396,12 +390,12 @@ FishingAnim:
 	ld hl, vNPCSprites
 	ld de, RedSprite
 	ld b, BANK(RedSprite)
-	ld c, $c
+	ld c, 12
 	call CopyVideoData
 	ld a, $4
 	ld hl, RedFishingTiles
 	call LoadAnimSpriteGfx
-	ld a, [wSpriteStateData1 + 2]
+	ld a, [wSpritePlayerStateData1ImageIndex]
 	ld c, a
 	ld b, $0
 	ld hl, FishingRodOAM
@@ -424,7 +418,7 @@ FishingAnim:
 ; shake the player's sprite vertically
 	ld b, 10
 .loop
-	ld hl, wSpriteStateData1 + 4 ; player's sprite Y screen position
+	ld hl, wSpritePlayerStateData1YPixels
 	call .ShakePlayerSprite
 	ld hl, wOAMBuffer + $9c
 	call .ShakePlayerSprite
@@ -434,7 +428,7 @@ FishingAnim:
 
 ; If the player is facing up, hide the fishing rod so it doesn't overlap with
 ; the exclamation bubble that will be shown next.
-	ld a, [wSpriteStateData1 + 2] ; player's sprite facing direction
+	ld a, [wSpritePlayerStateData1ImageIndex] ; (image index is locked to standing images)
 	cp SPRITE_FACING_UP
 	jr nz, .skipHidingFishingRod
 	ld a, $a0
@@ -448,7 +442,7 @@ FishingAnim:
 	predef EmotionBubble
 
 ; If the player is facing up, unhide the fishing rod.
-	ld a, [wSpriteStateData1 + 2] ; player's sprite facing direction
+	ld a, [wSpritePlayerStateData1ImageIndex] ; (image index is locked to standing images)
 	cp SPRITE_FACING_UP
 	jr nz, .skipUnhidingFishingRod
 	ld a, $44
@@ -471,46 +465,38 @@ FishingAnim:
 	ret
 
 NoNibbleText:
-	TX_FAR _NoNibbleText
-	db "@"
+	text_far _NoNibbleText
+	text_end
 
 NothingHereText:
-	TX_FAR _NothingHereText
-	db "@"
+	text_far _NothingHereText
+	text_end
 
 ItsABiteText:
-	TX_FAR _ItsABiteText
-	db "@"
+	text_far _ItsABiteText
+	text_end
 
 FishingRodOAM:
 ; specifies how the fishing rod should be drawn on the screen
-; first byte = screen y coordinate
-; second byte = screen x coordinate
-; third byte = tile number
-; fourth byte = sprite properties
-	db $5B, $4C, $FD, $00 ; player facing down
-	db $44, $4C, $FD, $00 ; player facing up
-	db $50, $40, $FE, $00 ; player facing left
-	db $50, $58, $FE, $20 ; player facing right ($20 means "horizontally flip the tile")
+	dbsprite  9, 11,  4,  3, $fd, 0         ; down
+	dbsprite  9,  8,  4,  4, $fd, 0         ; up
+	dbsprite  8, 10,  0,  0, $fe, 0         ; left
+	dbsprite 11, 10,  0,  0, $fe, OAM_HFLIP ; right
+
+fishing_gfx: MACRO
+	dw \1
+	db \2
+	db BANK(\1)
+	dw vNPCSprites tile \3
+ENDM
 
 RedFishingTiles:
-	dw RedFishingTilesFront
-	db 2, BANK(RedFishingTilesFront)
-	dw vNPCSprites + $20
-
-	dw RedFishingTilesBack
-	db 2, BANK(RedFishingTilesBack)
-	dw vNPCSprites + $60
-
-	dw RedFishingTilesSide
-	db 2, BANK(RedFishingTilesSide)
-	dw vNPCSprites + $a0
-
-	dw RedFishingRodTiles
-	db 3, BANK(RedFishingRodTiles)
-	dw vNPCSprites2 + $7d0
+	fishing_gfx RedFishingTilesFront, 2, $02
+	fishing_gfx RedFishingTilesBack,  2, $06
+	fishing_gfx RedFishingTilesSide,  2, $0a
+	fishing_gfx RedFishingRodTiles,   3, $fd
 
-_HandleMidJump:
+_HandleMidJump::
 	ld a, [wPlayerJumpingYScreenCoordsIndex]
 	ld c, a
 	inc a
@@ -521,7 +507,7 @@ _HandleMidJump:
 	ld hl, PlayerJumpingYScreenCoords
 	add hl, bc
 	ld a, [hl]
-	ld [wSpriteStateData1 + 4], a ; player's sprite y coordinate
+	ld [wSpritePlayerStateData1YPixels], a
 	ret
 .finishedJump
 	ld a, [wWalkCounter]
@@ -530,9 +516,9 @@ _HandleMidJump:
 	call UpdateSprites
 	call Delay3
 	xor a
-	ld [hJoyHeld], a
-	ld [hJoyPressed], a
-	ld [hJoyReleased], a
+	ldh [hJoyHeld], a
+	ldh [hJoyPressed], a
+	ldh [hJoyReleased], a
 	ld [wPlayerJumpingYScreenCoordsIndex], a
 	ld hl, wd736
 	res 6, [hl] ; not jumping down a ledge any more
diff --git a/engine/overworld/player_state.asm b/engine/overworld/player_state.asm
index 8cbacc61..c966c128 100644
--- a/engine/overworld/player_state.asm
+++ b/engine/overworld/player_state.asm
@@ -1,5 +1,5 @@
 ; only used for setting bit 2 of wd736 upon entering a new map
-IsPlayerStandingOnWarp:
+IsPlayerStandingOnWarp::
 	ld a, [wNumberOfWarps]
 	and a
 	ret z
@@ -17,7 +17,7 @@ IsPlayerStandingOnWarp:
 	ld a, [hli] ; target warp
 	ld [wDestinationWarpID], a
 	ld a, [hl] ; target map
-	ld [hWarpDestinationMap], a
+	ldh [hWarpDestinationMap], a
 	ld hl, wd736
 	set 2, [hl] ; standing on warp flag
 	ret
@@ -31,7 +31,7 @@ IsPlayerStandingOnWarp:
 	jr nz, .loop
 	ret
 
-CheckForceBikeOrSurf:
+CheckForceBikeOrSurf::
 	ld hl, wd732
 	bit 5, [hl]
 	ret nz
@@ -84,13 +84,13 @@ CheckForceBikeOrSurf:
 	call ForceBikeOrSurf
 	ret
 
-INCLUDE "data/force_bike_surf.asm"
+INCLUDE "data/maps/force_bike_surf.asm"
 
-IsPlayerFacingEdgeOfMap:
+IsPlayerFacingEdgeOfMap::
 	push hl
 	push de
 	push bc
-	ld a, [wSpriteStateData1 + 9] ; player sprite's facing direction
+	ld a, [wSpritePlayerStateData1FacingDirection]
 	srl a
 	ld c, a
 	ld b, $0
@@ -152,19 +152,19 @@ IsPlayerFacingEdgeOfMap:
 	scf
 	ret
 
-IsWarpTileInFrontOfPlayer:
+IsWarpTileInFrontOfPlayer::
 	push hl
 	push de
 	push bc
 	call _GetTileAndCoordsInFrontOfPlayer
 	ld a, [wCurMap]
 	cp SS_ANNE_BOW
-	jr z, .ssAnne5
-	ld a, [wSpriteStateData1 + 9] ; player sprite's facing direction
+	jr z, IsSSAnneBowWarpTileInFrontOfPlayer
+	ld a, [wSpritePlayerStateData1FacingDirection]
 	srl a
 	ld c, a
 	ld b, 0
-	ld hl, .warpTileListPointers
+	ld hl, WarpTileListPointers
 	add hl, bc
 	ld a, [hli]
 	ld h, [hl]
@@ -178,39 +178,23 @@ IsWarpTileInFrontOfPlayer:
 	pop hl
 	ret
 
-.warpTileListPointers:
-	dw .facingDownWarpTiles
-	dw .facingUpWarpTiles
-	dw .facingLeftWarpTiles
-	dw .facingRightWarpTiles
+INCLUDE "data/tilesets/warp_carpet_tile_ids.asm"
 
-.facingDownWarpTiles
-	db $01,$12,$17,$3D,$04,$18,$33,$FF
-
-.facingUpWarpTiles
-	db $01,$5C,$FF
-
-.facingLeftWarpTiles
-	db $1A,$4B,$FF
-
-.facingRightWarpTiles
-	db $0F,$4E,$FF
-
-.ssAnne5
+IsSSAnneBowWarpTileInFrontOfPlayer:
 	ld a, [wTileInFrontOfPlayer]
 	cp $15
 	jr nz, .notSSAnne5Warp
 	scf
-	jr .done
+	jr IsWarpTileInFrontOfPlayer.done
 .notSSAnne5Warp
 	and a
-	jr .done
+	jr IsWarpTileInFrontOfPlayer.done
 
-IsPlayerStandingOnDoorTileOrWarpTile:
+IsPlayerStandingOnDoorTileOrWarpTile::
 	push hl
 	push de
 	push bc
-	callba IsPlayerStandingOnDoorTile
+	farcall IsPlayerStandingOnDoorTile
 	jr c, .done
 	ld a, [wCurMapTileset]
 	add a
@@ -222,7 +206,7 @@ IsPlayerStandingOnDoorTileOrWarpTile:
 	ld h, [hl]
 	ld l, a
 	ld de, $1
-	aCoord 8, 9
+	lda_coord 8, 9
 	call IsInArray
 	jr nc, .done
 	ld hl, wd736
@@ -233,35 +217,35 @@ IsPlayerStandingOnDoorTileOrWarpTile:
 	pop hl
 	ret
 
-INCLUDE "data/warp_tile_ids.asm"
+INCLUDE "data/tilesets/warp_tile_ids.asm"
 
-PrintSafariZoneSteps:
+PrintSafariZoneSteps::
 	ld a, [wCurMap]
 	cp SAFARI_ZONE_EAST
 	ret c
 	cp CERULEAN_CAVE_2F
 	ret nc
-	coord hl, 0, 0
+	hlcoord 0, 0
 	lb bc, 3, 7
 	call TextBoxBorder
-	coord hl, 1, 1
+	hlcoord 1, 1
 	ld de, wSafariSteps
 	lb bc, 2, 3
 	call PrintNumber
-	coord hl, 4, 1
+	hlcoord 4, 1
 	ld de, SafariSteps
 	call PlaceString
-	coord hl, 1, 3
+	hlcoord 1, 3
 	ld de, SafariBallText
 	call PlaceString
 	ld a, [wNumSafariBalls]
 	cp 10
 	jr nc, .numSafariBallsTwoDigits
-	coord hl, 5, 3
+	hlcoord 5, 3
 	ld a, " "
 	ld [hl], a
 .numSafariBallsTwoDigits
-	coord hl, 6, 3
+	hlcoord 6, 3
 	ld de, wNumSafariBalls
 	lb bc, 1, 2
 	jp PrintNumber
@@ -280,32 +264,32 @@ _GetTileAndCoordsInFrontOfPlayer:
 	ld d, a
 	ld a, [wXCoord]
 	ld e, a
-	ld a, [wSpriteStateData1 + 9] ; player's sprite facing direction
+	ld a, [wSpritePlayerStateData1FacingDirection]
 	and a ; cp SPRITE_FACING_DOWN
 	jr nz, .notFacingDown
 ; facing down
-	aCoord 8, 11
+	lda_coord 8, 11
 	inc d
 	jr .storeTile
 .notFacingDown
 	cp SPRITE_FACING_UP
 	jr nz, .notFacingUp
 ; facing up
-	aCoord 8, 7
+	lda_coord 8, 7
 	dec d
 	jr .storeTile
 .notFacingUp
 	cp SPRITE_FACING_LEFT
 	jr nz, .notFacingLeft
 ; facing left
-	aCoord 6, 9
+	lda_coord 6, 9
 	dec e
 	jr .storeTile
 .notFacingLeft
 	cp SPRITE_FACING_RIGHT
 	jr nz, .storeTile
 ; facing right
-	aCoord 10, 9
+	lda_coord 10, 9
 	inc e
 .storeTile
 	ld c, a
@@ -314,45 +298,45 @@ _GetTileAndCoordsInFrontOfPlayer:
 
 GetTileTwoStepsInFrontOfPlayer:
 	xor a
-	ld [$ffdb], a
+	ldh [hPlayerFacing], a
 	ld hl, wYCoord
 	ld a, [hli]
 	ld d, a
 	ld e, [hl]
-	ld a, [wSpriteStateData1 + 9] ; player's sprite facing direction
+	ld a, [wSpritePlayerStateData1FacingDirection]
 	and a ; cp SPRITE_FACING_DOWN
 	jr nz, .notFacingDown
 ; facing down
-	ld hl, $ffdb
+	ld hl, hPlayerFacing
 	set 0, [hl]
-	aCoord 8, 13
+	lda_coord 8, 13
 	inc d
 	jr .storeTile
 .notFacingDown
 	cp SPRITE_FACING_UP
 	jr nz, .notFacingUp
 ; facing up
-	ld hl, $ffdb
+	ld hl, hPlayerFacing
 	set 1, [hl]
-	aCoord 8, 5
+	lda_coord 8, 5
 	dec d
 	jr .storeTile
 .notFacingUp
 	cp SPRITE_FACING_LEFT
 	jr nz, .notFacingLeft
 ; facing left
-	ld hl, $ffdb
+	ld hl, hPlayerFacing
 	set 2, [hl]
-	aCoord 4, 9
+	lda_coord 4, 9
 	dec e
 	jr .storeTile
 .notFacingLeft
 	cp SPRITE_FACING_RIGHT
 	jr nz, .storeTile
 ; facing right
-	ld hl, $ffdb
+	ld hl, hPlayerFacing
 	set 3, [hl]
-	aCoord 12, 9
+	lda_coord 12, 9
 	inc e
 .storeTile
 	ld c, a
@@ -384,36 +368,36 @@ CheckForBoulderCollisionWithSprites:
 	swap a
 	ld d, 0
 	ld e, a
-	ld hl, wSpriteStateData2 + $14
+	ld hl, wSprite01StateData2MapY
 	add hl, de
 	ld a, [hli] ; map Y position
-	ld [$ffdc], a
+	ldh [hPlayerYCoord], a
 	ld a, [hl] ; map X position
-	ld [$ffdd], a
+	ldh [hPlayerXCoord], a
 	ld a, [wNumSprites]
 	ld c, a
 	ld de, $f
-	ld hl, wSpriteStateData2 + $14
-	ld a, [$ffdb]
+	ld hl, wSprite01StateData2MapY
+	ldh a, [hPlayerFacing]
 	and $3 ; facing up or down?
 	jr z, .pushingHorizontallyLoop
 .pushingVerticallyLoop
 	inc hl
-	ld a, [$ffdd]
+	ldh a, [hPlayerXCoord]
 	cp [hl]
 	jr nz, .nextSprite1 ; if X coordinates don't match
 	dec hl
 	ld a, [hli]
 	ld b, a
-	ld a, [$ffdb]
+	ldh a, [hPlayerFacing]
 	rrca
 	jr c, .pushingDown
 ; pushing up
-	ld a, [$ffdc]
+	ldh a, [hPlayerYCoord]
 	dec a
 	jr .compareYCoords
 .pushingDown
-	ld a, [$ffdc]
+	ldh a, [hPlayerYCoord]
 	inc a
 .compareYCoords
 	cp b
@@ -426,19 +410,19 @@ CheckForBoulderCollisionWithSprites:
 .pushingHorizontallyLoop
 	ld a, [hli]
 	ld b, a
-	ld a, [$ffdc]
+	ldh a, [hPlayerYCoord]
 	cp b
 	jr nz, .nextSprite2
 	ld b, [hl]
-	ld a, [$ffdb]
+	ldh a, [hPlayerFacing]
 	bit 2, a
 	jr nz, .pushingLeft
 ; pushing right
-	ld a, [$ffdd]
+	ldh a, [hPlayerXCoord]
 	inc a
 	jr .compareXCoords
 .pushingLeft
-	ld a, [$ffdd]
+	ldh a, [hPlayerXCoord]
 	dec a
 .compareXCoords
 	cp b
diff --git a/engine/overworld/poison.asm b/engine/overworld/poison.asm
deleted file mode 100644
index 03fb8a65..00000000
--- a/engine/overworld/poison.asm
+++ /dev/null
@@ -1,151 +0,0 @@
-ApplyOutOfBattlePoisonDamage:
-	ld a, [wd730]
-	add a
-	jp c, .noBlackOut ; no black out if joypad states are being simulated
-	ld a, [wd492]
-	bit 7, a
-	jp nz, .noBlackOut
-	ld a, [wd72e]
-	bit 6, a
-	jp nz, .noBlackOut
-	ld a, [wPartyCount]
-	and a
-	jp z, .noBlackOut
-	call IncrementDayCareMonExp
-	call Func_c4c7
-	ld a, [wStepCounter]
-	and $3 ; is the counter a multiple of 4?
-	jp nz, .skipPoisonEffectAndSound ; only apply poison damage every fourth step
-	ld [wWhichPokemon], a
-	ld hl, wPartyMon1Status
-	ld de, wPartySpecies
-.applyDamageLoop
-	ld a, [hl]
-	and (1 << PSN)
-	jr z, .nextMon2 ; not poisoned
-	dec hl
-	dec hl
-	ld a, [hld]
-	ld b, a
-	ld a, [hli]
-	or b
-	jr z, .nextMon ; already fainted
-; subtract 1 from HP
-	ld a, [hl]
-	dec a
-	ld [hld], a
-	inc a
-	jr nz, .noBorrow
-; borrow 1 from upper byte of HP
-	dec [hl]
-	inc hl
-	jr .nextMon
-.noBorrow
-	ld a, [hli]
-	or [hl]
-	jr nz, .nextMon ; didn't faint from damage
-; the mon fainted from the damage
-	push hl
-	inc hl
-	inc hl
-	ld [hl], a
-	ld a, [de]
-	ld [wd11e], a
-	push de
-	ld a, [wWhichPokemon]
-	ld hl, wPartyMonNicks
-	call GetPartyMonName
-	xor a
-	ld [wJoyIgnore], a
-	call EnableAutoTextBoxDrawing
-	ld a, TEXT_MON_FAINTED
-	ld [hSpriteIndexOrTextID], a
-	call DisplayTextID
-	callab IsThisPartymonStarterPikachu_Party
-	jr nc, .curMonNotPlayerPikachu
-	ld e, $3
-	callab PlayPikachuSoundClip
-	calladb_ModifyPikachuHappiness PIKAHAPPY_PSNFNT
-.curMonNotPlayerPikachu
-	pop de
-	pop hl
-.nextMon
-	inc hl
-	inc hl
-.nextMon2
-	inc de
-	ld a, [de]
-	inc a
-	jr z, .applyDamageLoopDone
-	ld bc, wPartyMon2 - wPartyMon1
-	add hl, bc
-	push hl
-	ld hl, wWhichPokemon
-	inc [hl]
-	pop hl
-	jr .applyDamageLoop
-.applyDamageLoopDone
-	ld hl, wPartyMon1Status
-	ld a, [wPartyCount]
-	ld d, a
-	ld e, 0
-.countPoisonedLoop
-	ld a, [hl]
-	and (1 << PSN)
-	or e
-	ld e, a
-	ld bc, wPartyMon2 - wPartyMon1
-	add hl, bc
-	dec d
-	jr nz, .countPoisonedLoop
-	ld a, e
-	and a ; are any party members poisoned?
-	jr z, .skipPoisonEffectAndSound
-	ld b, $2
-	predef ChangeBGPalColor0_4Frames ; change BG white to dark grey for 4 frames
-	ld a, SFX_POISONED
-	call PlaySound
-.skipPoisonEffectAndSound
-	predef AnyPartyAlive
-	ld a, d
-	and a
-	jr nz, .noBlackOut
-	call EnableAutoTextBoxDrawing
-	ld a, TEXT_BLACKED_OUT
-	ld [hSpriteIndexOrTextID], a
-	call DisplayTextID
-	ld hl, wd72e
-	set 5, [hl]
-	ld a, $ff
-	jr .done
-.noBlackOut
-	xor a
-.done
-	ld [wOutOfBattleBlackout], a
-	ret
-
-Func_c4c7:
-	ld a, [wStepCounter]
-	and a
-	jr nz, .asm_c4de
-	call Random
-	and $1
-	jr z, .asm_c4de
-	calladb_ModifyPikachuHappiness $6
-.asm_c4de
-	ld hl, wPikachuMood
-	ld a, [hl]
-	cp $80
-	jr z, .asm_c4ef
-	jr c, .asm_c4ea
-	dec a
-	dec a
-.asm_c4ea
-	inc a
-	ld [hl], a
-	cp $80
-	ret nz
-.asm_c4ef
-	xor a
-	ld [wd49c], a
-	ret
diff --git a/engine/overworld/pokecenter.asm b/engine/overworld/pokecenter.asm
deleted file mode 100755
index cf0159f9..00000000
--- a/engine/overworld/pokecenter.asm
+++ /dev/null
@@ -1,149 +0,0 @@
-DisplayPokemonCenterDialogue_:
-	ld a, [wCurMap]
-	cp PEWTER_POKECENTER
-	jr nz, .regularCenter
-	call CheckPikachuFollowingPlayer
-	jr z, .regularCenter
-	ld hl, LooksContentText ; if pikachu is sleeping, don't heal
-	call PrintText
-	ret
-.regularCenter
-	call SaveScreenTilesToBuffer1 ; save screen
-	ld hl, PokemonCenterWelcomeText
-	call PrintText
-	ld hl, wd72e
-	bit 2, [hl]
-	set 1, [hl]
-	set 2, [hl]
-	jr nz, .skipShallWeHealYourPokemon
-	ld hl, ShallWeHealYourPokemonText
-	call PrintText
-.skipShallWeHealYourPokemon
-	call YesNoChoicePokeCenter ; yes/no menu
-	call UpdateSprites
-	ld a, [wCurrentMenuItem]
-	and a
-	jp nz, .declinedHealing ; if the player chose No
-	call SetLastBlackoutMap
-	callab IsStarterPikachuInOurParty
-	jr nc, .notHealingPlayerPikachu
-	call CheckPikachuFollowingPlayer
-	jr nz, .notHealingPlayerPikachu
-	call LoadCurrentMapView
-	call Delay3
-	call UpdateSprites
-	callab PikachuWalksToNurseJoy ; todo
-.notHealingPlayerPikachu
-	ld hl, NeedYourPokemonText
-	call PrintText
-	ld c, 64
-	call DelayFrames
-	call CheckPikachuFollowingPlayer
-	jr nz, .playerPikachuNotOnScreen
-	call DisablePikachuOverworldSpriteDrawing
-	callab IsStarterPikachuInOurParty
-	call c, Func_6eaa
-.playerPikachuNotOnScreen
-	lb bc, 1, 8
-	call Func_6ebb
-	ld c, 30
-	call DelayFrames
-	callba AnimateHealingMachine ; do the healing machine animation
-	predef HealParty
-	xor a
-	ld [wAudioFadeOutControl], a
-	ld a, [wAudioSavedROMBank]
-	ld [wAudioROMBank], a
-	ld a, [wMapMusicSoundID]
-	ld [wLastMusicSoundID], a
-	ld [wNewSoundID], a
-	call PlaySound
-	call CheckPikachuFollowingPlayer
-	jr nz, .doNotReturnPikachu
-	callab IsStarterPikachuInOurParty
-	call c, Func_6eaa
-	ld a, $5
-	ld [wPikachuSpawnState], a
-	call EnablePikachuOverworldSpriteDrawing
-.doNotReturnPikachu
-	lb bc, 1, 0
-	call Func_6ebb
-	ld hl, PokemonFightingFitText
-	call PrintText
-	callab IsStarterPikachuInOurParty
-	jr nc, .notInParty
-	lb bc, 15, 0
-	call Func_6ebb
-.notInParty
-	call LoadCurrentMapView
-	call Delay3
-	call UpdateSprites
-	callab ReloadWalkingTilePatterns
-	ld a, $1
-	ld [H_SPRITEINDEX], a
-	ld a, $1
-	ld [hSpriteImageIndex], a
-	call SpriteFunc_34a1
-	ld c, 40
-	call DelayFrames
-	call UpdateSprites
-	call LoadFontTilePatterns
-	jr .done
-.declinedHealing
-	call LoadScreenTilesFromBuffer1 ; restore screen
-.done
-	ld hl, PokemonCenterFarewellText
-	call PrintText
-	call UpdateSprites
-	ret
-
-Func_6eaa:
-	ld a, $1
-	ld [H_SPRITEINDEX], a
-	ld a, $4
-	ld [hSpriteImageIndex], a
-	call SpriteFunc_34a1
-	ld c, 64
-	call DelayFrames
-	ret
-
-Func_6ebb:
-	ld a, b
-	ld [H_SPRITEINDEX], a
-	ld a, c
-	ld [hSpriteImageIndex], a
-	push bc
-	call SetSpriteFacingDirectionAndDelay
-	pop bc
-	ld a, b
-	ld [H_SPRITEINDEX], a
-	ld a, c
-	ld [hSpriteImageIndex], a
-	call SpriteFunc_34a1
-	ret
-
-PokemonCenterWelcomeText:
-	TX_FAR _PokemonCenterWelcomeText
-	db "@"
-
-ShallWeHealYourPokemonText:
-	TX_DELAY
-	TX_FAR _ShallWeHealYourPokemonText
-	db "@"
-
-NeedYourPokemonText:
-	TX_FAR _NeedYourPokemonText
-	db "@"
-
-PokemonFightingFitText:
-	TX_FAR _PokemonFightingFitText
-	db "@"
-
-PokemonCenterFarewellText:
-	TX_DELAY
-	TX_FAR _PokemonCenterFarewellText
-	db "@"
-
-LooksContentText:
-	TX_FAR _LooksContentText
-	db "@"
diff --git a/engine/overworld/pokemart.asm b/engine/overworld/pokemart.asm
deleted file mode 100755
index dc5b29b5..00000000
--- a/engine/overworld/pokemart.asm
+++ /dev/null
@@ -1,272 +0,0 @@
-DisplayPokemartDialogue_:
-	ld a, [wListScrollOffset]
-	ld [wSavedListScrollOffset], a
-	call UpdateSprites
-	xor a
-	ld [wBoughtOrSoldItemInMart], a
-.loop
-	xor a
-	ld [wListScrollOffset], a
-	ld [wCurrentMenuItem], a
-	ld [wPlayerMonNumber], a
-	inc a
-	ld [wPrintItemPrices], a
-	ld a, MONEY_BOX
-	ld [wTextBoxID], a
-	call DisplayTextBoxID
-	ld a, BUY_SELL_QUIT_MENU
-	ld [wTextBoxID], a
-	call DisplayTextBoxID
-
-; This code is useless. It copies the address of the pokemart's inventory to hl,
-; but the address is never used.
-	ld hl, wItemListPointer
-	ld a, [hli]
-	ld l, [hl]
-	ld h, a
-
-	ld a, [wMenuExitMethod]
-	cp CANCELLED_MENU
-	jp z, .done
-	ld a, [wChosenMenuItem]
-	and a ; buying?
-	jp z, .buyMenu
-	dec a ; selling?
-	jp z, .sellMenu
-	dec a ; quitting?
-	jp z, .done
-.sellMenu
-
-; the same variables are set again below, so this code has no effect
-	xor a
-	ld [wPrintItemPrices], a
-	ld a, INIT_BAG_ITEM_LIST
-	ld [wInitListType], a
-	callab InitList
-
-	ld a, [wNumBagItems]
-	and a
-	jp z, .bagEmpty
-	ld hl, PokemonSellingGreetingText
-	call PrintText
-	call SaveScreenTilesToBuffer1 ; save screen
-.sellMenuLoop
-	call LoadScreenTilesFromBuffer1 ; restore saved screen
-	ld a, MONEY_BOX
-	ld [wTextBoxID], a
-	call DisplayTextBoxID ; draw money text box
-	ld hl, wNumBagItems
-	ld a, l
-	ld [wListPointer], a
-	ld a, h
-	ld [wListPointer + 1], a
-	xor a
-	ld [wPrintItemPrices], a
-	ld [wCurrentMenuItem], a
-	ld a, ITEMLISTMENU
-	ld [wListMenuID], a
-	call DisplayListMenuID
-	jp c, .returnToMainPokemartMenu ; if the player closed the menu
-.confirmItemSale ; if the player is trying to sell a specific item
-	call IsKeyItem
-	ld a, [wIsKeyItem]
-	and a
-	jr nz, .unsellableItem
-	ld a, [wcf91]
-	call IsItemHM
-	jr c, .unsellableItem
-	ld a, PRICEDITEMLISTMENU
-	ld [wListMenuID], a
-	ld [hHalveItemPrices], a ; halve prices when selling
-	call DisplayChooseQuantityMenu
-	inc a
-	jr z, .sellMenuLoop ; if the player closed the choose quantity menu with the B button
-	ld hl, PokemartTellSellPriceText
-	lb bc, 14, 1 ; location that PrintText always prints to, this is useless
-	call PrintText
-	coord hl, 14, 7
-	lb bc, 8, 15
-	ld a, TWO_OPTION_MENU
-	ld [wTextBoxID], a
-	call DisplayTextBoxID ; yes/no menu
-	ld a, [wMenuExitMethod]
-	cp CHOSE_SECOND_ITEM
-	jr z, .sellMenuLoop ; if the player chose No or pressed the B button
-
-; The following code is supposed to check if the player chose No, but the above
-; check already catches it.
-	ld a, [wChosenMenuItem]
-	dec a
-	jr z, .sellMenuLoop
-
-.sellItem
-	ld a, [wBoughtOrSoldItemInMart]
-	and a
-	jr nz, .skipSettingFlag1
-	inc a
-	ld [wBoughtOrSoldItemInMart], a
-.skipSettingFlag1
-	call AddAmountSoldToMoney
-	ld hl, wNumBagItems
-	call RemoveItemFromInventory
-	jp .sellMenuLoop
-.unsellableItem
-	ld hl, PokemartUnsellableItemText
-	call PrintText
-	jp .returnToMainPokemartMenu
-.bagEmpty
-	ld hl, PokemartItemBagEmptyText
-	call PrintText
-	call SaveScreenTilesToBuffer1
-	jp .returnToMainPokemartMenu
-.buyMenu
-
-; the same variables are set again below, so this code has no effect
-	ld a, 1
-	ld [wPrintItemPrices], a
-	ld a, INIT_OTHER_ITEM_LIST
-	ld [wInitListType], a
-	callab InitList
-
-	ld hl, PokemartBuyingGreetingText
-	call PrintText
-	call SaveScreenTilesToBuffer1
-.buyMenuLoop
-	call LoadScreenTilesFromBuffer1
-	ld a, MONEY_BOX
-	ld [wTextBoxID], a
-	call DisplayTextBoxID
-	ld hl, wItemList
-	ld a, l
-	ld [wListPointer], a
-	ld a, h
-	ld [wListPointer + 1], a
-	xor a
-	ld [wCurrentMenuItem], a
-	inc a
-	ld [wPrintItemPrices], a
-	inc a ; a = 2 (PRICEDITEMLISTMENU)
-	ld [wListMenuID], a
-	call DisplayListMenuID
-	jr c, .returnToMainPokemartMenu ; if the player closed the menu
-	ld a, 99
-	ld [wMaxItemQuantity], a
-	xor a
-	ld [hHalveItemPrices], a ; don't halve item prices when buying
-	call DisplayChooseQuantityMenu
-	inc a
-	jr z, .buyMenuLoop ; if the player closed the choose quantity menu with the B button
-	ld a, [wcf91] ; item ID
-	ld [wd11e], a ; store item ID for GetItemName
-	call GetItemName
-	call CopyStringToCF4B ; copy name to wcf4b
-	ld hl, PokemartTellBuyPriceText
-	call PrintText
-	coord hl, 14, 7
-	lb bc, 8, 15
-	ld a, TWO_OPTION_MENU
-	ld [wTextBoxID], a
-	call DisplayTextBoxID ; yes/no menu
-	ld a, [wMenuExitMethod]
-	cp CHOSE_SECOND_ITEM
-	jp z, .buyMenuLoop ; if the player chose No or pressed the B button
-
-; The following code is supposed to check if the player chose No, but the above
-; check already catches it.
-	ld a, [wChosenMenuItem]
-	dec a
-	jr z, .buyMenuLoop
-
-.buyItem
-	call .isThereEnoughMoney
-	jr c, .notEnoughMoney
-	ld hl, wNumBagItems
-	call AddItemToInventory
-	jr nc, .bagFull
-	call SubtractAmountPaidFromMoney
-	ld a, [wBoughtOrSoldItemInMart]
-	and a
-	jr nz, .skipSettingFlag2
-	ld a, 1
-	ld [wBoughtOrSoldItemInMart], a
-.skipSettingFlag2
-	ld a, SFX_PURCHASE
-	call PlaySoundWaitForCurrent
-	call WaitForSoundToFinish
-	ld hl, PokemartBoughtItemText
-	call PrintText
-	jp .buyMenuLoop
-.returnToMainPokemartMenu
-	call LoadScreenTilesFromBuffer1
-	ld a, MONEY_BOX
-	ld [wTextBoxID], a
-	call DisplayTextBoxID
-	ld hl, PokemartAnythingElseText
-	call PrintText
-	jp .loop
-.isThereEnoughMoney
-	ld de, wPlayerMoney
-	ld hl, hMoney
-	ld c, 3 ; length of money in bytes
-	jp StringCmp
-.notEnoughMoney
-	ld hl, PokemartNotEnoughMoneyText
-	call PrintText
-	jr .returnToMainPokemartMenu
-.bagFull
-	ld hl, PokemartItemBagFullText
-	call PrintText
-	jr .returnToMainPokemartMenu
-.done
-	ld hl, PokemartThankYouText
-	call PrintText
-	ld a, 1
-	ld [wUpdateSpritesEnabled], a
-	call UpdateSprites
-	ld a, [wSavedListScrollOffset]
-	ld [wListScrollOffset], a
-	ret
-
-PokemartBuyingGreetingText:
-	TX_FAR _PokemartBuyingGreetingText
-	db "@"
-
-PokemartTellBuyPriceText:
-	TX_FAR _PokemartTellBuyPriceText
-	db "@"
-
-PokemartBoughtItemText:
-	TX_FAR _PokemartBoughtItemText
-	db "@"
-
-PokemartNotEnoughMoneyText:
-	TX_FAR _PokemartNotEnoughMoneyText
-	db "@"
-
-PokemartItemBagFullText:
-	TX_FAR _PokemartItemBagFullText
-	db "@"
-
-PokemonSellingGreetingText:
-	TX_FAR _PokemonSellingGreetingText
-	db "@"
-
-PokemartTellSellPriceText:
-	TX_FAR _PokemartTellSellPriceText
-	db "@"
-
-PokemartItemBagEmptyText:
-	TX_FAR _PokemartItemBagEmptyText
-	db "@"
-
-PokemartUnsellableItemText:
-	TX_FAR _PokemartUnsellableItemText
-	db "@"
-
-PokemartThankYouText:
-	TX_FAR _PokemartThankYouText
-	db "@"
-
-PokemartAnythingElseText:
-	TX_FAR _PokemartAnythingElseText
-	db "@"
diff --git a/engine/overworld/push_boulder.asm b/engine/overworld/push_boulder.asm
index 8a385345..09911ca3 100644
--- a/engine/overworld/push_boulder.asm
+++ b/engine/overworld/push_boulder.asm
@@ -1,4 +1,4 @@
-TryPushingBoulder:
+TryPushingBoulder::
 	ld a, [wd728]
 	bit 0, a ; using Strength?
 	ret z
@@ -8,15 +8,15 @@ Func_f0a7:
 	bit 1, a ; has boulder dust animation from previous push played yet?
 	ret nz
 	xor a
-	ld [hSpriteIndexOrTextID], a
+	ldh [hSpriteIndexOrTextID], a
 	call IsSpriteInFrontOfPlayer
-	ld a, [hSpriteIndexOrTextID]
+	ldh a, [hSpriteIndexOrTextID]
 	ld [wBoulderSpriteIndex], a
 	and a
 	jp z, ResetBoulderPushFlags
-	ld hl, wSpriteStateData1 + 1
+	ld hl, wSpritePlayerStateData1MovementStatus
 	ld d, $0
-	ld a, [hSpriteIndexOrTextID]
+	ldh a, [hSpriteIndexOrTextID]
 	swap a
 	ld e, a
 	add hl, de
@@ -29,16 +29,16 @@ Func_f0a7:
 	bit 6, [hl]
 	set 6, [hl] ; indicate that the player has tried pushing
 	ret z ; the player must try pushing twice before the boulder will move
-	ld a, [hJoyHeld]
+	ldh a, [hJoyHeld]
 	and D_RIGHT | D_LEFT | D_UP | D_DOWN
 	ret z
 	predef CheckForCollisionWhenPushingBoulder
 	ld a, [wTileInFrontOfBoulderAndBoulderCollisionResult]
 	and a ; was there a collision?
 	jp nz, ResetBoulderPushFlags
-	ld a, [hJoyHeld]
+	ldh a, [hJoyHeld]
 	ld b, a
-	ld a, [wSpritePlayerStateData1FacingDirection] ; player's sprite facing direction
+	ld a, [wSpritePlayerStateData1FacingDirection]
 	cp SPRITE_FACING_UP
 	jr z, .pushBoulderUp
 	cp SPRITE_FACING_LEFT
@@ -73,28 +73,32 @@ Func_f0a7:
 	ret
 
 PushBoulderUpMovementData:
-	db NPC_MOVEMENT_UP,$FF
+	db NPC_MOVEMENT_UP
+	db -1 ; end
 
 PushBoulderDownMovementData:
-	db NPC_MOVEMENT_DOWN,$FF
+	db NPC_MOVEMENT_DOWN
+	db -1 ; end
 
 PushBoulderLeftMovementData:
-	db NPC_MOVEMENT_LEFT,$FF
+	db NPC_MOVEMENT_LEFT
+	db -1 ; end
 
 PushBoulderRightMovementData:
-	db NPC_MOVEMENT_RIGHT,$FF
+	db NPC_MOVEMENT_RIGHT
+	db -1 ; end
 
-DoBoulderDustAnimation:
+DoBoulderDustAnimation::
 	ld a, [wd730]
 	bit 0, a
 	ret nz
-	callab AnimateBoulderDust
+	callfar AnimateBoulderDust
 	call DiscardButtonPresses
 	ld [wJoyIgnore], a
 	call ResetBoulderPushFlags
 	set 7, [hl]
 	ld a, [wBoulderSpriteIndex]
-	ld [H_SPRITEINDEX], a
+	ldh [hSpriteIndex], a
 	call GetSpriteMovementByte2Pointer
 	ld [hl], $10
 	ld a, SFX_CUT
diff --git a/engine/overworld/saffron_guards.asm b/engine/overworld/saffron_guards.asm
deleted file mode 100755
index 3b26b6f8..00000000
--- a/engine/overworld/saffron_guards.asm
+++ /dev/null
@@ -1,16 +0,0 @@
-RemoveGuardDrink:
-	ld hl, GuardDrinksList
-.drinkLoop
-	ld a, [hli]
-	ld [$ffdb], a
-	and a
-	ret z
-	push hl
-	ld b, a
-	call IsItemInBag
-	pop hl
-	jr z, .drinkLoop
-	jpba RemoveItemByID
-
-GuardDrinksList:
-	db FRESH_WATER, SODA_POP, LEMONADE, $00
diff --git a/engine/overworld/set_blackout_map.asm b/engine/overworld/set_blackout_map.asm
deleted file mode 100644
index bac2f0ca..00000000
--- a/engine/overworld/set_blackout_map.asm
+++ /dev/null
@@ -1,29 +0,0 @@
-SetLastBlackoutMap:
-; Set the map to return to when
-; blacking out or using Teleport or Dig.
-; Safari rest houses don't count.
-
-	push hl
-	ld hl, SafariZoneRestHouses
-	ld a, [wCurMap]
-	ld b, a
-.loop
-	ld a, [hli]
-	cp -1
-	jr z, .notresthouse
-	cp b
-	jr nz, .loop
-	jr .done
-
-.notresthouse
-	ld a, [wLastMap]
-	ld [wLastBlackoutMap], a
-.done
-	pop hl
-	ret
-
-SafariZoneRestHouses:
-	db SAFARI_ZONE_WEST_REST_HOUSE
-	db SAFARI_ZONE_EAST_REST_HOUSE
-	db SAFARI_ZONE_NORTH_REST_HOUSE
-	db -1
diff --git a/engine/overworld/special_warps.asm b/engine/overworld/special_warps.asm
new file mode 100644
index 00000000..61356a03
--- /dev/null
+++ b/engine/overworld/special_warps.asm
@@ -0,0 +1,149 @@
+SpecialWarpIn::
+	call LoadSpecialWarpData
+	predef LoadTilesetHeader
+	ld hl, wd732
+	bit 2, [hl] ; dungeon warp or fly warp?
+	res 2, [hl]
+	jr z, .next
+; if dungeon warp or fly warp
+	ld a, [wDestinationMap]
+	jr .next2
+.next
+	bit 1, [hl]
+	jr z, .next3
+	call DebugStart
+.next3
+	ld a, 0
+.next2
+	ld b, a
+	ld a, [wd72d]
+	and a
+	jr nz, .next4
+	ld a, b
+.next4
+	ld hl, wd732
+	bit 4, [hl] ; dungeon warp?
+	ret nz
+; if not dungeon warp
+	ld [wLastMap], a
+	ret
+
+; gets the map ID, tile block map view pointer, tileset, and coordinates
+LoadSpecialWarpData:
+	ld a, [wd72d]
+	cp TRADE_CENTER
+	jr nz, .notTradeCenter
+	ld hl, TradeCenterSpec1
+	ldh a, [hSerialConnectionStatus]
+	cp USING_INTERNAL_CLOCK ; which gameboy is clocking determines who is on the left and who is on the right
+	jr z, .copyWarpData
+	ld hl, TradeCenterSpec2
+	jr .copyWarpData
+.notTradeCenter
+	cp COLOSSEUM
+	jr nz, .notColosseum
+	ld hl, ColosseumSpec1
+	ldh a, [hSerialConnectionStatus]
+	cp USING_INTERNAL_CLOCK
+	jr z, .copyWarpData
+	ld hl, ColosseumSpec2
+	jr .copyWarpData
+.notColosseum
+	ld a, [wd732]
+	bit 1, a
+	jr nz, .notFirstMap
+	bit 2, a
+	jr nz, .notFirstMap
+	ld hl, FirstMapSpec
+.copyWarpData
+	ld de, wCurMap
+	ld c, $7
+.copyWarpDataLoop
+	ld a, [hli]
+	ld [de], a
+	inc de
+	dec c
+	jr nz, .copyWarpDataLoop
+	ld a, [hli]
+	ld [wCurMapTileset], a
+	xor a
+	jr .done
+.notFirstMap
+	ld a, [wLastMap] ; this value is overwritten before it's ever read
+	ld hl, wd732
+	bit 4, [hl] ; used dungeon warp (jumped down hole/waterfall)?
+	jr nz, .usedDunegonWarp
+	bit 6, [hl] ; return to last pokemon center (or player's house)?
+	res 6, [hl]
+	jr z, .otherDestination
+; return to last pokemon center or player's house
+	ld a, [wLastBlackoutMap]
+	jr .usedFlyWarp
+.usedDunegonWarp
+	ld hl, wd72d
+	res 4, [hl]
+	ld a, [wDungeonWarpDestinationMap]
+	ld b, a
+	ld [wCurMap], a
+	ld a, [wWhichDungeonWarp]
+	ld c, a
+	ld hl, DungeonWarpList
+	ld de, 0
+	ld a, 6
+	ld [wDungeonWarpDataEntrySize], a
+.dungeonWarpListLoop
+	ld a, [hli]
+	cp b
+	jr z, .matchedDungeonWarpDestinationMap
+	inc hl
+	jr .nextDungeonWarp
+.matchedDungeonWarpDestinationMap
+	ld a, [hli]
+	cp c
+	jr z, .matchedDungeonWarpID
+.nextDungeonWarp
+	ld a, [wDungeonWarpDataEntrySize]
+	add e
+	ld e, a
+	jr .dungeonWarpListLoop
+.matchedDungeonWarpID
+	ld hl, DungeonWarpData
+	add hl, de
+	jr .copyWarpData2
+.otherDestination
+	ld a, [wDestinationMap]
+.usedFlyWarp
+	ld b, a
+	ld [wCurMap], a
+	ld hl, FlyWarpDataPtr
+.flyWarpDataPtrLoop
+	ld a, [hli]
+	inc hl
+	cp b
+	jr z, .foundFlyWarpMatch
+	inc hl
+	inc hl
+	jr .flyWarpDataPtrLoop
+.foundFlyWarpMatch
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+.copyWarpData2
+	ld de, wCurrentTileBlockMapViewPointer
+	ld c, $6
+.copyWarpDataLoop2
+	ld a, [hli]
+	ld [de], a
+	inc de
+	dec c
+	jr nz, .copyWarpDataLoop2
+	xor a ; OVERWORLD
+	ld [wCurMapTileset], a
+.done
+	ld [wYOffsetSinceLastSpecialWarp], a
+	ld [wXOffsetSinceLastSpecialWarp], a
+	ld a, $ff ; the player's coordinates have already been updated using a special warp, so don't use any of the normal warps
+	ld [wDestinationWarpID], a
+	ret
+
+INCLUDE "data/maps/special_warps.asm"
diff --git a/engine/overworld/spinners.asm b/engine/overworld/spinners.asm
new file mode 100644
index 00000000..0ac6380d
--- /dev/null
+++ b/engine/overworld/spinners.asm
@@ -0,0 +1,65 @@
+LoadSpinnerArrowTiles::
+	ld a, [wSpritePlayerStateData1ImageIndex]
+	srl a
+	srl a
+	ld hl, SpinnerPlayerFacingDirections
+	ld c, a
+	ld b, $0
+	add hl, bc
+	ld a, [hl]
+	ld [wSpritePlayerStateData1ImageIndex], a
+	ld a, [wCurMapTileset]
+	cp FACILITY
+	ld hl, FacilitySpinnerArrows
+	jr z, .asm_44ff6
+	ld hl, GymSpinnerArrows
+.asm_44ff6
+	ld a, [wSimulatedJoypadStatesIndex]
+	bit 0, a
+	jr nz, .asm_45001
+	ld de, $18
+	add hl, de
+.asm_45001
+	ld a, $4
+	ld bc, $0
+.asm_45006
+	push af
+	push hl
+	push bc
+	add hl, bc
+	ld a, [hli]
+	ld e, a
+	ld a, [hli]
+	ld d, a
+	ld a, [hli]
+	ld c, a
+	ld a, [hli]
+	ld b, a
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	call CopyVideoData
+	pop bc
+	ld a, $6
+	add c
+	ld c, a
+	pop hl
+	pop af
+	dec a
+	jr nz, .asm_45006
+	ret
+
+INCLUDE "data/tilesets/spinner_tiles.asm"
+
+SpinnerPlayerFacingDirections:
+; This isn't the order of the facing directions.  Rather, it's a list of
+; the facing directions that come next. For example, when the player is
+; facing down (00), the next facing direction is left (08).
+	db $08 ; down -> left
+	db $0C ; up -> right
+	db $04 ; left -> up
+	db $00 ; right -> down
+
+; these tiles are the animation for the tiles that push the player in dungeons like Rocket HQ
+SpinnerArrowAnimTiles:
+	INCBIN "gfx/overworld/spinners.2bpp"
diff --git a/engine/overworld/map_sprite_functions1.asm b/engine/overworld/sprite_collisions.asm
index 2ad923fb..db81977b 100644
--- a/engine/overworld/map_sprite_functions1.asm
+++ b/engine/overworld/sprite_collisions.asm
@@ -1,15 +1,15 @@
-_UpdateSprites:
+_UpdateSprites::
 	ld h, wSpriteStateData1 / $100
 	inc h
-	ld a, $e    ; (wSpriteStateData2 + $0e) & $ff
+	ld a, SPRITESTATEDATA2_IMAGEBASEOFFSET
 .spriteLoop
 	ld l, a
-	sub $e
+	sub SPRITESTATEDATA2_IMAGEBASEOFFSET
 	ld c, a
-	ld [H_CURRENTSPRITEOFFSET], a
+	ldh [hCurrentSpriteOffset], a
 	ld a, [hl]
 	and a
-	jr z, .skipSprite   ; tests $c2Xe
+	jr z, .skipSprite   ; tests SPRITESTATEDATA2_IMAGEBASEOFFSET
 	push hl
 	push de
 	push bc
@@ -20,11 +20,11 @@ _UpdateSprites:
 .skipSprite
 	ld a, l
 	add $10             ; move to next sprite
-	cp $e               ; test for overflow (back at $0e)
+	cp SPRITESTATEDATA2_IMAGEBASEOFFSET ; test for overflow (back at beginning)
 	jr nz, .spriteLoop
 	ret
 .updateCurrentSprite
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	and a
 	jp z, UpdatePlayerSprite
 	cp $f0 ; pikachu
@@ -34,33 +34,34 @@ _UpdateSprites:
 UpdateNonPlayerSprite:
 	dec a
 	swap a
-	ld [$ff93], a  ; $10 * sprite#
+	ldh [hTilePlayerStandingOn], a  ; $10 * sprite#
 	ld a, [wNPCMovementScriptSpriteOffset] ; some sprite offset?
 	ld b, a
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	cp b
 	jr nz, .unequal
 	jp DoScriptedNPCMovement
 .unequal
 	jp UpdateNPCSprite
 
-; This detects if the current sprite (whose offset is at H_CURRENTSPRITEOFFSET)
+; This detects if the current sprite (whose offset is at hCurrentSpriteOffset)
 ; is going to collide with another sprite by looping over the other sprites.
-; The current sprite's offset will be labelled with i (e.g. $c1i0).
-; The loop sprite's offset will labelled with j (e.g. $c1j0).
+; The current sprite's offset will be labelled with i (e.g. i#SPRITESTATEDATA1_PICTUREID).
+; The loop sprite's offset will labelled with j (e.g. j#SPRITESTATEDATA1_PICTUREID).
 ;
-; Note that the Y coordinate of the sprite (in [$c1k4]) is one of the following
-; 9 values when the sprite is aligned with the grid: $fc, $0c, $1c, $2c, ..., $7c.
+; Note that the Y coordinate of the sprite (in [k#SPRITESTATEDATA1_YPIXELS])
+; is one of the following 9 values when the sprite is aligned with the grid:
+; $fc, $0c, $1c, $2c, ..., $7c.
 ; The reason that 4 is added below to the coordinate is to make it align with a
 ; multiple of $10 to make comparisons easier.
 DetectCollisionBetweenSprites:
 	; nop
 
-	ld h, wSpriteStateData1 / $100
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ld h, HIGH(wSpriteStateData1)
+	ldh a, [hCurrentSpriteOffset]
 	ld l, a
 
-	ld a, [hl] ; a = [$c1i0] (picture) (0 if slot is unused)
+	ld a, [hl] ; a = [i#SPRITESTATEDATA1_PICTUREID] (0 if slot is unused)
 	and a ; is this sprite slot slot used?
 	ret z ; return if not used
 
@@ -68,10 +69,10 @@ DetectCollisionBetweenSprites:
 	add 3
 	ld l, a
 
-	ld a, [hli] ; a = [$c1i3] (delta Y) (-1, 0, or 1)
+	ld a, [hli] ; a = [i#SPRITESTATEDATA1_YSTEPVECTOR] (-1, 0, or 1)
 	call SetSpriteCollisionValues
 
-	ld a, [hli] ; a = [$C1i4] (Y screen coordinate)
+	ld a, [hli] ; a = [i#SPRITESTATEDATA1_YPIXELS]
 	add 4 ; align with multiple of $10
 
 ; The effect of the following 3 lines is to
@@ -81,11 +82,11 @@ DetectCollisionBetweenSprites:
 	and $f0
 	or c
 
-	ld [$ff90], a ; store Y coordinate adjusted for direction of movement
+	ldh [hFF90], a ; store Y coordinate adjusted for direction of movement
 
-	ld a, [hli] ; a = [$c1i5] (delta X) (-1, 0, or 1)
+	ld a, [hli] ; a = [i#SPRITESTATEDATA1_XSTEPVECTOR] (-1, 0, or 1)
 	call SetSpriteCollisionValues
-	ld a, [hl] ; a = [$C1i6] (X screen coordinate)
+	ld a, [hl] ; a = [i#SPRITESTATEDATA1_XPIXELS]
 
 ; The effect of the following 3 lines is to
 ; add 7 to a if moving east or
@@ -94,52 +95,52 @@ DetectCollisionBetweenSprites:
 	and $f0
 	or c
 
-	ld [$ff91], a ; store X coordinate adjusted for direction of movement
+	ldh [hFF91], a ; store X coordinate adjusted for direction of movement
 
 	ld a, l
 	add 7
 	ld l, a
 
 	xor a
-	ld [hld], a ; zero [$c1id] XXX what's [$c1id] for?
-	ld [hld], a ; zero [$c1ic] (directions in which collisions occurred)
+	ld [hld], a ; zero [i#SPRITESTATEDATA1_0D] XXX what's this for?
+	ld [hld], a ; zero [i#SPRITESTATEDATA1_COLLISIONDATA]
 
-	ld a, [$ff91]
-	ld [hld], a ; [$c1ib] = adjusted X coordinate
-	ld a, [$ff90]
-	ld [hl], a ; [$c1ia] = adjusted Y coordinate
+	ldh a, [hFF91]
+	ld [hld], a ; [i#SPRITESTATEDATA1_XADJUSTED]
+	ldh a, [hFF90]
+	ld [hl], a ; [i#SPRITESTATEDATA1_YADJUSTED]
 
 	xor a ; zero the loop counter
 
 .loop
-	ld [$ff8f], a ; store loop counter
+	ldh [hFF8F], a ; store loop counter
 	swap a
 	ld e, a
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	cp e ; does the loop sprite match the current sprite?
 	jp z, .next ; go to the next sprite if they match
 
 	ld d, h
-	ld a, [de] ; a = [$c1j0] (picture) (0 if slot is unused)
+	ld a, [de] ; a = [j#SPRITESTATEDATA1_PICTUREID] (0 if slot is unused)
 	and a ; is this sprite slot slot used?
 	jp z, .next ; go the next sprite if not used
 
 	inc e
 	inc e
-	ld a, [de] ; a = [$c1j2] ($ff means the sprite is offscreen)
+	ld a, [de] ; a = [j#SPRITESTATEDATA1_IMAGEINDEX] ($ff means the sprite is offscreen)
 	inc a
 	jp z, .next ; go the next sprite if offscreen
 
-	ld a, [H_CURRENTSPRITEOFFSET]
+	ldh a, [hCurrentSpriteOffset]
 	add 10
 	ld l, a
 
 	inc e
-	ld a, [de] ; a = [$c1j3] (delta Y)
+	ld a, [de] ; a = [j#SPRITESTATEDATA1_YSTEPVECTOR]
 	call SetSpriteCollisionValues
 
 	inc e
-	ld a, [de] ; a = [$C1j4] (Y screen coordinate)
+	ld a, [de] ; a = [j#SPRITESTATEDATA1_YPIXELS]
 	add 4 ; align with multiple of $10
 
 ; The effect of the following 3 lines is to
@@ -149,18 +150,18 @@ DetectCollisionBetweenSprites:
 	and $f0
 	or c
 
-	sub [hl] ; subtract the adjusted Y coordinate of sprite i ([$c1ia]) from that of sprite j
+	sub [hl] ; subtract [i#SPRITESTATEDATA1_YADJUSTED] from [j#SPRITESTATEDATA1_YADJUSTED]
 
 ; calculate the absolute value of the difference to get the distance
 	jr nc, .noCarry1
 	cpl
 	inc a
 .noCarry1
-	ld [$ff90], a ; store the distance between the two sprites' adjusted Y values
+	ldh [hFF90], a ; store the distance between the two sprites' adjusted Y values
 
 ; Use the carry flag set by the above subtraction to determine which sprite's
-; Y coordinate is larger. This information is used later to set [$c1ic],
-; which stores which direction the collision occurred in.
+; Y coordinate is larger. This information is used later to set
+; [i#SPRITESTATEDATA1_COLLISIONDATA].
 ; The following 5 lines set the lowest 2 bits of c, which are later shifted left by 2.
 ; If sprite i's Y is larger, set lowest 2 bits of c to 10.
 ; If sprite j's Y is larger or both are equal, set lowest 2 bits of c to 01.
@@ -172,30 +173,30 @@ DetectCollisionBetweenSprites:
 
 ; If sprite i's delta Y is 0, then b = 7, else b = 9.
 	ld b, 7
-	ld a, [hl] ; a = [$c1ia] (adjusted Y coordinate)
+	ld a, [hl] ; a = [i#SPRITESTATEDATA1_YADJUSTED]
 	and $f
 	jr z, .next1
 	ld b, 9
 
 .next1
-	ld a, [$ff90] ; a = distance between adjusted Y coordinates
+	ldh a, [hFF90] ; a = distance between adjusted Y coordinates
 	sub b
-	ld [$ff92], a ; store distance adjusted using sprite i's direction
+	ldh [hFF92], a ; store distance adjusted using sprite i's direction
 	ld a, b
-	ld [$ff90], a ; store 7 or 9 depending on sprite i's delta Y
+	ldh [hFF90], a ; store 7 or 9 depending on sprite i's delta Y
 	jr c, .checkXDistance
 
 ; If sprite j's delta Y is 0, then b = 7, else b = 9.
 	ld b, 7
 	dec e
-	ld a, [de] ; a = [$c1j3] (delta Y)
+	ld a, [de] ; a = [j#SPRITESTATEDATA1_YSTEPVECTOR]
 	inc e
 	and a
 	jr z, .next2
 	ld b, 9
 
 .next2
-	ld a, [$ff92] ; a = distance adjusted using sprite i's direction
+	ldh a, [hFF92] ; a = distance adjusted using sprite i's direction
 	sub b ; adjust distance using sprite j's direction
 	jr z, .checkXDistance
 	jr nc, .next ; go to next sprite if distance is still positive after both adjustments
@@ -203,13 +204,13 @@ DetectCollisionBetweenSprites:
 .checkXDistance
 	inc e
 	inc l
-	ld a, [de] ; a = [$c1j5] (delta X)
+	ld a, [de] ; a = [j#SPRITESTATEDATA1_XSTEPVECTOR]
 
 	push bc
 
 	call SetSpriteCollisionValues
 	inc e
-	ld a, [de] ; a = [$c1j6] (X screen coordinate)
+	ld a, [de] ; a = [j#SPRITESTATEDATA1_XPIXELS]
 
 ; The effect of the following 3 lines is to
 ; add 7 to a if moving east or
@@ -220,18 +221,18 @@ DetectCollisionBetweenSprites:
 
 	pop bc
 
-	sub [hl] ; subtract the adjusted X coordinate of sprite i ([$c1ib]) from that of sprite j
+	sub [hl] ; subtract [i#SPRITESTATEDATA1_XADJUSTED] from [j#SPRITESTATEDATA1_XADJUSTED]
 
 ; calculate the absolute value of the difference to get the distance
 	jr nc, .noCarry2
 	cpl
 	inc a
 .noCarry2
-	ld [$ff91], a ; store the distance between the two sprites' adjusted X values
+	ldh [hFF91], a ; store the distance between the two sprites' adjusted X values
 
 ; Use the carry flag set by the above subtraction to determine which sprite's
-; X coordinate is larger. This information is used later to set [$c1ic],
-; which stores which direction the collision occurred in.
+; X coordinate is larger. This information is used later to set
+; [i#SPRITESTATEDATA1_COLLISIONDATA].
 ; The following 5 lines set the lowest 2 bits of c.
 ; If sprite i's X is larger, set lowest 2 bits of c to 10.
 ; If sprite j's X is larger or both are equal, set lowest 2 bits of c to 01.
@@ -243,30 +244,30 @@ DetectCollisionBetweenSprites:
 
 ; If sprite i's delta X is 0, then b = 7, else b = 9.
 	ld b, 7
-	ld a, [hl] ; a = [$c1ib] (adjusted X coordinate)
+	ld a, [hl] ; a = [i#SPRITESTATEDATA1_XADJUSTED]
 	and $f
 	jr z, .next3
 	ld b, 9
 
 .next3
-	ld a, [$ff91] ; a = distance between adjusted X coordinates
+	ldh a, [hFF91] ; a = distance between adjusted X coordinates
 	sub b
-	ld [$ff92], a ; store distance adjusted using sprite i's direction
+	ldh [hFF92], a ; store distance adjusted using sprite i's direction
 	ld a, b
-	ld [$ff91], a ; store 7 or 9 depending on sprite i's delta X
+	ldh [hFF91], a ; store 7 or 9 depending on sprite i's delta X
 	jr c, .collision
 
 ; If sprite j's delta X is 0, then b = 7, else b = 9.
 	ld b, 7
 	dec e
-	ld a, [de] ; a = [$c1j5] (delta X)
+	ld a, [de] ; a = [j#SPRITESTATEDATA1_XSTEPVECTOR]
 	inc e
 	and a
 	jr z, .next4
 	ld b, 9
 
 .next4
-	ld a, [$ff92] ; a = distance adjusted using sprite i's direction
+	ldh a, [hFF92] ; a = distance adjusted using sprite i's direction
 	sub b ; adjust distance using sprite j's direction
 	jr z, .collision
 	jr nc, .next ; go to next sprite if distance is still positive after both adjustments
@@ -277,15 +278,15 @@ DetectCollisionBetweenSprites:
 	jr nz, .asm_4cd9
 	xor a
 	ld [wd434], a
-	ld a, [$ff8f]
+	ldh a, [hFF8F]
 	cp $f
 	jr nz, .asm_4cd9
 	call Func_4d0a
 	jr .asm_4cef
 .asm_4cd9
-	ld a, [$ff91] ; a = 7 or 9 depending on sprite i's delta X
+	ldh a, [hFF91] ; a = 7 or 9 depending on sprite i's delta X
 	ld b, a
-	ld a, [$ff90] ; a = 7 or 9 depending on sprite i's delta Y
+	ldh a, [hFF90] ; a = 7 or 9 depending on sprite i's delta Y
 	inc l
 
 ; If delta X isn't 0 and delta Y is 0, then b = %0011, else b = %1100.
@@ -300,15 +301,16 @@ DetectCollisionBetweenSprites:
 .next6
 	ld a, c ; c has 2 bits set (one of bits 0-1 is set for the X axis and one of bits 2-3 for the Y axis)
 	and b ; we select either the bit in bits 0-1 or bits 2-3 based on the calculation immediately above
-	or [hl] ; or with existing collision direction bits in [$c1ic]
+	or [hl] ; or with existing collision direction bits in [i#SPRITESTATEDATA1_COLLISIONDATA]
 	ld [hl], a ; store new value
 	ld a, c ; useless code because a is overwritten before being used again
 
-; set bit in [$c1ie] or [$c1if] to indicate which sprite the collision occurred with
+; set bit in [i#SPRITESTATEDATA1_0E] or [i#SPRITESTATEDATA1_0F]
+; to indicate which sprite the collision occurred with
 	inc l
 	inc l
 .asm_4cef
-	ld a, [$ff8f] ; a = loop counter
+	ldh a, [hFF8F] ; a = loop counter
 	ld de, SpriteCollisionBitTable
 	add a
 	add e
@@ -325,7 +327,7 @@ DetectCollisionBetweenSprites:
 	ld [hl], a
 
 .next
-	ld a, [$ff8f] ; a = loop counter
+	ldh a, [hFF8F] ; a = loop counter
 	inc a
 	cp $10
 	jp nz, .loop
@@ -337,9 +339,9 @@ DetectCollisionBetweenSprites:
 ; c = 7 if delta X/Y is 1
 ; c = 9 if delta X/Y is -1
 Func_4d0a:
-	ld a, [$ff91]
+	ldh a, [hFF91]
 	ld b, a
-	ld a, [$ff90]
+	ldh a, [hFF90]
 	inc l
 	cp b
 	jr c, .asm_4d17
diff --git a/engine/overworld/tileset_header.asm b/engine/overworld/tilesets.asm
index 05061651..686fa50c 100644
--- a/engine/overworld/tileset_header.asm
+++ b/engine/overworld/tilesets.asm
@@ -14,9 +14,9 @@ LoadTilesetHeader:
 	ld bc, $b
 	call CopyData
 	ld a, [hl]
-	ld [hTilesetType], a
+	ldh [hTilesetType], a
 	xor a
-	ld [$ffd8], a
+	ldh [hMovingBGTilesCounter1], a
 	pop hl
 	ld a, [wCurMapTileset]
 	push hl
@@ -29,7 +29,7 @@ LoadTilesetHeader:
 	jr c, .notDungeonTileset
 	ld a, [wCurMapTileset]
 	ld b, a
-	ld a, [hPreviousTileset]
+	ldh a, [hPreviousTileset]
 	cp b
 	jr z, .done
 .notDungeonTileset
@@ -46,6 +46,6 @@ LoadTilesetHeader:
 .done
 	ret
 
-INCLUDE "data/dungeon_tilesets.asm"
+INCLUDE "data/tilesets/dungeon_tilesets.asm"
 
-INCLUDE "data/tileset_headers.asm"
+INCLUDE "data/tilesets/tileset_headers.asm"
diff --git a/engine/overworld/trainers.asm b/engine/overworld/trainer_sight.asm
index 655c6b2a..816dea7f 100755
--- a/engine/overworld/trainers.asm
+++ b/engine/overworld/trainer_sight.asm
@@ -1,80 +1,80 @@
-_GetSpritePosition1:
+_GetSpritePosition1::
 	ld hl, wSpriteStateData1
-	ld de, $4
+	ld de, SPRITESTATEDATA1_YPIXELS
 	ld a, [wSpriteIndex]
-	ld [H_SPRITEINDEX], a
+	ldh [hSpriteIndex], a
 	call GetSpriteDataPointer
-	ld a, [hli] ; c1x4 (screen Y pos)
-	ld [$ffeb], a
+	ld a, [hli] ; x#SPRITESTATEDATA1_YPIXELS
+	ldh [hSpriteScreenYCoord], a
 	inc hl
-	ld a, [hl] ; c1x6 (screen X pos)
-	ld [$ffec], a
-	ld de, (wSpriteStateData2 + $4) - (wSpriteStateData1 + $6)
+	ld a, [hl] ; x#SPRITESTATEDATA1_XPIXELS
+	ldh [hSpriteScreenXCoord], a
+	ld de, wSpritePlayerStateData2MapY - wSpritePlayerStateData1XPixels
 	add hl, de
-	ld a, [hli] ; c2x4 (map Y pos)
-	ld [$ffed], a
-	ld a, [hl] ; c2x5 (map X pos)
-	ld [$ffee], a
+	ld a, [hli] ; x#SPRITESTATEDATA2_MAPY
+	ldh [hSpriteMapYCoord], a
+	ld a, [hl] ; x#SPRITESTATEDATA2_MAPX
+	ldh [hSpriteMapXCoord], a
 	ret
 
-_GetSpritePosition2:
+_GetSpritePosition2::
 	ld hl, wSpriteStateData1
-	ld de, $4
+	ld de, SPRITESTATEDATA1_YPIXELS
 	ld a, [wSpriteIndex]
-	ld [H_SPRITEINDEX], a
+	ldh [hSpriteIndex], a
 	call GetSpriteDataPointer
-	ld a, [hli] ; c1x4 (screen Y pos)
+	ld a, [hli] ; x#SPRITESTATEDATA1_YPIXELS
 	ld [wSavedSpriteScreenY], a
 	inc hl
-	ld a, [hl] ; c1x6 (screen X pos)
+	ld a, [hl] ; x#SPRITESTATEDATA1_XPIXELS
 	ld [wSavedSpriteScreenX], a
-	ld de, (wSpriteStateData2 + $4) - (wSpriteStateData1 + $6)
+	ld de, wSpritePlayerStateData2MapY - wSpritePlayerStateData1XPixels
 	add hl, de
-	ld a, [hli] ; c2x4 (map Y pos)
+	ld a, [hli] ; x#SPRITESTATEDATA2_MAPY
 	ld [wSavedSpriteMapY], a
-	ld a, [hl] ; c2x5 (map X pos)
+	ld a, [hl] ; x#SPRITESTATEDATA2_MAPX
 	ld [wSavedSpriteMapX], a
 	ret
 
-_SetSpritePosition1:
+_SetSpritePosition1::
 	ld hl, wSpriteStateData1
-	ld de, $4
+	ld de, SPRITESTATEDATA1_YPIXELS
 	ld a, [wSpriteIndex]
-	ld [H_SPRITEINDEX], a
+	ldh [hSpriteIndex], a
 	call GetSpriteDataPointer
-	ld a, [$ffeb] ; c1x4 (screen Y pos)
+	ldh a, [hSpriteScreenYCoord] ; x#SPRITESTATEDATA1_YPIXELS
 	ld [hli], a
 	inc hl
-	ld a, [$ffec] ; c1x6 (screen X pos)
+	ldh a, [hSpriteScreenXCoord] ; x#SPRITESTATEDATA1_XPIXELS
 	ld [hl], a
-	ld de, (wSpriteStateData2 + $4) - (wSpriteStateData1 + $6)
+	ld de, wSpritePlayerStateData2MapY - wSpritePlayerStateData1XPixels
 	add hl, de
-	ld a, [$ffed] ; c2x4 (map Y pos)
+	ldh a, [hSpriteMapYCoord] ; x#SPRITESTATEDATA2_MAPY
 	ld [hli], a
-	ld a, [$ffee] ; c2x5 (map X pos)
+	ldh a, [hSpriteMapXCoord] ; x#SPRITESTATEDATA2_MAPX
 	ld [hl], a
 	ret
 
-_SetSpritePosition2:
+_SetSpritePosition2::
 	ld hl, wSpriteStateData1
-	ld de, 4
+	ld de, SPRITESTATEDATA1_YPIXELS
 	ld a, [wSpriteIndex]
-	ld [H_SPRITEINDEX], a
+	ldh [hSpriteIndex], a
 	call GetSpriteDataPointer
 	ld a, [wSavedSpriteScreenY]
-	ld [hli], a ; c1x4 (screen Y pos)
+	ld [hli], a ; x#SPRITESTATEDATA1_YPIXELS
 	inc hl
 	ld a, [wSavedSpriteScreenX]
-	ld [hl], a ; c1x6 (screen X pos)
-	ld de, (wSpriteStateData2 + $4) - (wSpriteStateData1 + $6)
+	ld [hl], a ; x#SPRITESTATEDATA1_XPIXELS
+	ld de, wSpritePlayerStateData2MapY - wSpritePlayerStateData1XPixels
 	add hl, de
 	ld a, [wSavedSpriteMapY]
-	ld [hli], a ; c2x4 (map Y pos)
+	ld [hli], a ; x#SPRITESTATEDATA2_MAPY
 	ld a, [wSavedSpriteMapX]
-	ld [hl], a ; c2x5 (map X pos)
+	ld [hl], a ; x#SPRITESTATEDATA2_MAPX
 	ret
 
-TrainerWalkUpToPlayer:
+TrainerWalkUpToPlayer::
 	ld a, [wSpriteIndex]
 	swap a
 	ld [wTrainerSpriteOffset], a
@@ -144,7 +144,7 @@ TrainerWalkUpToPlayer:
 	call FillMemory     ; write the necessary steps to reach player
 	ld [hl], $ff        ; write end of list sentinel
 	ld a, [wSpriteIndex]
-	ld [H_SPRITEINDEX], a
+	ldh [hSpriteIndex], a
 	jp MoveSprite_
 
 ; input: de = offset within sprite entry
@@ -152,7 +152,7 @@ TrainerWalkUpToPlayer:
 GetSpriteDataPointer:
 	push de
 	add hl, de
-	ld a, [H_SPRITEINDEX]
+	ldh a, [hSpriteIndex]
 	swap a
 	ld d, $0
 	ld e, a
@@ -165,23 +165,23 @@ TrainerEngage:
 	push hl
 	push de
 	ld a, [wTrainerSpriteOffset]
-	add $2
+	add SPRITESTATEDATA1_IMAGEINDEX
 	ld d, $0
 	ld e, a
 	ld hl, wSpriteStateData1
 	add hl, de
-	ld a, [hl]             ; c1x2: sprite image index
+	ld a, [hl]             ; x#SPRITESTATEDATA1_IMAGEINDEX
 	sub $ff
 	jr nz, .spriteOnScreen ; test if sprite is on screen
 	jp .noEngage
 .spriteOnScreen
 	ld a, [wTrainerSpriteOffset]
-	add $9
+	add SPRITESTATEDATA1_FACINGDIRECTION
 	ld d, $0
 	ld e, a
 	ld hl, wSpriteStateData1
 	add hl, de
-	ld a, [hl]             ; c1x9: facing direction
+	ld a, [hl]             ; x#SPRITESTATEDATA1_FACINGDIRECTION
 	ld [wTrainerFacingDirection], a
 	call ReadTrainerScreenPosition
 	ld a, [wTrainerScreenY]          ; sprite screen Y pos
@@ -234,20 +234,20 @@ TrainerEngage:
 ; reads trainer's Y position to wTrainerScreenY and X position to wTrainerScreenX
 ReadTrainerScreenPosition:
 	ld a, [wTrainerSpriteOffset]
-	add $4
+	add SPRITESTATEDATA1_YPIXELS
 	ld d, $0
 	ld e, a
 	ld hl, wSpriteStateData1
 	add hl, de
-	ld a, [hl] ; c1x4 (sprite Y pos)
+	ld a, [hl] ; x#SPRITESTATEDATA1_YPIXELS
 	ld [wTrainerScreenY], a
 	ld a, [wTrainerSpriteOffset]
-	add $6
+	add SPRITESTATEDATA1_XPIXELS
 	ld d, $0
 	ld e, a
 	ld hl, wSpriteStateData1
 	add hl, de
-	ld a, [hl] ; c1x6 (sprite X pos)
+	ld a, [hl] ; x#SPRITESTATEDATA1_XPIXELS
 	ld [wTrainerScreenX], a
 	ret
 
@@ -295,24 +295,24 @@ CheckPlayerIsInFrontOfSprite:
 	cp POWER_PLANT
 	jp z, .engage       ; bypass this for power plant to get voltorb fake items to work
 	ld a, [wTrainerSpriteOffset]
-	add $4
+	add SPRITESTATEDATA1_YPIXELS
 	ld d, $0
 	ld e, a
 	ld hl, wSpriteStateData1
 	add hl, de
-	ld a, [hl]          ; c1x4 (sprite screen Y pos)
+	ld a, [hl]          ; x#SPRITESTATEDATA1_YPIXELS
 	cp $fc
 	jr nz, .notOnTopmostTile ; special case if sprite is on topmost tile (Y = $fc (-4)), make it come down a block
 	ld a, $c
 .notOnTopmostTile
 	ld [wTrainerScreenY], a
 	ld a, [wTrainerSpriteOffset]
-	add $6
+	add SPRITESTATEDATA1_XPIXELS
 	ld d, $0
 	ld e, a
 	ld hl, wSpriteStateData1
 	add hl, de
-	ld a, [hl]          ; c1x6 (sprite screen X pos)
+	ld a, [hl]          ; x#SPRITESTATEDATA1_XPIXELS
 	ld [wTrainerScreenX], a
 	ld a, [wTrainerFacingDirection]       ; facing direction
 	cp SPRITE_FACING_DOWN
diff --git a/engine/overworld/update_map.asm b/engine/overworld/update_map.asm
index 8577b9e7..53a5592d 100644
--- a/engine/overworld/update_map.asm
+++ b/engine/overworld/update_map.asm
@@ -50,20 +50,20 @@ RedrawMapView:
 	ld a, [wIsInBattle]
 	inc a
 	ret z
-	ld a, [H_AUTOBGTRANSFERENABLED]
+	ldh a, [hAutoBGTransferEnabled]
 	push af
-	ld a, [hTilesetType]
+	ldh a, [hTilesetType]
 	push af
 	xor a
-	ld [H_AUTOBGTRANSFERENABLED], a
-	ld [hTilesetType], a ; no flower/water BG tile animations
+	ldh [hAutoBGTransferEnabled], a
+	ldh [hTilesetType], a ; no flower/water BG tile animations
 	call LoadCurrentMapView
 	call RunDefaultPaletteCommand
 	ld hl, wMapViewVRAMPointer
 	ld a, [hli]
 	ld h, [hl]
 	ld l, a
-	ld de, -2 * 32
+	ld de, -2 * BG_MAP_WIDTH
 	add hl, de
 	ld a, h
 	and $3
@@ -73,23 +73,23 @@ RedrawMapView:
 	ld a, h
 	ld [wBuffer + 1], a ; this copy of the address is not used
 	ld a, 2
-	ld [$ffbe], a
-	ld c, 9 ; number of rows of 2x2 tiles (this covers the whole screen)
+	ldh [hRedrawMapViewRowOffset], a
+	ld c, SCREEN_HEIGHT / 2 ; number of rows of 2x2 tiles (this covers the whole screen)
 .redrawRowLoop
 	push bc
 	push hl
 	push hl
 	ld hl, wTileMap - 2 * SCREEN_WIDTH
 	ld de, SCREEN_WIDTH
-	ld a, [$ffbe]
+	ldh a, [hRedrawMapViewRowOffset]
 .calcWRAMAddrLoop
 	add hl, de
 	dec a
 	jr nz, .calcWRAMAddrLoop
 	call CopyToRedrawRowOrColumnSrcTiles
 	pop hl
-	ld de, $20
-	ld a, [$ffbe]
+	ld de, BG_MAP_WIDTH
+	ldh a, [hRedrawMapViewRowOffset]
 	ld c, a
 .calcVRAMAddrLoop
 	add hl, de
@@ -98,13 +98,13 @@ RedrawMapView:
 	or $98
 	dec c
 	jr nz, .calcVRAMAddrLoop
-	ld [hRedrawRowOrColumnDest + 1], a
+	ldh [hRedrawRowOrColumnDest + 1], a
 	ld a, l
-	ld [hRedrawRowOrColumnDest], a
+	ldh [hRedrawRowOrColumnDest], a
 	ld a, REDRAW_ROW
-	ld [hRedrawRowOrColumnMode], a
+	ldh [hRedrawRowOrColumnMode], a
 	call DelayFrame
-	ld hl, $ffbe
+	ld hl, hRedrawMapViewRowOffset
 	inc [hl]
 	inc [hl]
 	pop hl
@@ -112,9 +112,9 @@ RedrawMapView:
 	dec c
 	jr nz, .redrawRowLoop
 	pop af
-	ld [hTilesetType], a
+	ldh [hTilesetType], a
 	pop af
-	ld [H_AUTOBGTRANSFERENABLED], a
+	ldh [hAutoBGTransferEnabled], a
 	ret
 
 CompareHLWithBC:
diff --git a/engine/overworld/wild_mons.asm b/engine/overworld/wild_mons.asm
index dae57f23..2593e0ec 100644
--- a/engine/overworld/wild_mons.asm
+++ b/engine/overworld/wild_mons.asm
@@ -1,4 +1,4 @@
-LoadWildData:
+LoadWildData::
 	ld hl, WildDataPointers
 	ld a, [wCurMap]
 
@@ -16,10 +16,10 @@ LoadWildData:
 	jr z, .NoGrassData ; if no grass data, skip to surfing data
 	push hl
 	ld de, wGrassMons ; otherwise, load grass data
-	ld bc, $0014
+	ld bc, $14
 	call CopyData
 	pop hl
-	ld bc, $0014
+	ld bc, $14
 	add hl, bc
 .NoGrassData
 	ld a, [hli]
@@ -27,7 +27,7 @@ LoadWildData:
 	and a
 	ret z        ; if no water data, we're done
 	ld de, wWaterMons  ; otherwise, load surfing data
-	ld bc, $0014
+	ld bc, $14
 	jp CopyData
 
-INCLUDE "data/wild_mons.asm"
+INCLUDE "data/wild/grass_water.asm"