Merge branch 'master' of https://github.com/pret/poketcg

11 files changed, 324 insertions, 166 deletions

diff --git a/src/constants/duel_constants.asm b/src/constants/duel_constants.asm
index d9b9e9c..943881b 100644
--- a/src/constants/duel_constants.asm
+++ b/src/constants/duel_constants.asm
@@ -165,6 +165,10 @@ NO_DAMAGE_OR_EFFECT_NSHIELD      EQU $05
 WEAKNESS   EQU 1
 RESISTANCE EQU 2
 
+; wEffectFailed constants
+EFFECT_FAILED_NO_EFFECT    EQU $01
+EFFECT_FAILED_UNSUCCESSFUL EQU $02
+
 ; Box message id's
 	const_def
 	const BOXMSG_PLAYERS_TURN
diff --git a/src/data/effect_commands.asm b/src/data/effect_commands.asm
index 6dc74ee..fa1bc81 100644
--- a/src/data/effect_commands.asm
+++ b/src/data/effect_commands.asm
@@ -109,8 +109,8 @@ ZubatLeechLifeEffectCommands:
 	db  $00
 
 BeedrillTwineedleEffectCommands:
-	dbw $03, $47f5
-	dbw $09, $47ed
+	dbw $03, Twineedle_MultiplierEffect
+	dbw $09, Twineedle_AIEffect
 	db  $00
 
 BeedrillPoisonStingEffectCommands:
@@ -127,8 +127,8 @@ ExeggcuteLeechSeedEffectCommands:
 	db  $00
 
 KoffingFoulGasEffectCommands:
-	dbw $03, $482a
-	dbw $09, $4822
+	dbw $03, FoulGas_PoisonOrConfusionEffect
+	dbw $09, FoulGas_AIEffect
 	db  $00
 
 MetapodStiffenEffectCommands:
@@ -158,19 +158,19 @@ ExeggutorTeleportEffectCommands:
 	db  $00
 
 ExeggutorBigEggsplosionEffectCommands:
-	dbw $03, $4944
-	dbw $09, $4925
+	dbw $03, BigEggsplosion_MultiplierEffect
+	dbw $09, BigEggsplosion_AIEffect
 	db  $00
 
 NidokingThrashEffectCommands:
-	dbw $03, $4973
-	dbw $04, $4982
-	dbw $09, $496b
+	dbw $03, Thrash_ModifierEffect
+	dbw $04, Func_2c982
+	dbw $09, Thrash_AIEffect
 	db  $00
 
 NidokingToxicEffectCommands:
-	dbw $03, $4994
-	dbw $09, $498c
+	dbw $03, Toxic_DoublePoisonEffect
+	dbw $09, Toxic_AIEffect
 	db  $00
 
 NidoqueenBoyfriendsEffectCommands:
diff --git a/src/engine/bank01.asm b/src/engine/bank01.asm
index 868d284..c7a31d0 100644
--- a/src/engine/bank01.asm
+++ b/src/engine/bank01.asm
@@ -2464,7 +2464,7 @@ DrawDuelHUDs: ; 503a (1:503a)
 	inc c
 	call CheckPrintPoisoned
 	inc c
-	call CheckPrintDoublePoisoned
+	call CheckPrintDoublePoisoned ; if double poisoned, print a second poison icon
 	call SwapTurn
 	lb de, 7, 0 ; coordinates for opponent's arena card name and info icons
 	lb bc, 3, 1 ; coordinates for opponent's attached energies and HP bar
@@ -2477,7 +2477,7 @@ DrawDuelHUDs: ; 503a (1:503a)
 	dec c
 	call CheckPrintPoisoned
 	dec c
-	call CheckPrintDoublePoisoned
+	call CheckPrintDoublePoisoned ; if double poisoned, print a second poison icon
 	call SwapTurn
 	ret
 ; 0x5093
@@ -5645,9 +5645,9 @@ CheckPrintPoisoned: ; 63bb (1:63bb)
 ; given a card's status in a, print the Poison symbol at bc if it's double poisoned
 CheckPrintDoublePoisoned: ; 63c7 (1:63c7)
 	push af
-	and DOUBLE_POISONED - POISONED
-	jr nz, CheckPrintPoisoned.poison ; double poison (print a second symbol)
-	jr CheckPrintPoisoned.print ; not double poisoned
+	and DOUBLE_POISONED & (POISONED ^ $ff)
+	jr nz, CheckPrintPoisoned.poison ; double poisoned (print SYM_POISONED)
+	jr CheckPrintPoisoned.print ; not double poisoned (print SYM_SPACE)
 ; 0x63ce
 
 ; given a card's status in a, print the Confusion, Sleep, or Paralysis symbol at bc
@@ -6117,7 +6117,7 @@ DuelDataToSave: ; 6729 (1:6729)
 ;	dw address, number_of_bytes_to_copy
 	dw wPlayerDuelVariables, wOpponentDuelVariables - wPlayerDuelVariables
 	dw wOpponentDuelVariables, wPlayerDeck - wOpponentDuelVariables
-	dw wPlayerDeck, wNameBuffer + $10 - wPlayerDeck
+	dw wPlayerDeck, wDuelTempList - wPlayerDeck
 	dw wWhoseTurn, wDuelTheme + $1 - wWhoseTurn
 	dw hWhoseTurn, $1
 	dw wRNG1, wRNGCounter + $1 - wRNG1
@@ -6824,12 +6824,12 @@ Func_6ba2: ; 6ba2 (1:6ba2)
 
 ; apply and/or refresh status conditions and other events that trigger between turns
 HandleBetweenTurnsEvents: ; 6baf (1:6baf)
-	call IsArenaPokemonAsleepOrDoublePoisoned
+	call IsArenaPokemonAsleepOrPoisoned
 	jr c, .something_to_handle
 	cp PARALYZED
 	jr z, .something_to_handle
 	call SwapTurn
-	call IsArenaPokemonAsleepOrDoublePoisoned
+	call IsArenaPokemonAsleepOrPoisoned
 	call SwapTurn
 	jr c, .something_to_handle
 	call DiscardAttachedPluspowers
@@ -6839,8 +6839,8 @@ HandleBetweenTurnsEvents: ; 6baf (1:6baf)
 	ret
 .something_to_handle
 	; either:
-	; 1. turn holder's arena Pokemon is paralyzed, asleep or double poisoned
-	; 2. non-turn holder's arena Pokemon is asleep or double poisoned
+	; 1. turn holder's arena Pokemon is paralyzed, asleep, poisoned or double poisoned
+	; 2. non-turn holder's arena Pokemon is asleep, poisoned or double poisoned
 	call Func_3b21
 	call ZeroObjectPositionsAndToggleOAMCopy
 	call EmptyScreen
@@ -6923,14 +6923,16 @@ DiscardAttachedDefenders: ; 6c56 (1:6c56)
 	jp MoveCardToDiscardPileIfInArena
 ; 0x6c68
 
-; return carry if the turn holder's arena Pokemon card is double poisoned or asleep.
+; return carry if the turn holder's arena Pokemon card is asleep, poisoned, or double poisoned.
 ; also, if confused, paralyzed, or asleep, return the status condition in a.
-IsArenaPokemonAsleepOrDoublePoisoned: ; 6c68 (1:6c68)
+IsArenaPokemonAsleepOrPoisoned: ; 6c68 (1:6c68)
 	ld a, DUELVARS_ARENA_CARD_STATUS
 	call GetTurnDuelistVariable
 	or a
 	ret z
-	and DOUBLE_POISONED
+	; note that POISONED | DOUBLE_POISONED is the same as just DOUBLE_POISONED ($c0)
+	; poison status masking is normally done with PSN_DBLPSN ($f0)
+	and POISONED | DOUBLE_POISONED
 	jr nz, .set_carry
 	ld a, [hl]
 	and CNF_SLP_PRZ
@@ -7189,9 +7191,9 @@ Func_6e49: ; 6e49 (1:6e49)
 	INCROM $6e49, $700a
 
 ; print one of the "There was no effect from" texts depending
-; on the value at wccf1 ($00 or a status condition constant)
+; on the value at wNoEffectFromStatus (NO_STATUS or a status condition constant)
 PrintThereWasNoEffectFromStatusText: ; 700a (1:700a)
-	ld a, [wccf1]
+	ld a, [wNoEffectFromStatus]
 	or a
 	jr nz, .status
 	ld hl, wLoadedMoveName
@@ -7413,18 +7415,21 @@ ClearNonTurnTemporaryDuelvars_CopyStatus: ; 7189 (1:7189)
 	ret
 ; 0x7195
 
+; update non-turn holder's DUELVARS_ARENA_CARD_LAST_TURN_DAMAGE
+; if wccef == 0: set to [wDealtDamage]
+; if wceef != 0: set to 0
 Func_7195: ; 7195 (1:7195)
 	ld a, DUELVARS_ARENA_CARD_LAST_TURN_DAMAGE
 	call GetNonTurnDuelistVariable
 	ld a, [wccef]
 	or a
-	jr nz, .asm_71a9
+	jr nz, .zero
 	ld a, [wDealtDamage]
 	ld [hli], a
-	ld a, [wccc0]
+	ld a, [wDealtDamage + 1]
 	ld [hl], a
 	ret
-.asm_71a9
+.zero
 	xor a
 	ld [hli], a
 	ld [hl], a
diff --git a/src/engine/bank02.asm b/src/engine/bank02.asm
index 38d74f7..a4a0f62 100644
--- a/src/engine/bank02.asm
+++ b/src/engine/bank02.asm
@@ -53,7 +53,7 @@ DuelCheckMenu_YourPlayArea: ; 8047 (2:4047)
 .draw
 	ld h, a
 	ld l, a
-	call DrawYourOrOppPlayArea_LoadTurnHolders
+	call DrawYourOrOppPlayAreaScreen
 
 	ld a, [wCheckMenuCursorYPosition]
 	sla a
@@ -93,11 +93,11 @@ DuelCheckMenu_YourPlayArea: ; 8047 (2:4047)
 	jr .draw
 
 .table ; 8098 (2:4098)
-	dw OpenDuelScreen_TurnHolderPlayArea
-	dw OpenDuelScreen_TurnHolderHand
-	dw OpenDuelScreen_TurnHolderDiscardPile
+	dw OpenYourOrOppPlayAreaScreen_TurnHolderPlayArea
+	dw OpenYourOrOppPlayAreaScreen_TurnHolderHand
+	dw OpenYourOrOppPlayAreaScreen_TurnHolderDiscardPile
 
-OpenDuelScreen_TurnHolderPlayArea: ; 809e (2:409e)
+OpenYourOrOppPlayAreaScreen_TurnHolderPlayArea: ; 809e (2:409e)
 	ldh a, [hWhoseTurn]
 	push af
 	bank1call OpenTurnHolderPlayAreaScreen
@@ -105,7 +105,7 @@ OpenDuelScreen_TurnHolderPlayArea: ; 809e (2:409e)
 	ldh [hWhoseTurn], a
 	ret
 
-OpenDuelScreen_NonTurnHolderPlayArea:
+OpenYourOrOppPlayAreaScreen_NonTurnHolderPlayArea:
 	ldh a, [hWhoseTurn]
 	push af
 	bank1call OpenNonTurnHolderPlayAreaScreen
@@ -113,7 +113,7 @@ OpenDuelScreen_NonTurnHolderPlayArea:
 	ldh [hWhoseTurn], a
 	ret
 
-OpenDuelScreen_TurnHolderHand:
+OpenYourOrOppPlayAreaScreen_TurnHolderHand:
 	ldh a, [hWhoseTurn]
 	push af
 	bank1call OpenTurnHolderHandScreen_Simple
@@ -121,7 +121,7 @@ OpenDuelScreen_TurnHolderHand:
 	ldh [hWhoseTurn], a
 	ret
 
-OpenDuelScreen_NonTurnHolderHand:
+OpenYourOrOppPlayAreaScreen_NonTurnHolderHand:
 	ldh a, [hWhoseTurn]
 	push af
 	bank1call OpenNonTurnHolderHandScreen_Simple
@@ -129,7 +129,7 @@ OpenDuelScreen_NonTurnHolderHand:
 	ldh [hWhoseTurn], a
 	ret
 
-OpenDuelScreen_TurnHolderDiscardPile:
+OpenYourOrOppPlayAreaScreen_TurnHolderDiscardPile:
 	ldh a, [hWhoseTurn]
 	push af
 	bank1call OpenTurnHolderDiscardPileScreen
@@ -137,7 +137,7 @@ OpenDuelScreen_TurnHolderDiscardPile:
 	ldh [hWhoseTurn], a
 	ret
 
-OpenDuelScreen_NonTurnHolderDiscardPile:
+OpenYourOrOppPlayAreaScreen_NonTurnHolderDiscardPile:
 	ldh a, [hWhoseTurn]
 	push af
 	bank1call OpenNonTurnHolderDiscardPileScreen
@@ -174,7 +174,7 @@ DuelCheckMenu_OppPlayArea: ; 80da (2:40da)
 	ld h, a
 
 .cursor
-	call DrawYourOrOppPlayArea_LoadTurnHolders
+	call DrawYourOrOppPlayAreaScreen
 
 ; convert cursor position and
 ; store it in wYourOrOppPlayAreaLastCursorPosition
@@ -230,9 +230,9 @@ DuelCheckMenu_OppPlayArea: ; 80da (2:40da)
 	jr .turns
 
 .table
-	dw OpenDuelScreen_NonTurnHolderPlayArea
-	dw OpenDuelScreen_NonTurnHolderHand
-	dw OpenDuelScreen_NonTurnHolderDiscardPile
+	dw OpenYourOrOppPlayAreaScreen_NonTurnHolderPlayArea
+	dw OpenYourOrOppPlayAreaScreen_NonTurnHolderHand
+	dw OpenYourOrOppPlayAreaScreen_NonTurnHolderDiscardPile
 
 CheckMenuData: ; (2:4158)
 	textitem  2, 14, InPlayAreaText
@@ -384,21 +384,21 @@ YourOrOppPlayAreaArrowPositions_OpponentDiscardPile:
 	db 0, 8
 	db $ff
 
-; loads tiles and icons to display your/opp play area
+; loads tiles and icons to display Your Play Area / Opp. Play Area screen,
 ; and draws the screen according to the turn player
-; h = turn holder 1
-; l = turn holder 2
-DrawYourOrOppPlayArea_LoadTurnHolders: ; 8209 (2:4209)
+; input: h -> [wCheckMenuPlayAreaWhichDuelist] and l -> [wCheckMenuPlayAreaWhichLayout]
+DrawYourOrOppPlayAreaScreen: ; 8209 (2:4209)
 ; loads the turn holders
 	ld a, h
-	ld [wTurnHolder1], a
+	ld [wCheckMenuPlayAreaWhichDuelist], a
 	ld a, l
-	ld [wTurnHolder2], a
+	ld [wCheckMenuPlayAreaWhichLayout], a
 ; fallthrough
 
 ; loads tiles and icons to display Your Play Area / Opp. Play Area screen,
 ; and draws the screen according to the turn player
-_DrawYourOrOppPlayArea: ; 8211 (2:4211)
+; input: [wCheckMenuPlayAreaWhichDuelist] and [wCheckMenuPlayAreaWhichLayout]
+_DrawYourOrOppPlayAreaScreen: ; 8211 (2:4211)
 	xor a
 	ld [wTileMapFill], a
 	call ZeroObjectPositions
@@ -413,7 +413,7 @@ _DrawYourOrOppPlayArea: ; 8211 (2:4211)
 	call LoadSymbolsFont
 	call LoadDeckAndDiscardPileIcons
 
-	ld a, [wTurnHolder1]
+	ld a, [wCheckMenuPlayAreaWhichDuelist]
 	cp PLAYER_TURN
 	jr nz, .opp_turn1
 
@@ -441,7 +441,7 @@ _DrawYourOrOppPlayArea: ; 8211 (2:4211)
 	ldh a, [hWhoseTurn]
 	cp PLAYER_TURN
 	jr nz, .opp_turn2
-	ld a, [wTurnHolder1]
+	ld a, [wCheckMenuPlayAreaWhichDuelist]
 	cp PLAYER_TURN
 	jr nz, .swap
 .opp_turn2
@@ -453,9 +453,9 @@ _DrawYourOrOppPlayArea: ; 8211 (2:4211)
 	call SwapTurn
 
 .draw
-	ld a, [wTurnHolder1]
+	ld a, [wCheckMenuPlayAreaWhichDuelist]
 	ld b, a
-	ld a, [wTurnHolder2]
+	ld a, [wCheckMenuPlayAreaWhichLayout]
 	cp b
 	jr nz, .not_equal
 
@@ -468,7 +468,8 @@ _DrawYourOrOppPlayArea: ; 8211 (2:4211)
 	call DrawPlayArea_BenchCards
 	xor a
 	call DrawYourOrOppPlayArea_Icons
-	jr .lcd
+	jr .done
+
 .not_equal
 	ld hl, PrizeCardsCoordinateData_YourOrOppPlayArea.opponent
 	call DrawPlayArea_PrizeCards
@@ -480,14 +481,14 @@ _DrawYourOrOppPlayArea: ; 8211 (2:4211)
 	ld a, $01
 	call DrawYourOrOppPlayArea_Icons
 
-.lcd
+.done
 	call EnableLCD
 	ret
 
 Func_82b6: ; 82b6 (2:42b6)
-	ld a, [wTurnHolder1]
+	ld a, [wCheckMenuPlayAreaWhichDuelist]
 	ld b, a
-	ld a, [wTurnHolder2]
+	ld a, [wCheckMenuPlayAreaWhichLayout]
 	cp b
 	jr nz, .not_equal
 
@@ -502,7 +503,7 @@ Func_82b6: ; 82b6 (2:42b6)
 
 ; loads tiles and icons to display the In Play Area screen,
 ; and draws the screen
-_DrawInPlayArea: ; 82ce (2:42ce)
+DrawInPlayAreaScreen: ; 82ce (2:42ce)
 	xor a
 	ld [wTileMapFill], a
 	call ZeroObjectPositions
@@ -524,8 +525,8 @@ _DrawInPlayArea: ; 82ce (2:42ce)
 
 ; reset turn holders
 	ldh a, [hWhoseTurn]
-	ld [wTurnHolder1], a
-	ld [wTurnHolder2], a
+	ld [wCheckMenuPlayAreaWhichDuelist], a
+	ld [wCheckMenuPlayAreaWhichLayout], a
 
 ; player prize cards
 	ld hl, PrizeCardsCoordinateData_InPlayArea.player
@@ -541,7 +542,7 @@ _DrawInPlayArea: ; 82ce (2:42ce)
 
 	call SwapTurn
 	ldh a, [hWhoseTurn]
-	ld [wTurnHolder1], a
+	ld [wCheckMenuPlayAreaWhichDuelist], a
 	call SwapTurn
 
 ; opponent prize cards
@@ -575,8 +576,8 @@ _DrawPlayersPrizeAndBenchCards: ; 833c (2:433c)
 
 ; player cards
 	ld a, PLAYER_TURN
-	ld [wTurnHolder1], a
-	ld [wTurnHolder2], a
+	ld [wCheckMenuPlayAreaWhichDuelist], a
+	ld [wCheckMenuPlayAreaWhichLayout], a
 	ld hl, PrizeCardsCoordinateData_2.player
 	call DrawPlayArea_PrizeCards
 	lb de, 5, 10 ; coordinates
@@ -585,7 +586,7 @@ _DrawPlayersPrizeAndBenchCards: ; 833c (2:433c)
 
 ; opponent cards
 	ld a, OPPONENT_TURN
-	ld [wTurnHolder1], a
+	ld [wCheckMenuPlayAreaWhichDuelist], a
 	ld hl, PrizeCardsCoordinateData_2.opponent
 	call DrawPlayArea_PrizeCards
 	lb de, 1, 0 ; coordinates
@@ -594,21 +595,21 @@ _DrawPlayersPrizeAndBenchCards: ; 833c (2:433c)
 	ret
 
 ; draws the active card gfx at coordinates de
-; of the player (or opponent) depending on wTurnHolder1
+; of the player (or opponent) depending on wCheckMenuPlayAreaWhichDuelist
 ; input:
 ; de = coordinates
 DrawYourOrOppPlayArea_ActiveCardGfx: ; 837e (2:437e)
 	push de
 	ld a, DUELVARS_ARENA_CARD
 	ld l, a
-	ld a, [wTurnHolder1]
+	ld a, [wCheckMenuPlayAreaWhichDuelist]
 	ld h, a
 	ld a, [hl]
 	cp -1
 	jr z, .no_pokemon
 
 	ld d, a
-	ld a, [wTurnHolder1]
+	ld a, [wCheckMenuPlayAreaWhichDuelist]
 	ld b, a
 	ldh a, [hWhoseTurn]
 	cp b
@@ -623,7 +624,7 @@ DrawYourOrOppPlayArea_ActiveCardGfx: ; 837e (2:437e)
 	call SwapTurn
 
 .draw
-	lb de, $8a, $00 ; destination offset of loaded gfx
+	ld de, v0Tiles1 + $20 tiles ; destination offset of loaded gfx
 	ld hl, wLoadedCard1Gfx
 	ld a, [hli]
 	ld h, [hl]
@@ -734,13 +735,13 @@ DrawInPlayArea_ActiveCardGfx: ; 83cc (2:43cc)
 	ret
 
 ; draws prize cards depending on the turn
-; loaded in wTurnHolder1
+; loaded in wCheckMenuPlayAreaWhichDuelist
 ; input:
 ; hl = pointer to coordinates
 DrawPlayArea_PrizeCards: ; 8464 (2:4464)
 	push hl
 	call GetDuelInitialPrizesUpperBitsSet
-	ld a, [wTurnHolder1]
+	ld a, [wCheckMenuPlayAreaWhichDuelist]
 	ld h, a
 	ld l, DUELVARS_PRIZES
 	ld a, [hl]
@@ -869,15 +870,15 @@ GetDuelInitialPrizesUpperBitsSet: ; 84fc (2:44fc)
 	ld [wDuelInitialPrizesUpperBitsSet], a
 	ret
 
-; draws filled and empty bench slots depending on the turn loaded in wTurnHolder1
-; if wTurnHolder1 is different from wTurnHolder2 adjusts coordinates of the bench slots
+; draws filled and empty bench slots depending on the turn loaded in wCheckMenuPlayAreaWhichDuelist
+; if wCheckMenuPlayAreaWhichDuelist is different from wCheckMenuPlayAreaWhichLayout adjusts coordinates of the bench slots
 ; input:
 ; de = coordinates to draw bench
 ; c  = spacing between slots
 DrawPlayArea_BenchCards: ; 8511 (2:4511)
-	ld a, [wTurnHolder2]
+	ld a, [wCheckMenuPlayAreaWhichLayout]
 	ld b, a
-	ld a, [wTurnHolder1]
+	ld a, [wCheckMenuPlayAreaWhichDuelist]
 	cp b
 	jr z, .skip
 
@@ -896,7 +897,7 @@ DrawPlayArea_BenchCards: ; 8511 (2:4511)
 	ld c, a
 	; c = $ff - c + 1
 
-	ld a, [wTurnHolder1]
+	ld a, [wCheckMenuPlayAreaWhichDuelist]
 .skip
 	ld h, a
 	ld l, DUELVARS_NUMBER_OF_POKEMON_IN_PLAY_AREA
@@ -952,7 +953,7 @@ DrawPlayArea_BenchCards: ; 8511 (2:4511)
 	jr .loop_1
 
 .done
-	ld a, [wTurnHolder1]
+	ld a, [wCheckMenuPlayAreaWhichDuelist]
 	ld h, a
 	ld l, DUELVARS_NUMBER_OF_POKEMON_IN_PLAY_AREA
 	ld b, [hl]
@@ -1007,7 +1008,7 @@ DrawYourOrOppPlayArea_Icons: ; 85aa (2:45aa)
 
 .draw
 ; hand icon and value
-	ld a, [wTurnHolder1]
+	ld a, [wCheckMenuPlayAreaWhichDuelist]
 	ld d, a
 	ld e, DUELVARS_NUMBER_OF_CARDS_IN_HAND
 	ld a, [de]
@@ -1016,7 +1017,7 @@ DrawYourOrOppPlayArea_Icons: ; 85aa (2:45aa)
 	call DrawPlayArea_HandText
 
 ; deck icon and value
-	ld a, [wTurnHolder1]
+	ld a, [wCheckMenuPlayAreaWhichDuelist]
 	ld d, a
 	ld e, DUELVARS_NUMBER_OF_CARDS_NOT_IN_DECK
 	ld a, [de]
@@ -1028,7 +1029,7 @@ DrawYourOrOppPlayArea_Icons: ; 85aa (2:45aa)
 	call DrawPlayArea_IconWithValue
 
 ; discard pile icon and value
-	ld a, [wTurnHolder1]
+	ld a, [wCheckMenuPlayAreaWhichDuelist]
 	ld d, a
 	ld e, DUELVARS_NUMBER_OF_CARDS_IN_DISCARD_PILE
 	ld a, [de]
@@ -1386,7 +1387,7 @@ Func_8764: ; 8764 (2:4764)
 	ldh a, [hWhoseTurn]
 	ld h, a
 	ld l, a
-	call DrawYourOrOppPlayArea_LoadTurnHolders
+	call DrawYourOrOppPlayAreaScreen
 
 .swap
 	ld a, [$ce56]
@@ -1419,7 +1420,7 @@ Func_8764: ; 8764 (2:4764)
 	jp nz, Func_8883 ; jump if not first option
 
 ; hCurMenuItem = 0
-	ld a, [wTurnHolder1]
+	ld a, [wCheckMenuPlayAreaWhichDuelist]
 	ld b, a
 	ldh a, [hWhoseTurn]
 	cp b
@@ -1428,7 +1429,7 @@ Func_8764: ; 8764 (2:4764)
 ; switch the play area to draw
 	ld h, a
 	ld l, a
-	call DrawYourOrOppPlayArea_LoadTurnHolders
+	call DrawYourOrOppPlayAreaScreen
 	xor a
 	ld [$ce56], a
 
@@ -1562,7 +1563,7 @@ Func_8855:
 	ret
 
 Func_8883: ; 8883 (2:4883)
-	ld a, [wTurnHolder1]
+	ld a, [wCheckMenuPlayAreaWhichDuelist]
 	ld b, a
 	ldh a, [hWhoseTurn]
 	cp b
@@ -1578,7 +1579,7 @@ Func_8883: ; 8883 (2:4883)
 
 .draw
 	ld h, a
-	call DrawYourOrOppPlayArea_LoadTurnHolders
+	call DrawYourOrOppPlayAreaScreen
 
 .text
 	call DrawWideTextBox
diff --git a/src/engine/bank06.asm b/src/engine/bank06.asm
index fbf9016..cb1b0a9 100644
--- a/src/engine/bank06.asm
+++ b/src/engine/bank06.asm
@@ -158,7 +158,7 @@ Func_180d5: ; 180d5 (6:40d5)
 .asm_006_40da
 	xor a
 	ld [wCheckMenuCursorBlinkCounter], a
-	farcall _DrawInPlayArea
+	farcall DrawInPlayAreaScreen
 	call EnableLCD
 	call IsClairvoyanceActive
 	jr c, .asm_006_40ef
@@ -1122,7 +1122,7 @@ Func_006_50fb: ; 190fb (6:50fb)
 	ld a, [wWhoseTurn]
 	ld l, a
 .asm_006_5127
-	call DrawYourOrOppPlayArea
+	call DrawYourOrOppPlayAreaScreen_Bank0
 	pop af
 	ld [wDuelDisplayedScreen], a
 .asm_006_512e
diff --git a/src/engine/effect_functions.asm b/src/engine/effect_functions.asm
index b3c707b..c8d8f24 100644
--- a/src/engine/effect_functions.asm
+++ b/src/engine/effect_functions.asm
@@ -7,6 +7,7 @@ PoisonEffect: ; 2c007 (b:4007)
 	lb bc, CNF_SLP_PRZ, POISONED
 	jr ApplyStatusEffect
 
+DoublePoisonEffect: ; 2c00c (b:400c)
 	lb bc, CNF_SLP_PRZ, DOUBLE_POISONED
 	jr ApplyStatusEffect
 
@@ -56,7 +57,7 @@ ApplyStatusEffect:
 
 .cant_induce_status
 	ld a, c
-	ld [wccf1], a
+	ld [wNoEffectFromStatus], a
 	call SetNoEffectFromStatus
 	or a
 	ret
@@ -118,49 +119,50 @@ Func_2c08c:
 ; 0x2c09c
 
 SetNoEffectFromStatus: ; 2c09c (b:409c)
-	ld a, $1
-	ld [wcced], a
+	ld a, EFFECT_FAILED_NO_EFFECT
+	ld [wEffectFailed], a
 	ret
 ; 0x2c0a2
 
 SetWasUnsuccessful: ; 2c0a2 (b:40a2)
-	ld a, $2
-	ld [wcced], a
+	ld a, EFFECT_FAILED_UNSUCCESSFUL
+	ld [wEffectFailed], a
 	ret
 ; 0x2c0a8
 
 	INCROM $2c0a8, $2c0d4
 
 ; Sets some flags for AI use
-; if target double poisoned
-; 	[wccbb]   <- [wDamage]
-; 	[wccbc]   <- [wDamage]
+; if target poisoned
+; 	[wAIMinDamage] <- [wDamage]
+; 	[wAIMaxDamage] <- [wDamage]
 ; else
-; 	[wccbb]   <- [wDamage] + d
-; 	[wccbc]   <- [wDamage] + e
-; 	[wDamage] <- [wDamage] + a
+; 	[wAIMinDamage] <- [wDamage] + d
+; 	[wAIMaxDamage] <- [wDamage] + e
+; 	[wDamage]      <- [wDamage] + a
 Func_2c0d4: ; 2c0d4 (b:40d4)
 	push af
 	ld a, DUELVARS_ARENA_CARD_STATUS
 	call GetNonTurnDuelistVariable
-	and DOUBLE_POISONED
-	jr z, .not_double_poisoned
+	and POISONED | DOUBLE_POISONED
+	jr z, Func_2c0e9.skip_push_af
 	pop af
 	ld a, [wDamage]
-	ld [wccbb], a
-	ld [wccbc], a
+	ld [wAIMinDamage], a
+	ld [wAIMaxDamage], a
 	ret
 
+Func_2c0e9: ; 2c0e9 (b:40e9)
 	push af
 
-.not_double_poisoned
+.skip_push_af
 	ld hl, wDamage
 	ld a, [hl]
 	add d
-	ld [wccbb], a
+	ld [wAIMinDamage], a
 	ld a, [hl]
 	add e
-	ld [wccbc], a
+	ld [wAIMaxDamage], a
 	pop af
 	add [hl]
 	ld [hl], a
@@ -168,17 +170,17 @@ Func_2c0d4: ; 2c0d4 (b:40d4)
 ; 0x2c0fb
 
 ; Sets some flags for AI use
-; [wDamage] <- a
-; [wccbb]   <- d
-; [wccbc]   <- e
+; [wDamage]      <- a
+; [wAIMinDamage] <- d
+; [wAIMaxDamage] <- e
 Func_2c0fb: ; 2c0fb (b:40fb)
 	ld [wDamage], a
 	xor a
 	ld [wDamage + 1], a
 	ld a, d
-	ld [wccbb], a
+	ld [wAIMinDamage], a
 	ld a, e
-	ld [wccbc], a
+	ld [wAIMaxDamage], a
 	ret
 ; 0x2c10b
 
@@ -219,14 +221,24 @@ ApplySubstatus2ToDefendingCard: ; 2c149 (b:4149)
 	ret
 ; 0x2c166
 
-	INCROM $2c166, $2c6f0
+Func_2c166: ; 2c166 (b:4166)
+	ld [wDamage], a
+	ld [wAIMinDamage], a
+	ld [wAIMaxDamage], a
+	xor a
+	ld [wDamage + 1], a
+	ret
+; 0x2c174
+
+	INCROM $2c174, $2c6f0
 
 SpitPoison_AIEffect: ; 2c6f0 (b:46f0)
-	ld a, $5
-	lb de, $0, $a
+	ld a, 5
+	lb de, 0, 10
 	jp Func_2c0fb
 ; 0x2c6f8
 
+; If heads, defending Pokemon becomes poisoned
 SpitPoison_Poison50PercentEffect: ; 2c6f8 (b:46f8)
 	ldtx de, PoisonCheckText
 	call TossCoin_BankB
@@ -240,19 +252,20 @@ SpitPoison_Poison50PercentEffect: ; 2c6f8 (b:46f8)
 	INCROM $2c70a, $2c730
 
 PoisonFang_AIEffect: ; 2c730 (b:4730)
-	ld a, $a
-	lb de, $a, $a
+	ld a, 10
+	lb de, 10, 10
 	jp Func_2c0d4
 ; 0x2c738
 
 WeepinbellPoisonPowder_AIEffect: ; 2c738 (b:4738)
-	ld a, $5
-	lb de, $0, $a
+	ld a, 5
+	lb de, 0, 10
 	jp Func_2c0d4
 ; 0x2c740
 
 	INCROM $2c740, $2c77e
 
+; If heads, defending Pokemon can't retreat next turn
 AcidEffect: ; 2c77e (b:477e)
 	ldtx de, AcidCheckText
 	call TossCoin_BankB
@@ -263,12 +276,12 @@ AcidEffect: ; 2c77e (b:477e)
 ; 0x2c78b
 
 GloomPoisonPowder_AIEffect: ; 2c78b (b:478b)
-	ld a, $a
-	lb de, $a, $a
+	ld a, 10
+	lb de, 10, 10
 	jp Func_2c0d4
 ; 0x2c793
 
-; confuses both the target and the user
+; Defending Pokemon and user become confused
 FoulOdorEffect: ; 2c793 (b:4793)
 	call ConfusionEffect
 	call SwapTurn
@@ -277,6 +290,7 @@ FoulOdorEffect: ; 2c793 (b:4793)
 	ret
 ; 0x2c7a0
 
+; If heads, prevent all damage done to user next turn
 KakunaStiffenEffect: ; 2c7a0 (b:47a0)
 	ldtx de, IfHeadsNoDamageNextTurnText
 	call TossCoin_BankB
@@ -289,13 +303,14 @@ KakunaStiffenEffect: ; 2c7a0 (b:47a0)
 ; 0x2c7b4
 
 KakunaPoisonPowder_AIEffect: ; 2c7b4 (b:47b4)
-	ld a, $5
-	lb de, $0, $a
+	ld a, 5
+	lb de, 0, 10
 	jp Func_2c0d4
 ; 0x2c7bc
 
 	INCROM $2c7bc, $2c7d0
 
+; During your next turn, double damage
 SwordsDanceEffect: ; 2c7d0 (b:47d0)
 	ld a, [wTempTurnDuelistCardID]
 	cp SCYTHER
@@ -305,15 +320,54 @@ SwordsDanceEffect: ; 2c7d0 (b:47d0)
 	ret
 ; 0x2c7dc
 
+; If heads, defending Pokemon becomes confused
 ZubatSupersonicEffect: ; 2c7dc (b:47dc)
 	call Confusion50PercentEffect
 	call nc, SetNoEffectFromStatus
 	ret
 ; 0x2c7e3
 
-	INCROM $2c7e3, $2c836
+	INCROM $2c7e3, $2c7ed
+
+Twineedle_AIEffect: ; 2c7ed (b:47ed)
+	ld a, 30
+	lb de, 0, 60
+	jp Func_2c0fb
+; 0x2c7f5
+
+; Flip 2 coins; deal 30x number of heads
+Twineedle_MultiplierEffect: ; 2c7f5 (b:47f5)
+	ld hl, 30
+	call LoadTxRam3
+	ldtx de, DamageCheckIfHeadsXDamageText
+	ld a, 2
+	call TossCoinATimes_BankB
+	ld e, a
+	add a
+	add e
+	call ATimes10
+	call Func_2c166
+	ret
+; 0x2c80d
+
+	INCROM $2c80d, $2c822
+
+FoulGas_AIEffect: ; 2c822 (b:4822)
+	ld a, 5
+	lb de, 0, 10
+	jp Func_2c0e9
+; 0x2c82a
+
+; If heads, defending Pokemon becomes poisoned. If tails, defending Pokemon becomes confused
+FoulGas_PoisonOrConfusionEffect: ; 2c82a (b:482a)
+	ldtx de, PoisonedIfHeadsConfusedIfTailsText
+	call TossCoin_BankB
+	jp c, PoisonEffect
+	jp ConfusionEffect
+; 0x2c836
 
 ; an exact copy of KakunaStiffenEffect
+; If heads, prevent all damage done to user next turn
 MetapodStiffenEffect: ; 2c836 (b:4836)
 	ldtx de, IfHeadsNoDamageNextTurnText
 	call TossCoin_BankB
@@ -325,4 +379,92 @@ MetapodStiffenEffect: ; 2c836 (b:4836)
 	ret
 ; 0x2c84a
 
-	INCROM $2c84a, $30000
+	INCROM $2c84a, $2c925
+
+BigEggsplosion_AIEffect: ; 2c925 (b:4925)
+	ldh a, [hTempPlayAreaLocation_ff9d]
+	ld e, a
+	call GetPlayAreaCardAttachedEnergies
+	ld a, [wTotalAttachedEnergies]
+	call SetDamageToATimes20
+	inc h
+	jr nz, .capped
+	ld l, 255
+.capped
+	ld a, l
+	ld [wAIMaxDamage], a
+	srl a
+	ld [wDamage], a
+	xor a
+	ld [wAIMinDamage], a
+	ret
+; 0x2c944
+
+; Flip coins equal to attached energies; deal 20x number of heads
+BigEggsplosion_MultiplierEffect: ; 2c944 (b:4944)
+	ld e, PLAY_AREA_ARENA
+	call GetPlayAreaCardAttachedEnergies
+	ld hl, 20
+	call LoadTxRam3
+	ld a, [wTotalAttachedEnergies]
+	ldtx de, DamageCheckIfHeadsXDamageText
+	call TossCoinATimes_BankB
+;	fallthrough
+
+; set damage to 20*a. Also return result in hl
+SetDamageToATimes20: ; 2c958 (b:4958)
+	ld l, a
+	ld h, $00
+	ld e, l
+	ld d, h
+	add hl, hl
+	add hl, hl
+	add hl, de
+	add hl, hl
+	add hl, hl
+	ld a, l
+	ld [wDamage], a
+	ld a, h
+	ld [wDamage + 1], a
+	ret
+; 0x2c96b
+
+Thrash_AIEffect: ; 2c96b (b:496b)
+	ld a, 35
+	lb de, 30, 40
+	jp Func_2c0fb
+; 0x2c973
+
+; If heads 10 more damage; if tails, 10 damage to itself
+Thrash_ModifierEffect: ; 2c973 (b:4973)
+	ldtx de, IfHeadPlus10IfTails10ToYourselfText
+	call TossCoin_BankB
+	ldh [hTemp_ffa0], a
+	ret nc
+	ld a, 10
+	call AddToDamage
+	ret
+; 0x2c982
+
+Func_2c982: ; 2c982 (b:4982)
+	ldh a, [hTemp_ffa0]
+	or a
+	ret nz
+	ld a, 10
+	call Func_1955
+	ret
+; 0x2c98c
+
+Toxic_AIEffect: ; 2c98c (b:498c)
+	ld a, 20
+	lb de, 20, 20
+	jp Func_2c0e9
+; 0x2c994
+
+; Defending Pokémon becomes poisoned, but takes 20 damage (double poisoned)
+Toxic_DoublePoisonEffect: ; 2c994 (b:4994)
+	call DoublePoisonEffect
+	ret
+; 0x2c998
+
+	INCROM $2c998, $30000
diff --git a/src/engine/home.asm b/src/engine/home.asm
index 40a1f85..ff07a17 100644
--- a/src/engine/home.asm
+++ b/src/engine/home.asm
@@ -4453,11 +4453,11 @@ Func_16f6: ; 16f6 (0:16f6)
 	xor a
 	ld [wccec], a
 	ld [wEffectFunctionsFeedbackIndex], a
-	ld [wcced], a
+	ld [wEffectFailed], a
 	ld [wIsDamageToSelf], a
 	ld [wccef], a
 	ld [wccf0], a
-	ld [wccf1], a
+	ld [wNoEffectFromStatus], a
 	bank1call ClearNonTurnTemporaryDuelvars_CopyStatus
 	ret
 
@@ -5175,10 +5175,10 @@ Func_1bb4: ; 1bb4 (0:1bb4)
 	call ExchangeRNG
 	ret
 
-; prints one of the ThereWasNoEffectFrom*Text if wcced contains $1,
-; and WasUnsuccessfulText if wcced contains $2
+; prints one of the ThereWasNoEffectFrom*Text if wEffectFailed contains EFFECT_FAILED_NO_EFFECT,
+; and prints WasUnsuccessfulText if wEffectFailed contains EFFECT_FAILED_UNSUCCESSFUL
 Func_1bca: ; 1bca (0:1bca)
-	ld a, [wcced]
+	ld a, [wEffectFailed]
 	or a
 	ret z
 	cp $1
@@ -9303,16 +9303,22 @@ Func_30a6: ; 30a6 (0:30a6)
 	call BankswitchROM
 	ret
 
-DrawYourOrOppPlayArea: ; 30bc (0:30bc)
+; loads tiles and icons to display Your Play Area / Opp. Play Area screen,
+; and draws the screen according to the turn player
+; input: h -> [wCheckMenuPlayAreaWhichDuelist] and l -> [wCheckMenuPlayAreaWhichLayout]
+; similar to DrawYourOrOppPlayArea (bank 2) except it also draws a wide text box.
+; this is because bank 2's DrawYourOrOppPlayArea is supposed to come from the Check Menu,
+; so the text box is always already there.
+DrawYourOrOppPlayAreaScreen_Bank0: ; 30bc (0:30bc)
 	ld a, h
-	ld [wTurnHolder1], a
+	ld [wCheckMenuPlayAreaWhichDuelist], a
 	ld a, l
-	ld [wTurnHolder2], a
+	ld [wCheckMenuPlayAreaWhichLayout], a
 	ldh a, [hBankROM]
 	push af
-	ld a, BANK(_DrawYourOrOppPlayArea)
+	ld a, BANK(_DrawYourOrOppPlayAreaScreen)
 	call BankswitchROM
-	call _DrawYourOrOppPlayArea
+	call _DrawYourOrOppPlayAreaScreen
 	call DrawWideTextBox
 	pop af
 	call BankswitchROM
diff --git a/src/text/text1.asm b/src/text/text1.asm
index e7b0fe4..8789758 100644
--- a/src/text/text1.asm
+++ b/src/text/text1.asm
@@ -1093,7 +1093,7 @@ Text00e8: ; 37d92 (d:7d92)
 	line "10 damage for each Heads!!!"
 	done
 
-Text00e9: ; 37dc9 (d:7dc9)
+IfHeadPlus10IfTails10ToYourselfText: ; 37dc9 (d:7dc9)
 	text "If Heads, + 10 damage!"
 	line "If Tails, +10 damage to yourself!"
 	done
@@ -1142,12 +1142,12 @@ Text00f2: ; 37f9a (d:7f9a)
 	text "Damage check"
 	done
 
-Text00f3: ; 37fa8 (d:7fa8)
+DamageCheckIfHeadsPlusDamageText: ; 37fa8 (d:7fa8)
 	text "Damage check!"
 	line "If Heads, +<RAMNUM> damage!!"
 	done
 
-Text00f4: ; 37fcd (d:7fcd)
+DamageCheckIfHeadsXDamageText: ; 37fcd (d:7fcd)
 	text "Damage check!"
 	line "If Heads, x <RAMNUM> damage!!"
 	done
diff --git a/src/text/text2.asm b/src/text/text2.asm
index 78fb6f9..8dac791 100644
--- a/src/text/text2.asm
+++ b/src/text/text2.asm
@@ -22,7 +22,7 @@ PokemonsSleepCheckText: ; 380db (e:40db)
 	text "<RAMTEXT>'s Sleep check."
 	done
 
-Text00fa: ; 380ed (e:40ed)
+PoisonedIfHeadsConfusedIfTailsText: ; 380ed (e:40ed)
 	text "Opponent is Poisoned if Heads,"
 	line "and Confused if Tails."
 	done
diff --git a/src/text/text_offsets.asm b/src/text/text_offsets.asm
index f1ca193..6e03ba2 100644
--- a/src/text/text_offsets.asm
+++ b/src/text/text_offsets.asm
@@ -234,7 +234,7 @@ TextOffsets:: ; 34000 (d:4000)
 	textpointer Text00e6                                 ; 0x00e6
 	textpointer Text00e7                                 ; 0x00e7
 	textpointer Text00e8                                 ; 0x00e8
-	textpointer Text00e9                                 ; 0x00e9
+	textpointer IfHeadPlus10IfTails10ToYourselfText                                 ; 0x00e9
 	textpointer Text00ea                                 ; 0x00ea
 	textpointer Text00eb                                 ; 0x00eb
 	textpointer Text00ec                                 ; 0x00ec
@@ -244,14 +244,14 @@ TextOffsets:: ; 34000 (d:4000)
 	textpointer Text00f0                                 ; 0x00f0
 	textpointer IfHeadsNoDamageNextTurnText              ; 0x00f1
 	textpointer Text00f2                                 ; 0x00f2
-	textpointer Text00f3                                 ; 0x00f3
-	textpointer Text00f4                                 ; 0x00f4
+	textpointer DamageCheckIfHeadsPlusDamageText                                 ; 0x00f3
+	textpointer DamageCheckIfHeadsXDamageText                                 ; 0x00f4
 	textpointer AcidCheckText                            ; 0x00f5
 	textpointer TransparencyCheckText                    ; 0x00f6
 	textpointer ConfusionCheckDamageText                 ; 0x00f7
 	textpointer ConfusionCheckRetreatText                ; 0x00f8
 	textpointer PokemonsSleepCheckText                   ; 0x00f9
-	textpointer Text00fa                                 ; 0x00fa
+	textpointer PoisonedIfHeadsConfusedIfTailsText                                 ; 0x00fa
 	textpointer Text00fb                                 ; 0x00fb
 	textpointer Text00fc                                 ; 0x00fc
 	textpointer AttackUnsuccessfulText                   ; 0x00fd
diff --git a/src/wram.asm b/src/wram.asm
index a06be8c..caba9d1 100644
--- a/src/wram.asm
+++ b/src/wram.asm
@@ -190,9 +190,7 @@ wPlayerArenaCardDisabledMoveIndex:: ; c2f2
 
 ; damage taken the last time the opponent attacked (0 if no damage)
 wPlayerArenaCardLastTurnDamage:: ; c2f3
-	ds $1
-
-	ds $1
+	ds $2
 
 ; status condition received the last time the opponent attacked (0 if none)
 wPlayerArenaCardLastTurnStatus:: ; c2f5
@@ -333,9 +331,7 @@ wOpponentArenaCardDisabledMoveIndex:: ; c3f2
 	ds $1
 
 wOpponentArenaCardLastTurnDamage:: ; c3f3
-	ds $1
-
-	ds $1
+	ds $2
 
 wOpponentArenaCardLastTurnStatus:: ; c3f5
 	ds $1
@@ -919,24 +915,25 @@ wLoadedMove:: ; cca6
 	move_data_struct wLoadedMove
 
 ; the damage field of an used move is loaded here
+; doubles as "wAIAverageDamage" when complementing wAIMinDamage and wAIMaxDamage
+; little-endian
 wDamage:: ; ccb9
 	ds $2
 
-; wccbb and wccbc appear to be used for AI scoring
-wccbb:: ; ccbb
+; wAIMinDamage and wAIMaxDamage appear to be used for AI scoring
+; they are updated with the minimum (or floor) damage of the current move
+; and with the maximum (or ceiling) damage of the current move
+wAIMinDamage:: ; ccbb
 	ds $1
 
-wccbc:: ; ccbc
+wAIMaxDamage:: ; ccbc
 	ds $1
 
 	ds $2
 
 ; damage dealt by an attack to a target
 wDealtDamage:: ; ccbf
-	ds $1
-
-wccc0:: ; ccc0
-	ds $1
+	ds $2
 
 ; WEAKNESS and RESISTANCE flags	for a damaging attack
 wDamageEffectiveness:: ; ccc1
@@ -999,16 +996,15 @@ wccec:: ; ccec
 	ds $1
 
 ; used by the effect functions to return the cause of an effect to fail
-; $01: was not affected by a status condition
-; $02: prints WasUnsuccessfulText
-wcced:: ; cced
+; in order print the appropriate text
+wEffectFailed:: ; cced
 	ds $1
 
 wccee:: ; ccee
 	ds $1
 
-; when this is non-0, DUELVARS_ARENA_CARD_LAST_TURN_DAMAGE and the
-; next duelvar are always set to 0 after an attack
+; flag to determine whether DUELVARS_ARENA_CARD_LAST_TURN_DAMAGE
+; gets zeroed or gets updated with wDealtDamage
 wccef:: ; ccef
 	ds $1
 
@@ -1017,7 +1013,7 @@ wccf0:: ; ccf0
 
 ; effect functions return a status condition constant here when it had no effect
 ; on the target, in order to print one of the ThereWasNoEffectFrom* texts
-wccf1:: ; ccf1
+wNoEffectFromStatus:: ; ccf1
 	ds $1
 
 ; when non-0, allows the player to skip some delays during a duel by pressing B.
@@ -1301,12 +1297,16 @@ wTextBoxLabel:: ; ce4c
 wCoinTossScreenTextID:: ; ce4e
 	ds $2
 
-; these hold either player or opponent turn
-; for temporary calculations
-wTurnHolder1:: ; ce50
+; set to PLAYER_TURN in the "Your Play Area" screen
+; set to OPPONENT_TURN in the  "Opp Play Area" screen
+; alternates when drawing the "In Play Area" screen
+wCheckMenuPlayAreaWhichDuelist:: ; ce50
 	ds $1
 
-wTurnHolder2:: ; ce51
+; apparently complements wCheckMenuPlayAreaWhichDuelist to be able to combine
+; the usual player or opponent layout with the opposite duelist information
+; appears not to be relevant in the "In Play Area" screen
+wCheckMenuPlayAreaWhichLayout:: ; ce51
 	ds $1
 
 ; holds the position of the cursor
@@ -1470,7 +1470,7 @@ wceb4:: ; ceb4
 wceb5:: ; ceb5
 	ds $1
 
-; used to store the tens digit and 
+; used to store the tens digit and
 ; ones digit of a value for printing
 ; the ones digit is added $20
 ; ceb6 = ones digit (+ $20)