lots more relabeling

27 files changed, 436 insertions, 390 deletions

diff --git a/src/battle_4.c b/src/battle_4.c
index ef8307da2..65ea765cf 100644
--- a/src/battle_4.c
+++ b/src/battle_4.c
@@ -154,7 +154,7 @@ u8 GetMoveTarget(u16 move, u8 targetbyte); //get target of move
 void sub_80153D0(u8 atk); //pressure perish song pp decrement
 u8 CastformDataTypeChange(u8 bank);
 void b_push_move_exec(u8* bs_ptr);
-u8 sav1_map_get_light_level(void);
+u8 Overworld_GetMapTypeOfSaveblockLocation(void);
 u8 CalculatePlayerPartyCount(void);
 u16 Sqrt(u32 num);
 u8 sub_809070C(u16 nationalNum, u32 TiD, u32 PiD); //task prepare poke dex display
@@ -17570,28 +17570,28 @@ static void atkE4_getsecretpowereffect(void)
 {
     switch (gBattleTerrain)
     {
-    case 0:
+    case BATTLE_TERRAIN_GRASS:
         gBattleCommunication[MOVE_EFFECT_BYTE] = 2;
         break;
-    case 1:
+    case BATTLE_TERRAIN_LONG_GRASS:
         gBattleCommunication[MOVE_EFFECT_BYTE] = 1;
         break;
-    case 2:
+    case BATTLE_TERRAIN_SAND:
         gBattleCommunication[MOVE_EFFECT_BYTE] = 27;
         break;
-    case 3:
+    case BATTLE_TERRAIN_UNDERWATER:
         gBattleCommunication[MOVE_EFFECT_BYTE] = 23;
         break;
-    case 4:
+    case BATTLE_TERRAIN_WATER:
         gBattleCommunication[MOVE_EFFECT_BYTE] = 22;
         break;
-    case 5:
+    case BATTLE_TERRAIN_POND:
         gBattleCommunication[MOVE_EFFECT_BYTE] = 24;
         break;
-    case 6:
+    case BATTLE_TERRAIN_MOUNTAIN:
         gBattleCommunication[MOVE_EFFECT_BYTE] = 7;
         break;
-    case 7:
+    case BATTLE_TERRAIN_CAVE:
         gBattleCommunication[MOVE_EFFECT_BYTE] = 8;
         break;
     default:
@@ -17818,7 +17818,7 @@ void atkEF_pokeball_catch_calculation(void)
                     ball_multiplier = 10;
                 break;
             case ITEM_DIVE_BALL:
-                if (sav1_map_get_light_level() == 5)
+                if (Overworld_GetMapTypeOfSaveblockLocation() == 5)
                     ball_multiplier = 35;
                 else
                     ball_multiplier = 10;
diff --git a/src/battle_setup.c b/src/battle_setup.c
index b3a7e2189..dba2a6ed4 100644
--- a/src/battle_setup.c
+++ b/src/battle_setup.c
@@ -642,11 +642,11 @@ s8 BattleSetup_GetTerrain(void)
     tileBehavior = MapGridGetMetatileBehaviorAt(x, y);
 
     if (MetatileBehavior_IsTallGrass(tileBehavior))
-        return 0;
+        return BATTLE_TERRAIN_GRASS;
     if (MetatileBehavior_IsLongGrass(tileBehavior))
-        return 1;
+        return BATTLE_TERRAIN_LONG_GRASS;
     if (MetatileBehavior_IsSandOrDeepSand(tileBehavior))
-        return 2;
+        return BATTLE_TERRAIN_SAND;
     switch (gMapHeader.mapType)
     {
     case MAP_TYPE_TOWN:
@@ -655,38 +655,38 @@ s8 BattleSetup_GetTerrain(void)
         break;
     case MAP_TYPE_UNDERGROUND:
         if (sub_80574C4(tileBehavior))
-            return 8;
+            return BATTLE_TERRAIN_BUILDING;
         if (MetatileBehavior_IsSurfableWaterOrUnderwater(tileBehavior))
-            return 5;
-        return 7;
+            return BATTLE_TERRAIN_POND;
+        return BATTLE_TERRAIN_CAVE;
     case MAP_TYPE_INDOOR:
     case MAP_TYPE_SECRET_BASE:
-        return 8;
+        return BATTLE_TERRAIN_BUILDING;
     case MAP_TYPE_UNDERWATER:
-        return 3;
+        return BATTLE_TERRAIN_UNDERWATER;
     case MAP_TYPE_6:
         if (MetatileBehavior_IsSurfableWaterOrUnderwater(tileBehavior))
-            return 4;
-        return 9;
+            return BATTLE_TERRAIN_WATER;
+        return BATTLE_TERRAIN_PLAIN;
     }
     if (sub_8057568(tileBehavior))
-        return 4;
+        return BATTLE_TERRAIN_WATER;
     if (MetatileBehavior_IsSurfableWaterOrUnderwater(tileBehavior))
-        return 5;
+        return BATTLE_TERRAIN_POND;
     if (sub_80574D8(tileBehavior))
-        return 6;
+        return BATTLE_TERRAIN_MOUNTAIN;
     if (TestPlayerAvatarFlags(PLAYER_AVATAR_FLAG_SURFING))
     {
         if (sub_8057450(tileBehavior))
-            return 5;
+            return BATTLE_TERRAIN_POND;
         if (MetatileBehavior_IsBridge(tileBehavior) == TRUE)
-            return 4;
+            return BATTLE_TERRAIN_WATER;
     }
-    if (gSaveBlock1.location.mapGroup == 0 && gSaveBlock1.location.mapNum == 28)
-        return 2;
+    if (gSaveBlock1.location.mapGroup == MAP_GROUP_ROUTE113 && gSaveBlock1.location.mapNum == MAP_ID_ROUTE113)
+        return BATTLE_TERRAIN_SAND;
     if (GetSav1Weather() == 8)
-        return 2;
-    return 9;
+        return BATTLE_TERRAIN_SAND;
+    return BATTLE_TERRAIN_PLAIN;
 }
 
 static s8 GetBattleTransitionTypeByMap(void)
@@ -696,7 +696,7 @@ static s8 GetBattleTransitionTypeByMap(void)
 
     PlayerGetDestCoords(&x, &y);
     tileBehavior = MapGridGetMetatileBehaviorAt(x, y);
-    if (sav1_get_flash_used_on_map())
+    if (Overworld_GetFlashLevel())
         return 2;
     if (!MetatileBehavior_IsSurfableWaterOrUnderwater(tileBehavior))
     {
diff --git a/src/bike.c b/src/bike.c
index eaaf17a71..cd0324bd5 100644
--- a/src/bike.c
+++ b/src/bike.c
@@ -944,7 +944,7 @@ void GetOnOffBike(u8 var)
     {
         SetPlayerAvatarTransitionFlags(var);
         sav1_set_battle_music_maybe(BGM_CYCLING);
-        ChangeMapMusic(BGM_CYCLING);
+        Overworld_ChangeMusicTo(BGM_CYCLING);
     }
 }
 
diff --git a/src/evolution_scene.c b/src/evolution_scene.c
index eeeb04f56..d0bd219cd 100644
--- a/src/evolution_scene.c
+++ b/src/evolution_scene.c
@@ -212,7 +212,7 @@ void EvolutionScene(struct Pokemon* mon, u16 speciesToEvolve, bool8 canStopEvo,
     gUnknown_030041B8 = 0;
 
     InitWindowFromConfig(&gUnknown_03004210, &gWindowConfig_81E6C58);
-    gBattleTerrain = 9;
+    gBattleTerrain = BATTLE_TERRAIN_PLAIN;
 
     sub_800D6D4();
     sub_800DAB8();
@@ -320,7 +320,7 @@ static void CB2_EvolutionSceneLoadGraphics(void)
     gUnknown_030041B8 = 0;
 
     InitWindowFromConfig(&gUnknown_03004210, &gWindowConfig_81E6C58);
-    gBattleTerrain = 9;
+    gBattleTerrain = BATTLE_TERRAIN_PLAIN;
 
     sub_800D6D4();
     sub_800DAB8();
diff --git a/src/field_control_avatar.c b/src/field_control_avatar.c
index a8f6b6b9b..80c04652b 100644
--- a/src/field_control_avatar.c
+++ b/src/field_control_avatar.c
@@ -698,7 +698,7 @@ static void sub_8068C30(struct MapHeader *unused, s8 b, struct MapPosition *posi
 
         warp1_set_2(warpEvent->unk7, warpEvent->mapNum, warpEvent->mapGroup);
         sub_80535C4(position->x, position->y);
-        mapHeader = get_mapheader_by_bank_and_number(warpEvent->unk7, warpEvent->mapNum);
+        mapHeader = Overworld_GetMapHeaderByGroupAndId(warpEvent->unk7, warpEvent->mapNum);
         if (mapHeader->events->warps[warpEvent->mapGroup].mapNum == 0x7F)
             saved_warp2_set(mapHeader->events->warps[b].mapGroup, gSaveBlock1.location.mapGroup, gSaveBlock1.location.mapNum, b);
     }
diff --git a/src/field_effect.c b/src/field_effect.c
index 168962ca1..79c00edff 100644
--- a/src/field_effect.c
+++ b/src/field_effect.c
@@ -2385,7 +2385,7 @@ void sub_8088890(struct Sprite *);
 bool8 FldEff_FieldMoveShowMon(void)
 {
     u8 taskId;
-    if (is_light_level_1_2_3_5_or_6(sav1_map_get_light_level()) == TRUE)
+    if (is_map_type_1_2_3_5_or_6(Overworld_GetMapTypeOfSaveblockLocation()) == TRUE)
     {
         taskId = CreateTask(sub_8088120, 0xff);
     } else
@@ -2881,7 +2881,7 @@ u8 FldEff_UseSurf(void)
     taskId = CreateTask(sub_8088954, 0xff);
     gTasks[taskId].data[15] = gFieldEffectArguments[0];
     sav1_reset_battle_music_maybe();
-    ChangeMapMusic(0x016d);
+    Overworld_ChangeMusicTo(0x016d);
     return FALSE;
 }
 
diff --git a/src/field_fadetransition.c b/src/field_fadetransition.c
index 89051e794..d1890013a 100644
--- a/src/field_fadetransition.c
+++ b/src/field_fadetransition.c
@@ -40,8 +40,8 @@ void palette_bg_fill_black(void)
 
 void pal_fill_for_map_transition(void)
 {
-    u8 map_light = get_map_light_from_warp0();
-    switch (fade_type_for_given_maplight_pair(map_light, sav1_map_get_light_level()))
+    u8 map_light = get_map_type_from_warp0();
+    switch (fade_type_for_given_maplight_pair(map_light, Overworld_GetMapTypeOfSaveblockLocation()))
     {
     case 0:
         fade_screen(0, 0);
@@ -61,7 +61,7 @@ void pal_fill_black(void)
 
 void fade_8080918(void)
 {
-    u8 light_level = sav1_map_get_light_level();
+    u8 light_level = Overworld_GetMapTypeOfSaveblockLocation();
     switch (sub_810CDB8(light_level, warp1_get_mapheader()->mapType))
     {
     case 0:
diff --git a/src/field_map_obj.c b/src/field_map_obj.c
index 73bd5508a..b8dce3dc2 100644
--- a/src/field_map_obj.c
+++ b/src/field_map_obj.c
@@ -3244,7 +3244,7 @@ struct MapObjectTemplate *GetFieldObjectTemplateByLocalIdAndMap(u8 localId, u8 m
         return FindFieldObjectTemplateInArrayByLocalId(localId, gSaveBlock1.mapObjectTemplates, gMapHeader.events->mapObjectCount);
     else
     {
-        struct MapHeader *mapHeader = get_mapheader_by_bank_and_number(mapGroup, mapNum);
+        struct MapHeader *mapHeader = Overworld_GetMapHeaderByGroupAndId(mapGroup, mapNum);
 
         return FindFieldObjectTemplateInArrayByLocalId(localId, mapHeader->events->mapObjects, mapHeader->events->mapObjectCount);
     }
diff --git a/src/field_screen_effect.c b/src/field_screen_effect.c
index 79913e1c5..c6a442f39 100644
--- a/src/field_screen_effect.c
+++ b/src/field_screen_effect.c
@@ -21,7 +21,7 @@ extern u16 gUnknown_03004DE0[][0x3C0];
 
 const static u16 gUnknown_0839ACDC[] = { 0xC8, 0x48, 0x38, 0x28, 0x18, 0x0 };
 
-const s32 gUnknown_0839ACE8 = 4;
+const s32 gMaxFlashLevel = 4;
 
 const static u32 gUnknown_0839ACEC[3] =
 {
@@ -137,11 +137,11 @@ static u8 sub_8081534(s32 a1, s32 a2, s32 a3, s32 a4, s32 a5, u8 a6)
 
 void sub_8081594(u8 a1)
 {
-    u8 index = sav1_get_flash_used_on_map();
+    u8 flashLevel = Overworld_GetFlashLevel();
     u8 value = 0;
     if (!a1)
         value = 1;
-    sub_8081534(120, 80, gUnknown_0839ACDC[index], gUnknown_0839ACDC[a1], value, 1);
+    sub_8081534(120, 80, gUnknown_0839ACDC[flashLevel], gUnknown_0839ACDC[a1], value, 1);
     sub_8081510();
     ScriptContext2_Enable();
 }
diff --git a/src/field_specials.c b/src/field_specials.c
index 454bd8d96..000992ffe 100644
--- a/src/field_specials.c
+++ b/src/field_specials.c
@@ -2005,7 +2005,7 @@ bool8 sub_810F828(void)
 
 void SetRoute119Weather(void)
 {
-    if (is_light_level_1_2_3_5_or_6(get_map_light_from_warp0()) != TRUE)
+    if (is_map_type_1_2_3_5_or_6(get_map_type_from_warp0()) != TRUE)
     {
         SetSav1Weather(0x14);
     }
@@ -2013,7 +2013,7 @@ void SetRoute119Weather(void)
 
 void SetRoute123Weather(void)
 {
-    if (is_light_level_1_2_3_5_or_6(get_map_light_from_warp0()) != TRUE)
+    if (is_map_type_1_2_3_5_or_6(get_map_type_from_warp0()) != TRUE)
     {
         SetSav1Weather(0x15);
     }
diff --git a/src/fieldmap.c b/src/fieldmap.c
index 0e0ec246c..af1d5f6b6 100644
--- a/src/fieldmap.c
+++ b/src/fieldmap.c
@@ -31,7 +31,7 @@ static const struct ConnectionFlags sDummyConnectionFlags = {0};
 
 struct MapHeader *mapconnection_get_mapheader(struct MapConnection *connection)
 {
-    return get_mapheader_by_bank_and_number(connection->mapGroup, connection->mapNum);
+    return Overworld_GetMapHeaderByGroupAndId(connection->mapGroup, connection->mapNum);
 }
 
 void not_trainer_hill_battle_pyramid(void)
diff --git a/src/fldeff_cut.c b/src/fldeff_cut.c
index 2691f1a75..edc1b578c 100644
--- a/src/fldeff_cut.c
+++ b/src/fldeff_cut.c
@@ -38,7 +38,7 @@ bool8 SetUpFieldMove_Cut(void)
 
     if(npc_before_player_of_type(0x52) == TRUE) // is in front of tree?
     {
-        gFieldCallback = sub_808AB90;
+        gFieldCallback = FieldCallback_Teleport;
         gUnknown_03005CE4 = sub_80A2634;
         return TRUE;
     }
@@ -57,7 +57,7 @@ bool8 SetUpFieldMove_Cut(void)
                     if(MetatileBehavior_IsPokeGrass(tileBehavior) == TRUE
                     || MetatileBehavior_IsAshGrass(tileBehavior) == TRUE)
                     {
-                        gFieldCallback = sub_808AB90;
+                        gFieldCallback = FieldCallback_Teleport;
                         gUnknown_03005CE4 = sub_80A25E8;
                         return TRUE;
                     }
diff --git a/src/fldeff_flash.c b/src/fldeff_flash.c
index a63cbbbf1..c965d3f64 100644
--- a/src/fldeff_flash.c
+++ b/src/fldeff_flash.c
@@ -51,7 +51,7 @@ bool8 SetUpFieldMove_Flash(void)
 {
     if (gMapHeader.cave == TRUE && !FlagGet(SYS_USE_FLASH))
     {
-        gFieldCallback = sub_808AB90;
+        gFieldCallback = FieldCallback_Teleport;
         gUnknown_03005CE4 = sub_810CBFC;
         return TRUE;
     }
@@ -123,8 +123,8 @@ void sub_810CC80(void)
 bool8 sub_810CD5C(void)
 {
     u8 i;
-    u8 v0 = get_map_light_from_warp0();
-    u8 v1 = sav1_map_get_light_level();
+    u8 v0 = get_map_type_from_warp0();
+    u8 v1 = Overworld_GetMapTypeOfSaveblockLocation();
 
     for (i = 0; gUnknown_083F7FC4[i].unk0; i++)
     {
diff --git a/src/fldeff_strength.c b/src/fldeff_strength.c
index c641945d6..a2572a6cf 100644
--- a/src/fldeff_strength.c
+++ b/src/fldeff_strength.c
@@ -25,7 +25,7 @@ bool8 SetUpFieldMove_Strength(void)
     if (ShouldDoBrailleStrengthEffect())
     {
         gScriptResult = gLastFieldPokeMenuOpened;
-        gFieldCallback = sub_808AB90;
+        gFieldCallback = FieldCallback_Teleport;
         gUnknown_03005CE4 = sub_811AA38;
     }
     else
@@ -33,7 +33,7 @@ bool8 SetUpFieldMove_Strength(void)
         if (npc_before_player_of_type(87) != TRUE)
             return 0;
         gScriptResult = gLastFieldPokeMenuOpened;
-        gFieldCallback = sub_808AB90;
+        gFieldCallback = FieldCallback_Teleport;
         gUnknown_03005CE4 = sub_811AA18;
     }
 
diff --git a/src/fldeff_sweetscent.c b/src/fldeff_sweetscent.c
index 661092ea0..2b36d2fe9 100644
--- a/src/fldeff_sweetscent.c
+++ b/src/fldeff_sweetscent.c
@@ -23,7 +23,7 @@ extern u8 SweetScentNothingHereScript[];
 
 bool8 SetUpFieldMove_SweetScent(void)
 {
-    gFieldCallback = sub_808AB90;
+    gFieldCallback = FieldCallback_Teleport;
     gUnknown_03005CE4 = sub_812BFD4;
     return TRUE;
 }
diff --git a/src/fldeff_teleport.c b/src/fldeff_teleport.c
index 10fdcce6e..3835d9eb6 100644
--- a/src/fldeff_teleport.c
+++ b/src/fldeff_teleport.c
@@ -13,9 +13,9 @@ extern void (*gUnknown_03005CE4)(void);
 
 bool8 SetUpFieldMove_Teleport(void)
 {
-    if (is_light_level_1_2_3_or_6(gMapHeader.mapType) == TRUE)
+    if (Overworld_MapTypeAllowsTeleportAndFly(gMapHeader.mapType) == TRUE)
     {
-        gFieldCallback = sub_808AB90;
+        gFieldCallback = FieldCallback_Teleport;
         gUnknown_03005CE4 = hm_teleport_run_dp02scr;
         return TRUE;
     }
@@ -25,7 +25,7 @@ bool8 SetUpFieldMove_Teleport(void)
 
 void hm_teleport_run_dp02scr(void)
 {
-    new_game();
+    Overworld_ResetStateAfterTeleport();
     FieldEffectStart(63);
     gFieldEffectArguments[0] = gLastFieldPokeMenuOpened;
 }
diff --git a/src/item_use.c b/src/item_use.c
index 1750c1584..c5fd990d2 100644
--- a/src/item_use.c
+++ b/src/item_use.c
@@ -185,7 +185,7 @@ void ItemUseOutOfBattle_Bike(u8 taskId)
     }
     else
     {
-        if (IsBikingAllowedByMap() == TRUE && IsBikingDisallowedByPlayer() == FALSE)
+        if (Overworld_IsBikeAllowedOnCurrentMap() == TRUE && IsBikingDisallowedByPlayer() == FALSE)
         {
             gUnknown_03005D00 = (void *)ItemUseOnFieldCB_Bike;
             SetUpItemUseOnFieldCallback(taskId);
diff --git a/src/main_menu.c b/src/main_menu.c
index 3b616065b..f4e7a3247 100644
--- a/src/main_menu.c
+++ b/src/main_menu.c
@@ -56,32 +56,14 @@ extern const union AffineAnimCmd *const gSpriteAffineAnimTable_81E79AC[];
 
 extern u8 unk_2000000[];
 
-//Task data
-enum {
-    TD_MENULAYOUT,
-    TD_SELECTEDMENUITEM,
-};
-
 //Menu layouts
-enum {
+enum
+{
     HAS_NO_SAVED_GAME,  //NEW GAME, OPTION
     HAS_SAVED_GAME,     //CONTINUE, NEW GAME, OPTION
     HAS_MYSTERY_GIFT,   //CONTINUE, NEW GAME, MYSTERY EVENTS, OPTION
 };
 
-//Task data
-enum {
-    TD_TRAINER_SPRITE_ID = 2,       //Trainer sprite being displayed during gender menu
-    TD_BGHOFS = 4,                  //Used to set REG_BG1HOFS and slide the platform around
-    TD_SUBTASK_DONE,                //Set to true if the spawned task has finished
-    TD_GENDER_SELECTION,
-    TD_COUNTER,
-    TD_BIRCH_SPRITE_ID,
-    TD_AZURILL_SPRITE_ID,
-    TD_BRENDAN_SPRITE_ID,
-    TD_MAY_SPRITE_ID
-};
-
 static void CB2_MainMenu(void);
 static void VBlankCB_MainMenu(void);
 static void CB2_InitMainMenuFromOptions(void);
@@ -180,6 +162,9 @@ static void CB2_InitMainMenuFromOptions(void)
     InitMainMenu(TRUE);
 }
 
+#define tMenuLayout    data[0]
+#define tMenuSelection data[1]
+
 u32 InitMainMenu(u8 a1)
 {
     u16 savedIme;
@@ -239,7 +224,7 @@ u32 InitMainMenu(u8 a1)
                 | DISPCNT_WIN0_ON;
 
     taskId = CreateTask(Task_MainMenuCheckSave, 0);
-    gTasks[taskId].data[TD_SELECTEDMENUITEM] = 0;
+    gTasks[taskId].tMenuSelection = 0;
 
     return 0;
 }
@@ -261,9 +246,9 @@ void Task_MainMenuCheckSave(u8 taskId)
     {
     case 1:
         if (IsMysteryGiftEnabled() == TRUE)
-            gTasks[taskId].data[TD_MENULAYOUT] = HAS_MYSTERY_GIFT;
+            gTasks[taskId].tMenuLayout = HAS_MYSTERY_GIFT;
         else
-            gTasks[taskId].data[TD_MENULAYOUT] = HAS_SAVED_GAME;
+            gTasks[taskId].tMenuLayout = HAS_SAVED_GAME;
 
         gTasks[taskId].func = Task_MainMenuCheckRtc;
         break;
@@ -272,7 +257,7 @@ void Task_MainMenuCheckSave(u8 taskId)
         MenuPrintMessage(gSaveFileDeletedMessage, 3, 15);
         REG_WIN0H = WIN_RANGE(17, 223);
         REG_WIN0V = WIN_RANGE(113, 159);
-        gTasks[taskId].data[TD_MENULAYOUT] = HAS_NO_SAVED_GAME;
+        gTasks[taskId].tMenuLayout = HAS_NO_SAVED_GAME;
         gTasks[taskId].func = Task_MainMenuWaitForSaveErrorAck;
         break;
     case 255:
@@ -280,17 +265,17 @@ void Task_MainMenuCheckSave(u8 taskId)
         MenuPrintMessage(gSaveFileCorruptMessage, 3, 15);
         REG_WIN0H = WIN_RANGE(17, 223);
         REG_WIN0V = WIN_RANGE(113, 159);
-        gTasks[taskId].data[TD_MENULAYOUT] = HAS_SAVED_GAME;
+        gTasks[taskId].tMenuLayout = HAS_SAVED_GAME;
         gTasks[taskId].func = Task_MainMenuWaitForSaveErrorAck;
 
         if (IsMysteryGiftEnabled() == TRUE)
-            gTasks[taskId].data[TD_MENULAYOUT] = HAS_MYSTERY_GIFT;
+            gTasks[taskId].tMenuLayout = HAS_MYSTERY_GIFT;
         else
-            gTasks[taskId].data[TD_MENULAYOUT] = HAS_SAVED_GAME;
+            gTasks[taskId].tMenuLayout = HAS_SAVED_GAME;
         break;
     case 0:
     default:
-        gTasks[taskId].data[TD_MENULAYOUT] = HAS_NO_SAVED_GAME;
+        gTasks[taskId].tMenuLayout = HAS_NO_SAVED_GAME;
         gTasks[taskId].func = Task_MainMenuCheckRtc;
         break;
     case 4:
@@ -298,7 +283,7 @@ void Task_MainMenuCheckSave(u8 taskId)
         MenuPrintMessage(gBoardNotInstalledMessage, 3, 15);
         REG_WIN0H = WIN_RANGE(17, 223);
         REG_WIN0V = WIN_RANGE(113, 159);
-        gTasks[taskId].data[TD_MENULAYOUT] = HAS_NO_SAVED_GAME;
+        gTasks[taskId].tMenuLayout = HAS_NO_SAVED_GAME;
         gTasks[taskId].func = Task_MainMenuWaitForSaveErrorAck;
         return;
     }
@@ -383,7 +368,7 @@ void Task_MainMenuDraw(u8 taskId)
             LoadPalette(&palette, 241, 2);
         }
 
-        switch (gTasks[taskId].data[TD_MENULAYOUT])
+        switch (gTasks[taskId].tMenuLayout)
         {
         case HAS_NO_SAVED_GAME:
         default:
@@ -420,7 +405,7 @@ void Task_MainMenuDraw(u8 taskId)
 
 void Task_MainMenuHighlight(u8 taskId)
 {
-    HighlightCurrentMenuItem(gTasks[taskId].data[TD_MENULAYOUT], gTasks[taskId].data[TD_SELECTEDMENUITEM]);
+    HighlightCurrentMenuItem(gTasks[taskId].tMenuLayout, gTasks[taskId].tMenuSelection);
     gTasks[taskId].func = Task_MainMenuProcessKeyInput;
 }
 
@@ -444,7 +429,7 @@ bool8 MainMenuProcessKeyInput(u8 taskId)
     {
         s32 menuItemCount;
 
-        switch (gTasks[taskId].data[TD_MENULAYOUT])
+        switch (gTasks[taskId].tMenuLayout)
         {
         case HAS_NO_SAVED_GAME:
         default:
@@ -460,17 +445,17 @@ bool8 MainMenuProcessKeyInput(u8 taskId)
 
         if (gMain.newKeys & DPAD_UP)
         {
-            if (gTasks[taskId].data[TD_SELECTEDMENUITEM] > 0)
+            if (gTasks[taskId].tMenuSelection > 0)
             {
-                gTasks[taskId].data[TD_SELECTEDMENUITEM]--;
+                gTasks[taskId].tMenuSelection--;
                 return TRUE;
             }
         }
         if (gMain.newKeys & DPAD_DOWN)
         {
-            if (gTasks[taskId].data[TD_SELECTEDMENUITEM] < menuItemCount - 1)
+            if (gTasks[taskId].tMenuSelection < menuItemCount - 1)
             {
-                gTasks[taskId].data[TD_SELECTEDMENUITEM]++;
+                gTasks[taskId].tMenuSelection++;
                 return TRUE;
             }
         }
@@ -499,11 +484,11 @@ void Task_MainMenuPressedA(u8 taskId)
     if (gPaletteFade.active)
         return;
 
-    switch (gTasks[taskId].data[TD_MENULAYOUT])
+    switch (gTasks[taskId].tMenuLayout)
     {
     case HAS_NO_SAVED_GAME:
     default:
-        switch (gTasks[taskId].data[TD_SELECTEDMENUITEM])
+        switch (gTasks[taskId].tMenuSelection)
         {
         case 0:
         default:
@@ -515,7 +500,7 @@ void Task_MainMenuPressedA(u8 taskId)
         }
         break;
     case HAS_SAVED_GAME:
-        switch (gTasks[taskId].data[TD_SELECTEDMENUITEM])
+        switch (gTasks[taskId].tMenuSelection)
         {
         case 0:
         default:
@@ -530,7 +515,7 @@ void Task_MainMenuPressedA(u8 taskId)
         }
         break;
     case HAS_MYSTERY_GIFT:
-        switch (gTasks[taskId].data[TD_SELECTEDMENUITEM])
+        switch (gTasks[taskId].tMenuSelection)
         {
         case 0:
         default:
@@ -584,6 +569,9 @@ void Task_MainMenuPressedB(u8 taskId)
     }
 }
 
+#undef tMenuLayout
+#undef tMenuSelection
+
 void HighlightCurrentMenuItem(u8 layout, u8 menuItem)
 {
     REG_WIN0H = WIN_RANGE(9, 231);
@@ -710,6 +698,16 @@ void PrintBadgeCount(void)
     MenuPrint_PixelCoords(buffer, 205, 40, 1);
 }
 
+#define tTrainerSpriteId data[2]
+#define tBGhofs          data[4]
+#define tSubtaskIsDone   data[5]
+#define tGenderSelection data[6]
+#define tFrameCounter    data[7]
+#define tBirchSpriteId   data[8]
+#define tAzurillSpriteId data[9]
+#define tBrendanSpriteId data[10]
+#define tMaySpriteId     data[11]
+
 static void Task_NewGameSpeech1(u8 taskId)
 {
     SetUpWindowConfig(&gWindowConfig_81E6C3C);
@@ -732,25 +730,25 @@ static void Task_NewGameSpeech1(u8 taskId)
     BeginNormalPaletteFade(-1, 0, 0x10, 0, 0);
     REG_BG1CNT = BGCNT_PRIORITY(3) | BGCNT_CHARBASE(0) | BGCNT_SCREENBASE(7) | BGCNT_16COLOR | BGCNT_TXT256x256;
     REG_DISPCNT = DISPCNT_MODE_0 | DISPCNT_BG0_ON | DISPCNT_BG1_ON | DISPCNT_OBJ_ON | DISPCNT_OBJ_1D_MAP;
-    gTasks[taskId].data[TD_BGHOFS] = 0;
+    gTasks[taskId].tBGhofs = 0;
     gTasks[taskId].func = Task_NewGameSpeech2;
-    gTasks[taskId].data[TD_TRAINER_SPRITE_ID] = 0xFF;
+    gTasks[taskId].tTrainerSpriteId = 0xFF;
     gTasks[taskId].data[3] = 0xFF;
-    gTasks[taskId].data[TD_COUNTER] = 216;  //Wait 3.6 seconds (216 frames) before starting speech
+    gTasks[taskId].tFrameCounter = 216;  //Wait 3.6 seconds (216 frames) before starting speech
 
     PlayBGM(BGM_DOORO_X4);
 }
 
 static void Task_NewGameSpeech2(u8 taskId)
 {
-    if (gTasks[taskId].data[TD_COUNTER] != 0)
+    if (gTasks[taskId].tFrameCounter != 0)
     {
-        gTasks[taskId].data[TD_COUNTER]--;
+        gTasks[taskId].tFrameCounter--;
     }
     else
     {
         //Initialize Birch sprite
-        u8 spriteId = gTasks[taskId].data[TD_BIRCH_SPRITE_ID];
+        u8 spriteId = gTasks[taskId].tBirchSpriteId;
 
         gSprites[spriteId].pos1.x = 136;
         gSprites[spriteId].pos1.y = 60;
@@ -758,19 +756,19 @@ static void Task_NewGameSpeech2(u8 taskId)
         gSprites[spriteId].oam.objMode = ST_OAM_OBJ_BLEND;
         StartSpriteFadeIn(taskId, 10);
         StartBackgroundFadeIn(taskId, 20);
-        gTasks[taskId].data[TD_COUNTER] = 80;
+        gTasks[taskId].tFrameCounter = 80;
         gTasks[taskId].func = Task_NewGameSpeech3;
     }
 }
 
 static void Task_NewGameSpeech3(u8 taskId)
 {
-    if (gTasks[taskId].data[TD_SUBTASK_DONE] != FALSE)
+    if (gTasks[taskId].tSubtaskIsDone)
     {
-        gSprites[gTasks[taskId].data[TD_BIRCH_SPRITE_ID]].oam.objMode = ST_OAM_OBJ_NORMAL;
-        if (gTasks[taskId].data[TD_COUNTER])
+        gSprites[gTasks[taskId].tBirchSpriteId].oam.objMode = ST_OAM_OBJ_NORMAL;
+        if (gTasks[taskId].tFrameCounter)
         {
-            gTasks[taskId].data[TD_COUNTER]--;
+            gTasks[taskId].tFrameCounter--;
         }
         else
         {
@@ -801,7 +799,7 @@ static void Task_NewGameSpeech5(u8 taskId)
 
 static void Task_NewGameSpeech6(u8 taskId)
 {
-    u8 spriteId = gTasks[taskId].data[TD_AZURILL_SPRITE_ID];
+    u8 spriteId = gTasks[taskId].tAzurillSpriteId;
 
     gSprites[spriteId].pos1.x = 104;
     gSprites[spriteId].pos1.y = 72;
@@ -809,7 +807,7 @@ static void Task_NewGameSpeech6(u8 taskId)
     gSprites[spriteId].data0 = 0;
     CreatePokeballSprite(spriteId, gSprites[spriteId].oam.paletteNum, 0x70, 0x3A, 0, 0, 0x20, 0x0000FFFF);
     gTasks[taskId].func = Task_NewGameSpeech7;
-    gTasks[taskId].data[TD_COUNTER] = 0;
+    gTasks[taskId].tFrameCounter = 0;
 }
 
 static void Task_NewGameSpeech7(u8 taskId)
@@ -817,18 +815,18 @@ static void Task_NewGameSpeech7(u8 taskId)
     if (IsCryFinished())
     {
         //Go on to next sentence after frame 95
-        if (gTasks[taskId].data[TD_COUNTER] > 95)
+        if (gTasks[taskId].tFrameCounter > 95)
         {
             MenuSetText(gSystemText_NewPara);
             gTasks[taskId].func = Task_NewGameSpeech8;
         }
     }
 
-    if (gTasks[taskId].data[TD_COUNTER] < 16384)
+    if (gTasks[taskId].tFrameCounter < 16384)
     {
-        gTasks[taskId].data[TD_COUNTER]++;
+        gTasks[taskId].tFrameCounter++;
         //Play Azurill cry at frame 32
-        if (gTasks[taskId].data[TD_COUNTER] == 32)
+        if (gTasks[taskId].tFrameCounter == 32)
             PlayCry1(SPECIES_AZURILL, 0);
     }
 }
@@ -859,11 +857,11 @@ static void Task_NewGameSpeech10(u8 taskId)
 {
     if (BirchSpeechUpdateWindowText())
     {
-        gSprites[gTasks[taskId].data[TD_BIRCH_SPRITE_ID]].oam.objMode = ST_OAM_OBJ_BLEND;
-        gSprites[gTasks[taskId].data[TD_AZURILL_SPRITE_ID]].oam.objMode = ST_OAM_OBJ_BLEND;
+        gSprites[gTasks[taskId].tBirchSpriteId].oam.objMode = ST_OAM_OBJ_BLEND;
+        gSprites[gTasks[taskId].tAzurillSpriteId].oam.objMode = ST_OAM_OBJ_BLEND;
         StartSpriteFadeOut(taskId, 2);
         StartBackgroundFadeOut(taskId, 1);
-        gTasks[taskId].data[TD_COUNTER] = 64;
+        gTasks[taskId].tFrameCounter = 64;
         gTasks[taskId].func = Task_NewGameSpeech11;
     }
 }
@@ -871,41 +869,41 @@ static void Task_NewGameSpeech10(u8 taskId)
 //Slide platform away to the right
 static void Task_NewGameSpeech11(u8 taskId)
 {
-    if (gTasks[taskId].data[TD_BGHOFS] != -60)
+    if (gTasks[taskId].tBGhofs != -60)
     {
-        gTasks[taskId].data[TD_BGHOFS] -= 2;
-        REG_BG1HOFS = gTasks[taskId].data[TD_BGHOFS];
+        gTasks[taskId].tBGhofs -= 2;
+        REG_BG1HOFS = gTasks[taskId].tBGhofs;
     }
     else
     {
-        gTasks[taskId].data[TD_BGHOFS] = -60;
+        gTasks[taskId].tBGhofs = -60;
         gTasks[taskId].func = Task_NewGameSpeech12;
     }
 }
 
 static void Task_NewGameSpeech12(u8 taskId)
 {
-    if (gTasks[taskId].data[TD_SUBTASK_DONE])
+    if (gTasks[taskId].tSubtaskIsDone)
     {
         //Hide Birch and Azurill
-        gSprites[gTasks[taskId].data[TD_BIRCH_SPRITE_ID]].invisible = TRUE;
-        gSprites[gTasks[taskId].data[TD_AZURILL_SPRITE_ID]].invisible = TRUE;
+        gSprites[gTasks[taskId].tBirchSpriteId].invisible = TRUE;
+        gSprites[gTasks[taskId].tAzurillSpriteId].invisible = TRUE;
 
-        if (gTasks[taskId].data[TD_COUNTER])
+        if (gTasks[taskId].tFrameCounter)
         {
-            gTasks[taskId].data[TD_COUNTER]--;
+            gTasks[taskId].tFrameCounter--;
         }
         else
         {
             //Initialize Brendan sprite
-            u8 spriteId = gTasks[taskId].data[TD_BRENDAN_SPRITE_ID];
+            u8 spriteId = gTasks[taskId].tBrendanSpriteId;
 
             gSprites[spriteId].pos1.x = 180;
             gSprites[spriteId].pos1.y = 60;
             gSprites[spriteId].invisible = FALSE;
             gSprites[spriteId].oam.objMode = ST_OAM_OBJ_BLEND;
-            gTasks[taskId].data[TD_TRAINER_SPRITE_ID] = spriteId;
-            gTasks[taskId].data[TD_GENDER_SELECTION] = 0;
+            gTasks[taskId].tTrainerSpriteId = spriteId;
+            gTasks[taskId].tGenderSelection = 0;
             StartSpriteFadeIn(taskId, 2);
             StartBackgroundFadeIn(taskId, 1);
             gTasks[taskId].func = Task_NewGameSpeech13;
@@ -915,9 +913,9 @@ static void Task_NewGameSpeech12(u8 taskId)
 
 static void Task_NewGameSpeech13(u8 taskId)
 {
-    if (gTasks[taskId].data[TD_SUBTASK_DONE])
+    if (gTasks[taskId].tSubtaskIsDone)
     {
-        gSprites[gTasks[taskId].data[TD_TRAINER_SPRITE_ID]].oam.objMode = ST_OAM_OBJ_NORMAL;
+        gSprites[gTasks[taskId].tTrainerSpriteId].oam.objMode = ST_OAM_OBJ_NORMAL;
         gTasks[taskId].func = Task_NewGameSpeech14;
     }
 }
@@ -964,11 +962,11 @@ static void Task_NewGameSpeech16(u8 taskId)
 
     cursorPos = GetMenuCursorPos();
 
-    if (cursorPos != gTasks[taskId].data[TD_GENDER_SELECTION])
+    if (cursorPos != gTasks[taskId].tGenderSelection)
     {
         //Menu selection changed. Slide Brendan or May out and slide the other in
-        gTasks[taskId].data[TD_GENDER_SELECTION] = cursorPos;
-        gSprites[gTasks[taskId].data[TD_TRAINER_SPRITE_ID]].oam.objMode = ST_OAM_OBJ_BLEND;
+        gTasks[taskId].tGenderSelection = cursorPos;
+        gSprites[gTasks[taskId].tTrainerSpriteId].oam.objMode = ST_OAM_OBJ_BLEND;
         StartSpriteFadeOut(taskId, 0);
         gTasks[taskId].func = Task_NewGameSpeech17;
     }
@@ -977,9 +975,9 @@ static void Task_NewGameSpeech16(u8 taskId)
 //Slide old trainer sprite off right of screen
 static void Task_NewGameSpeech17(u8 taskId)
 {
-    u8 spriteId = gTasks[taskId].data[TD_TRAINER_SPRITE_ID];
+    u8 spriteId = gTasks[taskId].tTrainerSpriteId;
 
-    if (gTasks[taskId].data[TD_SUBTASK_DONE] == FALSE)
+    if (gTasks[taskId].tSubtaskIsDone == FALSE)
     {
         gSprites[spriteId].pos1.x += 4;     //Move sprite right
     }
@@ -988,14 +986,14 @@ static void Task_NewGameSpeech17(u8 taskId)
         gSprites[spriteId].invisible = TRUE;
 
         //Set up new trainer sprite
-        if (gTasks[taskId].data[TD_GENDER_SELECTION])
-            spriteId = gTasks[taskId].data[TD_MAY_SPRITE_ID];
+        if (gTasks[taskId].tGenderSelection)
+            spriteId = gTasks[taskId].tMaySpriteId;
         else
-            spriteId = gTasks[taskId].data[TD_BRENDAN_SPRITE_ID];
+            spriteId = gTasks[taskId].tBrendanSpriteId;
         gSprites[spriteId].pos1.x = 240;
         gSprites[spriteId].pos1.y = 60;
         gSprites[spriteId].invisible = FALSE;
-        gTasks[taskId].data[TD_TRAINER_SPRITE_ID] = spriteId;
+        gTasks[taskId].tTrainerSpriteId = spriteId;
         gSprites[spriteId].oam.objMode = ST_OAM_OBJ_BLEND;
         StartSpriteFadeIn(taskId, 0);
         gTasks[taskId].func = Task_NewGameSpeech18;
@@ -1005,7 +1003,7 @@ static void Task_NewGameSpeech17(u8 taskId)
 //Slide new trainer sprite from right of screen
 static void Task_NewGameSpeech18(u8 taskId)
 {
-    u8 spriteId = gTasks[taskId].data[TD_TRAINER_SPRITE_ID];
+    u8 spriteId = gTasks[taskId].tTrainerSpriteId;
 
     if (gSprites[spriteId].pos1.x > 180)
     {
@@ -1014,7 +1012,7 @@ static void Task_NewGameSpeech18(u8 taskId)
     else
     {
         gSprites[spriteId].pos1.x = 180;
-        if (gTasks[taskId].data[TD_SUBTASK_DONE])
+        if (gTasks[taskId].tSubtaskIsDone)
         {
             gSprites[spriteId].oam.objMode = ST_OAM_OBJ_NORMAL;
             gTasks[taskId].func = Task_NewGameSpeech16; //Go back to gender menu
@@ -1106,7 +1104,7 @@ static void Task_NewGameSpeech25(u8 taskId)
     case 0:     //YES
         PlaySE(SE_SELECT);
         MenuZeroFillWindowRect(2, 1, 8, 7);
-        gSprites[gTasks[taskId].data[TD_TRAINER_SPRITE_ID]].oam.objMode = ST_OAM_OBJ_BLEND;
+        gSprites[gTasks[taskId].tTrainerSpriteId].oam.objMode = ST_OAM_OBJ_BLEND;
         StartSpriteFadeOut(taskId, 2);
         StartBackgroundFadeOut(taskId, 1);
         gTasks[taskId].func = Task_NewGameSpeech26;     //Continue
@@ -1122,10 +1120,10 @@ static void Task_NewGameSpeech25(u8 taskId)
 
 static void Task_NewGameSpeech26(u8 taskId)
 {
-    if (gTasks[taskId].data[TD_BGHOFS])
+    if (gTasks[taskId].tBGhofs)
     {
-        gTasks[taskId].data[TD_BGHOFS] += 2;
-        REG_BG1HOFS = gTasks[taskId].data[TD_BGHOFS];
+        gTasks[taskId].tBGhofs += 2;
+        REG_BG1HOFS = gTasks[taskId].tBGhofs;
     }
     else
     {
@@ -1135,23 +1133,23 @@ static void Task_NewGameSpeech26(u8 taskId)
 
 static void Task_NewGameSpeech27(u8 taskId)
 {
-    if (gTasks[taskId].data[TD_SUBTASK_DONE])
+    if (gTasks[taskId].tSubtaskIsDone)
     {
         s16 spriteId;
 
         //Hide Brendan and May sprites
-        spriteId = gTasks[taskId].data[TD_BRENDAN_SPRITE_ID];
+        spriteId = gTasks[taskId].tBrendanSpriteId;
         gSprites[spriteId].invisible = TRUE;
-        spriteId = gTasks[taskId].data[TD_MAY_SPRITE_ID];
+        spriteId = gTasks[taskId].tMaySpriteId;
         gSprites[spriteId].invisible = TRUE;
 
         //Fade in Birch and Azurill
-        spriteId = (u8)gTasks[taskId].data[TD_BIRCH_SPRITE_ID];
+        spriteId = (u8)gTasks[taskId].tBirchSpriteId;
         gSprites[spriteId].pos1.x = 136;
         gSprites[spriteId].pos1.y = 64;
         gSprites[spriteId].invisible = FALSE;
         gSprites[spriteId].oam.objMode = ST_OAM_OBJ_BLEND;
-        spriteId = (u8)gTasks[taskId].data[TD_AZURILL_SPRITE_ID];
+        spriteId = (u8)gTasks[taskId].tAzurillSpriteId;
         gSprites[spriteId].pos1.x = 104;
         gSprites[spriteId].pos1.y = 72;
         gSprites[spriteId].invisible = FALSE;
@@ -1170,27 +1168,27 @@ static void Task_NewGameSpeech27(u8 taskId)
 
 static void Task_NewGameSpeech28(u8 taskId)
 {
-    if (gTasks[taskId].data[TD_SUBTASK_DONE])
+    if (gTasks[taskId].tSubtaskIsDone)
     {
         s16 spriteId;
 
-        spriteId = gTasks[taskId].data[TD_BIRCH_SPRITE_ID];
+        spriteId = gTasks[taskId].tBirchSpriteId;
         gSprites[spriteId].oam.objMode = ST_OAM_OBJ_NORMAL;
 
-        spriteId = gTasks[taskId].data[TD_AZURILL_SPRITE_ID];
+        spriteId = gTasks[taskId].tAzurillSpriteId;
         gSprites[spriteId].oam.objMode = ST_OAM_OBJ_NORMAL;
 
         if (BirchSpeechUpdateWindowText())
         {
             //Fade out Birch and Azurill
-            spriteId = gTasks[taskId].data[TD_BIRCH_SPRITE_ID];
+            spriteId = gTasks[taskId].tBirchSpriteId;
             gSprites[spriteId].oam.objMode = ST_OAM_OBJ_BLEND;
-            spriteId = gTasks[taskId].data[TD_AZURILL_SPRITE_ID];
+            spriteId = gTasks[taskId].tAzurillSpriteId;
             gSprites[spriteId].oam.objMode = ST_OAM_OBJ_BLEND;
 
             StartSpriteFadeOut(taskId, 2);
             StartBackgroundFadeOut(taskId, 1);
-            gTasks[taskId].data[TD_COUNTER] = 64;
+            gTasks[taskId].tFrameCounter = 64;
             gTasks[taskId].func = Task_NewGameSpeech29;
         }
     }
@@ -1198,19 +1196,19 @@ static void Task_NewGameSpeech28(u8 taskId)
 
 static void Task_NewGameSpeech29(u8 taskId)
 {
-    if (gTasks[taskId].data[TD_SUBTASK_DONE])
+    if (gTasks[taskId].tSubtaskIsDone)
     {
         s16 spriteId;
 
         //Hide Birch and Azurill
-        spriteId = gTasks[taskId].data[TD_BIRCH_SPRITE_ID];
+        spriteId = gTasks[taskId].tBirchSpriteId;
         gSprites[spriteId].invisible = TRUE;
-        spriteId = gTasks[taskId].data[TD_AZURILL_SPRITE_ID];
+        spriteId = gTasks[taskId].tAzurillSpriteId;
         gSprites[spriteId].invisible = TRUE;
 
-        if (gTasks[taskId].data[TD_COUNTER])
+        if (gTasks[taskId].tFrameCounter)
         {
-            gTasks[taskId].data[TD_COUNTER]--;
+            gTasks[taskId].tFrameCounter--;
         }
         else
         {
@@ -1218,14 +1216,14 @@ static void Task_NewGameSpeech29(u8 taskId)
 
             //Fade in trainer and background
             if (gSaveBlock2.playerGender)
-                spriteId = (u8)gTasks[taskId].data[TD_MAY_SPRITE_ID];
+                spriteId = (u8)gTasks[taskId].tMaySpriteId;
             else
-                spriteId = (u8)gTasks[taskId].data[TD_BRENDAN_SPRITE_ID];
+                spriteId = (u8)gTasks[taskId].tBrendanSpriteId;
             gSprites[spriteId].pos1.x = 120;
             gSprites[spriteId].pos1.y = 60;
             gSprites[spriteId].invisible = FALSE;
             gSprites[spriteId].oam.objMode = ST_OAM_OBJ_BLEND;
-            gTasks[taskId].data[TD_TRAINER_SPRITE_ID] = spriteId;
+            gTasks[taskId].tTrainerSpriteId = spriteId;
 
             StartSpriteFadeIn(taskId, 2);
             StartBackgroundFadeIn(taskId, 1);
@@ -1238,18 +1236,18 @@ static void Task_NewGameSpeech29(u8 taskId)
 
 static void Task_NewGameSpeech30(u8 taskId)
 {
-    if (gTasks[taskId].data[TD_SUBTASK_DONE])
+    if (gTasks[taskId].tSubtaskIsDone)
     {
         s16 spriteId;
 
-        spriteId = gTasks[taskId].data[TD_TRAINER_SPRITE_ID];
+        spriteId = gTasks[taskId].tTrainerSpriteId;
         gSprites[spriteId].oam.objMode = ST_OAM_OBJ_NORMAL;
 
         if (BirchSpeechUpdateWindowText())
         {
             u8 spriteId;
 
-            spriteId = gTasks[taskId].data[TD_TRAINER_SPRITE_ID];
+            spriteId = gTasks[taskId].tTrainerSpriteId;
             gSprites[spriteId].oam.affineMode = 1;
             gSprites[spriteId].affineAnims = gSpriteAffineAnimTable_81E79AC;
             InitSpriteAffineAnim(&gSprites[spriteId]);
@@ -1264,7 +1262,7 @@ static void Task_NewGameSpeech30(u8 taskId)
 
 static void Task_NewGameSpeech31(u8 taskId)
 {
-    u8 spriteId = gTasks[taskId].data[TD_TRAINER_SPRITE_ID];
+    u8 spriteId = gTasks[taskId].tTrainerSpriteId;
 
     if (gSprites[spriteId].affineAnimEnded)
         gTasks[taskId].func = Task_NewGameSpeech32;
@@ -1274,7 +1272,7 @@ static void Task_NewGameSpeech32(u8 taskId)
 {
     if (!gPaletteFade.active)
     {
-        u8 spriteId = gTasks[taskId].data[TD_TRAINER_SPRITE_ID];
+        u8 spriteId = gTasks[taskId].tTrainerSpriteId;
         gSprites[spriteId].callback = nullsub_34;
         REG_DISPCNT = DISPCNT_MODE_0 | DISPCNT_OBJ_1D_MAP | DISPCNT_OBJ_ON;
         BeginNormalPaletteFade(0xFFFF0000, 0, 0, 0x10, 0xFFFF);
@@ -1328,7 +1326,7 @@ void CB_ContinueNewGameSpeechPart2()
 
     taskId = CreateTask(Task_NewGameSpeech23, 0);
 
-    gTasks[taskId].data[TD_BGHOFS] = -60;
+    gTasks[taskId].tBGhofs = -60;
 
     remove_some_task();
     ResetSpriteData();
@@ -1340,20 +1338,20 @@ void CB_ContinueNewGameSpeechPart2()
 
     if (gSaveBlock2.playerGender != MALE)
     {
-        gTasks[taskId].data[TD_GENDER_SELECTION] = FEMALE;
-        spriteId = gTasks[taskId].data[TD_MAY_SPRITE_ID];
+        gTasks[taskId].tGenderSelection = FEMALE;
+        spriteId = gTasks[taskId].tMaySpriteId;
     }
     else
     {
-        gTasks[taskId].data[TD_GENDER_SELECTION] = MALE;
-        spriteId = gTasks[taskId].data[TD_BRENDAN_SPRITE_ID];
+        gTasks[taskId].tGenderSelection = MALE;
+        spriteId = gTasks[taskId].tBrendanSpriteId;
     }
 
     gSprites[spriteId].pos1.x = 180;
     gSprites[spriteId].pos1.y = 60;
     gSprites[spriteId].invisible = FALSE;
 
-    gTasks[taskId].data[TD_TRAINER_SPRITE_ID] = spriteId;
+    gTasks[taskId].tTrainerSpriteId = spriteId;
 
     REG_BG1HOFS = -60;
 
@@ -1412,56 +1410,67 @@ void AddBirchSpeechObjects(u8 taskId)
     gSprites[spriteId].callback = nullsub_34;
     gSprites[spriteId].oam.priority = 0;
     gSprites[spriteId].invisible = 1;
-    gTasks[taskId].data[TD_BIRCH_SPRITE_ID] = spriteId;
+    gTasks[taskId].tBirchSpriteId = spriteId;
 
     spriteId = CreateAzurillSprite(0x68, 0x48);
     gSprites[spriteId].callback = nullsub_34;
     gSprites[spriteId].oam.priority = 0;
     gSprites[spriteId].invisible = 1;
-    gTasks[taskId].data[TD_AZURILL_SPRITE_ID] = spriteId;
+    gTasks[taskId].tAzurillSpriteId = spriteId;
 
     //Create Brendan sprite
     spriteId = CreateTrainerSprite(0, 120, 60, 0, unk_2000000);
     gSprites[spriteId].callback = nullsub_34;
     gSprites[spriteId].invisible = 1;
     gSprites[spriteId].oam.priority = 0;
-    gTasks[taskId].data[TD_BRENDAN_SPRITE_ID] = spriteId;
+    gTasks[taskId].tBrendanSpriteId = spriteId;
 
     //Create May sprite
     spriteId = CreateTrainerSprite(1, 120, 60, 0, unk_2000000 + 0x800);
     gSprites[spriteId].callback = nullsub_34;
     gSprites[spriteId].invisible = 1;
     gSprites[spriteId].oam.priority = 0;
-    gTasks[taskId].data[TD_MAY_SPRITE_ID] = spriteId;
+    gTasks[taskId].tMaySpriteId = spriteId;
 }
 
-enum {
-    TD_PARENT_TASK_ID,
-    TD_EVA,             //EVA coefficient of REG_BLDALPHA
-    TD_EVB,             //EVB coefficient of REG_BLDALPHA
-    TD_INTERVAL,
-    TD_FRAMECOUNTER
-};
+#undef tTrainerSpriteId
+#undef tBGhofs
+//#undef tSubtaskIsDone
+#undef tGenderSelection
+#undef tFrameCounter
+#undef tBirchSpriteId
+#undef tAzurillSpriteId
+#undef tBrendanSpriteId
+#undef tMaySpriteId
+
+
+// Sprite Fade task
+
+#define tMainTaskId     data[0]
+#define tBlendEVA       data[1]
+#define tBlendEVB       data[2]
+#define tUpdateInterval data[3]
+#define tFrameCounter   data[4]
 
 static void Task_SpriteFadeOut(u8 taskId)
 {
-    if (gTasks[taskId].data[TD_EVA] == 0)
+    if (gTasks[taskId].tBlendEVA == 0)
     {
-        gTasks[gTasks[taskId].data[TD_PARENT_TASK_ID]].data[TD_SUBTASK_DONE] = TRUE;
+        gTasks[gTasks[taskId].tMainTaskId].tSubtaskIsDone = TRUE;
         DestroyTask(taskId);
     }
     else
     {
-        if (gTasks[taskId].data[TD_FRAMECOUNTER])
+        if (gTasks[taskId].tFrameCounter)
         {
-            gTasks[taskId].data[TD_FRAMECOUNTER]--;
+            gTasks[taskId].tFrameCounter--;
         }
         else
         {
-            gTasks[taskId].data[TD_FRAMECOUNTER] = gTasks[taskId].data[TD_INTERVAL];
-            gTasks[taskId].data[TD_EVA]--;
-            gTasks[taskId].data[TD_EVB]++;
-            REG_BLDALPHA = gTasks[taskId].data[TD_EVA] + (gTasks[taskId].data[TD_EVB] * 256);
+            gTasks[taskId].tFrameCounter = gTasks[taskId].tUpdateInterval;
+            gTasks[taskId].tBlendEVA--;
+            gTasks[taskId].tBlendEVB++;
+            REG_BLDALPHA = gTasks[taskId].tBlendEVA + (gTasks[taskId].tBlendEVB * 256);
         }
     }
 }
@@ -1474,33 +1483,33 @@ static void StartSpriteFadeOut(u8 taskId, u8 interval)
     REG_BLDCNT = 592;
     REG_BLDALPHA = 16;
     REG_BLDY = 0;
-    gTasks[taskId].data[TD_SUBTASK_DONE] = FALSE;
+    gTasks[taskId].tSubtaskIsDone = FALSE;
     newTaskId = CreateTask(Task_SpriteFadeOut, 0);
 
-    gTasks[newTaskId].data[TD_PARENT_TASK_ID] = taskId;
-    gTasks[newTaskId].data[TD_EVA] = 16;
-    gTasks[newTaskId].data[TD_EVB] = 0;
-    gTasks[newTaskId].data[TD_INTERVAL] = interval;
-    gTasks[newTaskId].data[TD_FRAMECOUNTER] = interval;
+    gTasks[newTaskId].tMainTaskId = taskId;
+    gTasks[newTaskId].tBlendEVA = 16;
+    gTasks[newTaskId].tBlendEVB = 0;
+    gTasks[newTaskId].tUpdateInterval = interval;
+    gTasks[newTaskId].tFrameCounter = interval;
 }
 
 static void Task_SpriteFadeIn(u8 taskId)
 {
-    if (gTasks[taskId].data[TD_EVA] == 16)
+    if (gTasks[taskId].tBlendEVA == 16)
     {
-        gTasks[gTasks[taskId].data[TD_PARENT_TASK_ID]].data[TD_SUBTASK_DONE] = TRUE;
+        gTasks[gTasks[taskId].tMainTaskId].tSubtaskIsDone = TRUE;
         DestroyTask(taskId);
     }
-    else if (gTasks[taskId].data[TD_FRAMECOUNTER])
+    else if (gTasks[taskId].tFrameCounter)
     {
-        gTasks[taskId].data[TD_FRAMECOUNTER]--;
+        gTasks[taskId].tFrameCounter--;
     }
     else
     {
-        gTasks[taskId].data[TD_FRAMECOUNTER] = gTasks[taskId].data[TD_INTERVAL];
-        gTasks[taskId].data[TD_EVA]++;
-        gTasks[taskId].data[TD_EVB]--;
-        REG_BLDALPHA = gTasks[taskId].data[TD_EVA] + (gTasks[taskId].data[TD_EVB] * 256);
+        gTasks[taskId].tFrameCounter = gTasks[taskId].tUpdateInterval;
+        gTasks[taskId].tBlendEVA++;
+        gTasks[taskId].tBlendEVB--;
+        REG_BLDALPHA = gTasks[taskId].tBlendEVA + (gTasks[taskId].tBlendEVB * 256);
     }
 }
 
@@ -1512,36 +1521,49 @@ static void StartSpriteFadeIn(u8 taskId, u8 interval)
     REG_BLDCNT = 592;
     REG_BLDALPHA = 4096;
     REG_BLDY = 0;
-    gTasks[taskId].data[TD_SUBTASK_DONE] = FALSE;
+    gTasks[taskId].tSubtaskIsDone = FALSE;
     newTaskId = CreateTask(Task_SpriteFadeIn, 0);
 
-    gTasks[newTaskId].data[TD_PARENT_TASK_ID] = taskId;
-    gTasks[newTaskId].data[TD_EVA] = 0;
-    gTasks[newTaskId].data[TD_EVB] = 16;
-    gTasks[newTaskId].data[TD_INTERVAL] = interval;
-    gTasks[newTaskId].data[TD_FRAMECOUNTER] = interval;
+    gTasks[newTaskId].tMainTaskId = taskId;
+    gTasks[newTaskId].tBlendEVA = 0;
+    gTasks[newTaskId].tBlendEVB = 16;
+    gTasks[newTaskId].tUpdateInterval = interval;
+    gTasks[newTaskId].tFrameCounter = interval;
 }
 
-enum {
-    TD_FADELEVEL = 1,
-    TD_DELAY,
-};
+#undef tMainTaskId
+#undef tBlendEVA
+#undef tBlendEVB
+#undef tUpdateInterval
+#undef tFrameCounter
+
+
+// Background fade task
+
+#define tMainTaskId     data[0]
+#define tFadeLevel      data[1]
+#define tDelay          data[2]
+#define tUpdateInterval data[3]
+#define tFrameCounter   data[4]
 
 static void HandleFloorShadowFadeOut(u8 taskId)
 {
-    if (gTasks[taskId].data[TD_DELAY])
-        gTasks[taskId].data[TD_DELAY]--;
+    if (gTasks[taskId].tDelay)
+        gTasks[taskId].tDelay--;
     else
     {
-        if (gTasks[taskId].data[TD_FADELEVEL] == 8)
+        if (gTasks[taskId].tFadeLevel == 8)
             DestroyTask(taskId);
-        else if (gTasks[taskId].data[TD_FRAMECOUNTER])
-            gTasks[taskId].data[TD_FRAMECOUNTER]--;
         else
         {
-            gTasks[taskId].data[TD_FRAMECOUNTER] = gTasks[taskId].data[TD_INTERVAL];
-            gTasks[taskId].data[TD_FADELEVEL]++;
-            LoadPalette(&gUnknown_081E795C[gTasks[taskId].data[TD_FADELEVEL]], 1, 0x10);
+            if (gTasks[taskId].tFrameCounter)
+                gTasks[taskId].tFrameCounter--;
+            else
+            {
+                gTasks[taskId].tFrameCounter = gTasks[taskId].tUpdateInterval;
+                gTasks[taskId].tFadeLevel++;
+                LoadPalette(&gUnknown_081E795C[gTasks[taskId].tFadeLevel], 1, 0x10);
+            }
         }
     }
 }
@@ -1550,30 +1572,30 @@ static void HandleFloorShadowFadeOut(u8 taskId)
 static void StartBackgroundFadeOut(u8 taskId, u8 interval)
 {
     u8 newTaskId = CreateTask(HandleFloorShadowFadeOut, 0);
-    gTasks[newTaskId].data[TD_PARENT_TASK_ID] = taskId;
-    gTasks[newTaskId].data[TD_FADELEVEL] = 0;
-    gTasks[newTaskId].data[TD_DELAY] = 8;
-    gTasks[newTaskId].data[TD_INTERVAL] = interval;
-    gTasks[newTaskId].data[TD_FRAMECOUNTER] = interval;
+    gTasks[newTaskId].tMainTaskId = taskId;
+    gTasks[newTaskId].tFadeLevel = 0;
+    gTasks[newTaskId].tDelay = 8;
+    gTasks[newTaskId].tUpdateInterval = interval;
+    gTasks[newTaskId].tFrameCounter = interval;
 }
 
 static void HandleFloorShadowFadeIn(u8 taskId)
 {
-    if (gTasks[taskId].data[TD_DELAY])
-        gTasks[taskId].data[TD_DELAY]--;
+    if (gTasks[taskId].tDelay)
+        gTasks[taskId].tDelay--;
     else
     {
-        if (gTasks[taskId].data[TD_FADELEVEL] == 0)
+        if (gTasks[taskId].tFadeLevel == 0)
             DestroyTask(taskId);
         else
         {
-            if (gTasks[taskId].data[TD_FRAMECOUNTER])
-                gTasks[taskId].data[TD_FRAMECOUNTER]--;
+            if (gTasks[taskId].tFrameCounter)
+                gTasks[taskId].tFrameCounter--;
             else
             {
-                gTasks[taskId].data[TD_FRAMECOUNTER] = gTasks[taskId].data[TD_INTERVAL];
-                gTasks[taskId].data[TD_FADELEVEL]--;
-                LoadPalette(&gUnknown_081E795C[gTasks[taskId].data[TD_FADELEVEL]], 1, 0x10);
+                gTasks[taskId].tFrameCounter = gTasks[taskId].tUpdateInterval;
+                gTasks[taskId].tFadeLevel--;
+                LoadPalette(&gUnknown_081E795C[gTasks[taskId].tFadeLevel], 1, 0x10);
             }
         }
     }
@@ -1583,12 +1605,18 @@ static void HandleFloorShadowFadeIn(u8 taskId)
 static void StartBackgroundFadeIn(u8 taskId, u8 interval)
 {
     u8 newTaskId = CreateTask(HandleFloorShadowFadeIn, 0);
-    gTasks[newTaskId].data[TD_PARENT_TASK_ID] = taskId;
-    gTasks[newTaskId].data[TD_FADELEVEL] = 8;
-    gTasks[newTaskId].data[TD_DELAY] = 8;
-    gTasks[newTaskId].data[TD_INTERVAL] = interval;
-    gTasks[newTaskId].data[TD_FRAMECOUNTER] = interval;
-}
+    gTasks[newTaskId].tMainTaskId = taskId;
+    gTasks[newTaskId].tFadeLevel = 8;
+    gTasks[newTaskId].tDelay = 8;
+    gTasks[newTaskId].tUpdateInterval = interval;
+    gTasks[newTaskId].tFrameCounter = interval;
+}
+
+#undef tMainTaskId
+#undef tFadeLevel
+#undef tDelay
+#undef tUpdateInterval
+#undef tFrameCounter
 
 static void CreateGenderMenu(u8 left, u8 top)
 {
diff --git a/src/pokemon_menu.c b/src/pokemon_menu.c
index 36144ae7c..d460833c3 100644
--- a/src/pokemon_menu.c
+++ b/src/pokemon_menu.c
@@ -779,7 +779,7 @@ static void sub_808AB34(u8 taskID)
 
 #undef tFieldMoveId
 
-void sub_808AB90(void)
+void FieldCallback_Teleport(void)
 {
     pal_fill_black();
     CreateTask(sub_808ABA8, 8);
@@ -814,7 +814,7 @@ static bool8 SetUpFieldMove_Surf(void)
 {
     if (PartyHasMonWithSurf() == TRUE && IsPlayerFacingSurfableFishableWater() == TRUE)
     {
-        gFieldCallback = sub_808AB90;
+        gFieldCallback = FieldCallback_Teleport;
         gUnknown_03005CE4 = sub_808AC2C;
         return TRUE;
     }
@@ -832,13 +832,13 @@ static bool8 SetUpFieldMove_Fly(void)
 {
     if (ShouldDoBrailleFlyEffect())
     {
-        gFieldCallback = sub_808AB90;
+        gFieldCallback = FieldCallback_Teleport;
         gUnknown_03005CE4 = DoBrailleFlyEffect;
         return TRUE;
     }
-    if (is_light_level_1_2_3_or_6(gMapHeader.mapType) == 1)
+    if (Overworld_MapTypeAllowsTeleportAndFly(gMapHeader.mapType) == TRUE)
     {
-        gFieldCallback = sub_808AB90;
+        gFieldCallback = FieldCallback_Teleport;
         gUnknown_03005CE4 = sub_808AC8C;
         return TRUE;
     }
@@ -884,7 +884,7 @@ static bool8 SetUpFieldMove_Dive(void)
     gFieldEffectArguments[1] = sub_8068F18();
     if (gFieldEffectArguments[1])
     {
-        gFieldCallback = sub_808AB90;
+        gFieldCallback = FieldCallback_Teleport;
         gUnknown_03005CE4 = sub_808ADAC;
         return TRUE;
     }
@@ -905,7 +905,7 @@ static bool8 SetUpFieldMove_Waterfall(void)
     if (MetatileBehavior_IsWaterfall(MapGridGetMetatileBehaviorAt(x, y)) == TRUE
         && IsPlayerSurfingNorth() == TRUE)
     {
-        gFieldCallback = sub_808AB90;
+        gFieldCallback = FieldCallback_Teleport;
         gUnknown_03005CE4 = sub_808AE08;
         return TRUE;
     }
diff --git a/src/region_map.c b/src/region_map.c
index 076dfecec..1d567fcf0 100644
--- a/src/region_map.c
+++ b/src/region_map.c
@@ -714,7 +714,7 @@ static void InitializeCursorPosition(void)
         return;
     }
 
-    switch (get_map_light_level_by_bank_and_number(gSaveBlock1.location.mapGroup, gSaveBlock1.location.mapNum) - 1)
+    switch (GetMapTypeByGroupAndId(gSaveBlock1.location.mapGroup, gSaveBlock1.location.mapNum) - 1)
     {
     default:
     case 0:
@@ -733,7 +733,7 @@ static void InitializeCursorPosition(void)
         break;
     case 3:
     case 6:
-        mapHeader = get_mapheader_by_bank_and_number(gSaveBlock1.warp4.mapGroup, gSaveBlock1.warp4.mapNum);
+        mapHeader = Overworld_GetMapHeaderByGroupAndId(gSaveBlock1.warp4.mapGroup, gSaveBlock1.warp4.mapNum);
         gRegionMap->mapSecId = mapHeader->regionMapSectionId;
         gRegionMap->playerIsInCave = TRUE;
         mapWidth = mapHeader->mapData->width;
@@ -742,7 +742,7 @@ static void InitializeCursorPosition(void)
         y = gSaveBlock1.warp4.y;
         break;
     case 8:
-        mapHeader = get_mapheader_by_bank_and_number(gSaveBlock1.warp2.mapGroup, gSaveBlock1.warp2.mapNum);
+        mapHeader = Overworld_GetMapHeaderByGroupAndId(gSaveBlock1.warp2.mapGroup, gSaveBlock1.warp2.mapNum);
         gRegionMap->mapSecId = mapHeader->regionMapSectionId;
         gRegionMap->playerIsInCave = TRUE;
         mapWidth = mapHeader->mapData->width;
@@ -758,12 +758,12 @@ static void InitializeCursorPosition(void)
             if (gRegionMap->mapSecId != MAPSEC_UNK_0x57)
             {
                 r4 = &gSaveBlock1.warp4;
-                mapHeader = get_mapheader_by_bank_and_number(r4->mapGroup, r4->mapNum);
+                mapHeader = Overworld_GetMapHeaderByGroupAndId(r4->mapGroup, r4->mapNum);
             }
             else
             {
                 r4 = &gSaveBlock1.warp2;
-                mapHeader = get_mapheader_by_bank_and_number(r4->mapGroup, r4->mapNum);
+                mapHeader = Overworld_GetMapHeaderByGroupAndId(r4->mapGroup, r4->mapNum);
                 gRegionMap->mapSecId = mapHeader->regionMapSectionId;
             }
             gRegionMap->playerIsInCave = FALSE;
@@ -850,7 +850,7 @@ static void sub_80FB600(void)
     default:
     case 0:
         {
-            struct MapHeader *mapHeader = get_mapheader_by_bank_and_number(mapGroup, mapNum);
+            struct MapHeader *mapHeader = Overworld_GetMapHeaderByGroupAndId(mapGroup, mapNum);
             u16 r1;
 
             gRegionMap->mapSecId = mapHeader->regionMapSectionId;
diff --git a/src/rom3.c b/src/rom3.c
index 3b4b6a941..3f4860ecc 100644
--- a/src/rom3.c
+++ b/src/rom3.c
@@ -1081,10 +1081,10 @@ void EmitFaintingCry(u8 a)
     PrepareBufferDataTransfer(a, gBattleBuffersTransferData, 4);
 }
 
-void EmitIntroSlide(u8 a, u8 b)
+void EmitIntroSlide(u8 a, u8 battleTerrain)
 {
     gBattleBuffersTransferData[0] = 46;
-    gBattleBuffersTransferData[1] = b;
+    gBattleBuffersTransferData[1] = battleTerrain;
     PrepareBufferDataTransfer(a, gBattleBuffersTransferData, 2);
 }
 
diff --git a/src/rom4.c b/src/rom4.c
index 69faec2ca..e1c8932b8 100644
--- a/src/rom4.c
+++ b/src/rom4.c
@@ -25,6 +25,7 @@
 #include "link.h"
 #include "load_save.h"
 #include "main.h"
+#include "map_constants.h"
 #include "map_name_popup.h"
 #include "menu.h"
 #include "metatile_behavior.h"
@@ -82,7 +83,7 @@ u8 gFieldLinkPlayerCount;
 extern u16 gUnknown_03004898;
 extern u16 gUnknown_0300489C;
 
-extern u8 EventScript_LeagueWhiteOut[];
+extern u8 S_WhiteOut[];
 extern u8 gUnknown_0819FC9F[];
 extern u8 SingleBattleColosseum_EventScript_1A436F[];
 extern u8 SingleBattleColosseum_EventScript_1A4379[];
@@ -110,12 +111,12 @@ extern void (*gUnknown_082166D8[])(struct LinkPlayerMapObject *, struct MapObjec
 extern struct MapData * const gMapAttributes[];
 extern struct MapHeader * const * const gMapGroups[];
 extern const struct WarpData gDummyWarpData;
-extern s32 gUnknown_0839ACE8;
+extern s32 gMaxFlashLevel;
 extern u32 gUnknown_08216694[];
 
-void DoWhiteOut(void)
+static void DoWhiteOut(void)
 {
-    ScriptContext2_RunNewScript(EventScript_LeagueWhiteOut);
+    ScriptContext2_RunNewScript(S_WhiteOut);
     gSaveBlock1.money /= 2;
     HealPlayerParty();
     sub_8053050();
@@ -133,8 +134,7 @@ void flag_var_implications_of_teleport_(void)
     FlagReset(SYS_USE_FLASH);
 }
 
-// not new_game
-void new_game(void)
+void Overworld_ResetStateAfterTeleport(void)
 {
     player_avatar_init_params_reset();
     FlagReset(SYS_CYCLING_ROAD);
@@ -215,15 +215,16 @@ void sub_8053154(void)
               gMapHeader.events->mapObjectCount * sizeof(struct MapObjectTemplate));
 }
 
-void sub_8053198(void)
+static void LoadSaveblockMapObjScripts(void)
 {
     struct MapObjectTemplate *mapObjectTemplates = gSaveBlock1.mapObjectTemplates;
     s32 i;
+
     for (i = 0; i < 64; i++)
         mapObjectTemplates[i].script = gMapHeader.events->mapObjects[i].script;
 }
 
-void update_saveblock1_field_object_coords(u8 localId, s16 x, s16 y)
+void Overworld_SaveMapObjCoords(u8 localId, s16 x, s16 y)
 {
     s32 i;
     for (i = 0; i < 64; i++)
@@ -233,28 +234,26 @@ void update_saveblock1_field_object_coords(u8 localId, s16 x, s16 y)
         {
             mapObjectTemplate->x = x;
             mapObjectTemplate->y = y;
-            break;
+            return;
         }
     }
 }
 
-void update_saveblock1_field_object_movement_behavior(u8 localId, u8 movementType)
+void Overworld_SaveMapObjMovementType(u8 localId, u8 movementType)
 {
-    s32 i = 0;
-    struct MapObjectTemplate *mapObjectTemplate = gSaveBlock1.mapObjectTemplates;
-    do
+    s32 i;
+    for (i = 0; i < 64; i++)
     {
+        struct MapObjectTemplate *mapObjectTemplate = &gSaveBlock1.mapObjectTemplates[i];
         if (mapObjectTemplate->localId == localId)
         {
             mapObjectTemplate->movementType = movementType;
-            break;
+            return;
         }
-        mapObjectTemplate++;
-        i++;
-    } while (i < 64);
+    }
 }
 
-void mapdata_load_assets_to_gpu_and_full_redraw(void)
+static void mapdata_load_assets_to_gpu_and_full_redraw(void)
 {
     move_tilemap_camera_to_upper_left_corner();
     copy_map_tileset1_tileset2_to_vram(gMapHeader.mapData);
@@ -263,7 +262,7 @@ void mapdata_load_assets_to_gpu_and_full_redraw(void)
     cur_mapheader_run_tileset_funcs_after_some_cpuset();
 }
 
-struct MapData *get_mapdata_header(void)
+static struct MapData *get_mapdata_header(void)
 {
     u16 mapDataId = gSaveBlock1.mapDataId;
     if (mapDataId)
@@ -271,7 +270,7 @@ struct MapData *get_mapdata_header(void)
     return NULL;
 }
 
-void warp_shift(void)
+static void warp_shift(void)
 {
     gUnknown_020297F0 = gSaveBlock1.location;
     gSaveBlock1.location = gUnknown_020297F8;
@@ -279,7 +278,7 @@ void warp_shift(void)
     gUnknown_02029808 = gDummyWarpData;
 }
 
-void warp_set(struct WarpData *warp, s8 mapGroup, s8 mapNum, s8 warpId, s8 x, s8 y)
+static void warp_set(struct WarpData *warp, s8 mapGroup, s8 mapNum, s8 warpId, s8 x, s8 y)
 {
     warp->mapGroup = mapGroup;
     warp->mapNum = mapNum;
@@ -288,7 +287,7 @@ void warp_set(struct WarpData *warp, s8 mapGroup, s8 mapNum, s8 warpId, s8 x, s8
     warp->y = y;
 }
 
-bool32 warp_data_is_not_neg_1(struct WarpData *warp)
+static bool32 warp_data_is_not_neg_1(struct WarpData *warp)
 {
     if (warp->mapGroup != -1)
         return FALSE;
@@ -303,26 +302,26 @@ bool32 warp_data_is_not_neg_1(struct WarpData *warp)
     return TRUE;
 }
 
-struct MapHeader *const get_mapheader_by_bank_and_number(u16 mapGroup, u16 mapNum)
+struct MapHeader *const Overworld_GetMapHeaderByGroupAndId(u16 mapGroup, u16 mapNum)
 {
     return gMapGroups[mapGroup][mapNum];
 }
 
 struct MapHeader *const warp1_get_mapheader(void)
 {
-    return get_mapheader_by_bank_and_number(gUnknown_020297F8.mapGroup, gUnknown_020297F8.mapNum);
+    return Overworld_GetMapHeaderByGroupAndId(gUnknown_020297F8.mapGroup, gUnknown_020297F8.mapNum);
 }
 
-void set_current_map_header_from_sav1_save_old_name(void)
+static void set_current_map_header_from_sav1_save_old_name(void)
 {
-    gMapHeader = *get_mapheader_by_bank_and_number(gSaveBlock1.location.mapGroup, gSaveBlock1.location.mapNum);
+    gMapHeader = *Overworld_GetMapHeaderByGroupAndId(gSaveBlock1.location.mapGroup, gSaveBlock1.location.mapNum);
     gSaveBlock1.mapDataId = gMapHeader.mapDataId;
     gMapHeader.mapData = get_mapdata_header();
 }
 
-void sub_805338C(void)
+static void LoadSaveblockMapHeader(void)
 {
-    gMapHeader = *get_mapheader_by_bank_and_number(gSaveBlock1.location.mapGroup, gSaveBlock1.location.mapNum);
+    gMapHeader = *Overworld_GetMapHeaderByGroupAndId(gSaveBlock1.location.mapGroup, gSaveBlock1.location.mapNum);
     gMapHeader.mapData = get_mapdata_header();
 }
 
@@ -398,9 +397,9 @@ void sub_8053588(u8 a1)
 
 void sub_80535C4(s16 a1, s16 a2)
 {
-    u8 v4 = sav1_map_get_light_level();
-    u8 v5 = get_map_light_level_by_bank_and_number(gUnknown_020297F8.mapGroup, gUnknown_020297F8.mapNum);
-    if (is_light_level_1_2_3_5_or_6(v4) && is_light_level_1_2_3_5_or_6(v5) != TRUE)
+    u8 v4 = Overworld_GetMapTypeOfSaveblockLocation();
+    u8 v5 = GetMapTypeByGroupAndId(gUnknown_020297F8.mapGroup, gUnknown_020297F8.mapNum);
+    if (is_map_type_1_2_3_5_or_6(v4) && is_map_type_1_2_3_5_or_6(v5) != TRUE)
         sub_805363C(gSaveBlock1.location.mapGroup, gSaveBlock1.location.mapNum, -1, a1 - 7, a2 - 6);
 }
 
@@ -482,7 +481,7 @@ struct MapConnection *sub_8053818(u8 dir)
 bool8 sub_8053850(u8 dir, u16 x, u16 y)
 {
     struct MapConnection *connection = sub_8053818(dir);
-    if (connection)
+    if (connection != NULL)
     {
         warp1_set(connection->mapGroup, connection->mapNum, -1, x, y);
     }
@@ -522,7 +521,7 @@ void sub_80538F0(u8 mapGroup, u8 mapNum)
     DoTimeBasedEvents();
     sub_80806E4();
     ChooseAmbientCrySpecies();
-    sub_8053C98();
+    SetDefaultFlashLevel();
     sav1_reset_battle_music_maybe();
     mapheader_run_script_with_tag_x3();
     not_trainer_hill_battle_pyramid();
@@ -548,8 +547,8 @@ void sub_8053994(u32 a1)
 
     set_current_map_header_from_sav1_save_old_name();
     sub_8053154();
-    v2 = is_light_level_1_2_3_5_or_6(gMapHeader.mapType);
-    v3 = is_light_level_8_or_9(gMapHeader.mapType);
+    v2 = is_map_type_1_2_3_5_or_6(gMapHeader.mapType);
+    v3 = Overworld_MapTypeIsIndoors(gMapHeader.mapType);
     ClearTempFieldEventData();
     ResetCyclingRoadChallengeData();
     prev_quest_postbuffer_cursor_backup_reset();
@@ -560,7 +559,7 @@ void sub_8053994(u32 a1)
     ChooseAmbientCrySpecies();
     if (v2)
         FlagReset(SYS_USE_FLASH);
-    sub_8053C98();
+    SetDefaultFlashLevel();
     sav1_reset_battle_music_maybe();
     mapheader_run_script_with_tag_x3();
     UpdateLocationHistoryForRoamer();
@@ -598,11 +597,11 @@ void walkrun_find_lowest_active_bit_in_bitfield(void)
 struct UnkPlayerStruct *sub_8053AA8(void)
 {
     struct UnkPlayerStruct playerStruct;
-    u8 light = sav1_map_get_light_level();
+    u8 mapType = Overworld_GetMapTypeOfSaveblockLocation();
     u16 v2 = cur_mapdata_block_role_at_screen_center_acc_to_sav1();
-    u8 v4 = sub_8053B00(&gUnknown_02029810, v2, light);
+    u8 v4 = sub_8053B00(&gUnknown_02029810, v2, mapType);
     playerStruct.player_field_0 = v4;
-    playerStruct.player_field_1 = sub_8053B60(&gUnknown_02029810, v4, v2, light);
+    playerStruct.player_field_1 = sub_8053B60(&gUnknown_02029810, v4, v2, mapType);
     gUnknown_02029810 = playerStruct;
     return &gUnknown_02029810;
 }
@@ -615,7 +614,7 @@ u8 sub_8053B00(struct UnkPlayerStruct *playerStruct, u16 a2, u8 a3)
         return 16;
     if (MetatileBehavior_IsSurfableWaterOrUnderwater(a2) == 1)
         return 8;
-    if (IsBikingAllowedByMap() != TRUE)
+    if (Overworld_IsBikeAllowedOnCurrentMap() != TRUE)
         return 1;
     if (playerStruct->player_field_0 == 2)
         return 2;
@@ -653,10 +652,12 @@ u16 cur_mapdata_block_role_at_screen_center_acc_to_sav1(void)
     return MapGridGetMetatileBehaviorAt(gSaveBlock1.pos.x + 7, gSaveBlock1.pos.y + 7);
 }
 
-bool32 IsBikingAllowedByMap(void)
+bool32 Overworld_IsBikeAllowedOnCurrentMap(void)
 {
     // is player in cycling road entrance?
-    if (gSaveBlock1.location.mapGroup == 29 && (gSaveBlock1.location.mapNum == 11 || gSaveBlock1.location.mapNum == 12))
+    if (gSaveBlock1.location.mapGroup == MAP_GROUP_ROUTE110_SEASIDE_CYCLING_ROAD_SOUTH_ENTRANCE
+     && (gSaveBlock1.location.mapNum == MAP_ID_ROUTE110_SEASIDE_CYCLING_ROAD_SOUTH_ENTRANCE
+      || gSaveBlock1.location.mapNum == MAP_ID_ROUTE110_SEASIDE_CYCLING_ROAD_NORTH_ENTRANCE))
         return TRUE;
 
     // is player indoor, in a secret base, or underwater?
@@ -667,37 +668,37 @@ bool32 IsBikingAllowedByMap(void)
     if (gMapHeader.mapType == MAP_TYPE_UNDERWATER)
         return FALSE;
 
-    // is player in SeafloorCavern_Room9?
-    if (gSaveBlock1.location.mapGroup == 24 && gSaveBlock1.location.mapNum == 36)
+    // Thou shalt not bike on the sacred resting grounds of Kyogre/Groudon.
+    if (gSaveBlock1.location.mapGroup == MAP_GROUP_SEAFLOOR_CAVERN_ROOM9
+     && gSaveBlock1.location.mapNum == MAP_ID_SEAFLOOR_CAVERN_ROOM9)
         return FALSE;
-
-    // is player in CaveOfOrigin_B4F?
-    if (gSaveBlock1.location.mapGroup == 24 && gSaveBlock1.location.mapNum == 42)
+    if (gSaveBlock1.location.mapGroup == MAP_GROUP_CAVE_OF_ORIGIN_B4F
+     && gSaveBlock1.location.mapNum == MAP_ID_CAVE_OF_ORIGIN_B4F)
         return FALSE;
 
     return TRUE;
 }
 
-void sub_8053C98(void)
+void SetDefaultFlashLevel(void)
 {
     if (!gMapHeader.cave)
-        gSaveBlock1.flashUsed = 0;
+        gSaveBlock1.flashLevel = 0;
     else if (FlagGet(SYS_USE_FLASH))
-        gSaveBlock1.flashUsed = 1;
+        gSaveBlock1.flashLevel = 1;
     else
-        gSaveBlock1.flashUsed = gUnknown_0839ACE8;
+        gSaveBlock1.flashLevel = gMaxFlashLevel;
 }
 
-void sub_8053CE4(s32 a1)
+void Overworld_SetFlashLevel(s32 flashLevel)
 {
-    if (a1 < 0 || a1 > gUnknown_0839ACE8)
-        a1 = 0;
-    gSaveBlock1.flashUsed = a1;
+    if (flashLevel < 0 || flashLevel > gMaxFlashLevel)
+        flashLevel = 0;
+    gSaveBlock1.flashLevel = flashLevel;
 }
 
-u8 sav1_get_flash_used_on_map(void)
+u8 Overworld_GetFlashLevel(void)
 {
-    return gSaveBlock1.flashUsed;
+    return gSaveBlock1.flashLevel;
 }
 
 void sub_8053D14(u16 mapDataId)
@@ -706,60 +707,62 @@ void sub_8053D14(u16 mapDataId)
     gMapHeader.mapData = get_mapdata_header();
 }
 
-bool16 sub_8053D30(struct WarpData *warp)
+static bool16 ShouldLegendaryMusicPlayAtLocation(struct WarpData *warp)
 {
     if (!FlagGet(SYS_WEATHER_CTRL))
         return FALSE;
-    if (warp->mapGroup != 0)
-        return FALSE;
-    switch (warp->mapNum)
+    if (warp->mapGroup == 0)
     {
-    case 5:
-    case 6:
-    case 7:
-    case 8:
-        return TRUE;
-    case 39:
-    case 40:
-    case 41:
-    case 42:
-    case 43:
-        return TRUE;
+        switch (warp->mapNum)
+        {
+        case MAP_ID_LILYCOVE_CITY:
+        case MAP_ID_MOSSDEEP_CITY:
+        case MAP_ID_SOOTOPOLIS_CITY:
+        case MAP_ID_EVER_GRANDE_CITY:
+            return TRUE;
+        case MAP_ID_ROUTE124:
+        case MAP_ID_ROUTE125:
+        case MAP_ID_ROUTE126:
+        case MAP_ID_ROUTE127:
+        case MAP_ID_ROUTE128:
+            return TRUE;
+        }
     }
     return FALSE;
 }
 
-bool16 sub_8053D6C(struct WarpData *warp)
+static bool16 IsInfiltratedWeatherInstitute(struct WarpData *warp)
 {
-    if (VarGet(0x40B3))
+    if (VarGet(VAR_WEATHER_INSTITUTE_CLEARED))
         return FALSE;
-    if (warp->mapGroup != 32)
+    if (warp->mapGroup != MAP_GROUP_ROUTE119_WEATHER_INSTITUTE_1F)
         return FALSE;
-    if (warp->mapNum == 0 || warp->mapNum == 1)
+    if (warp->mapNum == MAP_ID_ROUTE119_WEATHER_INSTITUTE_1F
+     || warp->mapNum == MAP_ID_ROUTE119_WEATHER_INSTITUTE_2F)
         return TRUE;
     return FALSE;
 }
 
-u16 sub_8053D9C(struct WarpData *warp)
+static u16 GetLocationMusic(struct WarpData *warp)
 {
-    if (sub_8053D30(warp) == TRUE)
+    if (ShouldLegendaryMusicPlayAtLocation(warp) == TRUE)
         return LEGENDARY_MUSIC;
-    else if (sub_8053D6C(warp) == TRUE)
+    else if (IsInfiltratedWeatherInstitute(warp) == TRUE)
         return BGM_TOZAN;
     else
-        return get_mapheader_by_bank_and_number(warp->mapGroup, warp->mapNum)->music;
+        return Overworld_GetMapHeaderByGroupAndId(warp->mapGroup, warp->mapNum)->music;
 }
 
 u16 sav1_map_get_music(void)
 {
     u16 music;
 
-    if (gSaveBlock1.location.mapGroup == 0
-     && gSaveBlock1.location.mapNum == 26
+    if (gSaveBlock1.location.mapGroup == MAP_GROUP_ROUTE111
+     && gSaveBlock1.location.mapNum == MAP_ID_ROUTE111
      && GetSav1Weather() == 8)
         return BGM_ASHROAD;
 
-    music = sub_8053D9C(&gSaveBlock1.location);
+    music = GetLocationMusic(&gSaveBlock1.location);
     if (music != 0x7FFF)
     {
         return music;
@@ -775,14 +778,15 @@ u16 sav1_map_get_music(void)
 
 u16 warp1_target_get_music(void)
 {
-    u16 music = sub_8053D9C(&gUnknown_020297F8);
+    u16 music = GetLocationMusic(&gUnknown_020297F8);
     if (music != 0x7FFF)
     {
         return music;
     }
     else
     {
-        if (gSaveBlock1.location.mapGroup == 0 && gSaveBlock1.location.mapNum == 2)
+        if (gSaveBlock1.location.mapGroup == MAP_GROUP_MAUVILLE_CITY
+         && gSaveBlock1.location.mapNum == MAP_ID_MAUVILLE_CITY)
             return BGM_DOORO_X1;
         else
             return BGM_GRANROAD;
@@ -802,7 +806,7 @@ void sub_8053E90(void)
     {
         if (gSaveBlock1.battleMusic)
             music = gSaveBlock1.battleMusic;
-        else if (sav1_map_get_light_level() == 5)
+        else if (Overworld_GetMapTypeOfSaveblockLocation() == MAP_TYPE_UNDERWATER)
             music = BGM_DEEPDEEP;
         else if (TestPlayerAvatarFlags(PLAYER_AVATAR_FLAG_SURFING))
             music = BGM_NAMINORI;
@@ -852,17 +856,17 @@ void sub_8053F84(void)
         FadeOutAndPlayNewMapMusic(sav1_map_get_music(), 8);
 }
 
-void ChangeMapMusic(u16 newMusic)
+void Overworld_ChangeMusicTo(u16 newMusic)
 {
     u16 currentMusic = GetCurrentMapMusic();
     if (currentMusic != newMusic && currentMusic != LEGENDARY_MUSIC)
         FadeOutAndPlayNewMapMusic(newMusic, 8);
 }
 
-u8 is_warp1_light_level_8_or_9(void)
+u8 GetMapMusicFadeoutSpeed(void)
 {
     struct MapHeader *mapHeader = warp1_get_mapheader();
-    if (is_light_level_8_or_9(mapHeader->mapType) == TRUE)
+    if (Overworld_MapTypeIsIndoors(mapHeader->mapType) == TRUE)
         return 2;
     else
         return 4;
@@ -873,7 +877,7 @@ void sub_8053FF8(void)
     u16 music = warp1_target_get_music();
     if (FlagGet(SPECIAL_FLAG_1) != TRUE && music != GetCurrentMapMusic())
     {
-        u8 speed = is_warp1_light_level_8_or_9();
+        u8 speed = GetMapMusicFadeoutSpeed();
         FadeOutMapMusic(speed);
     }
 }
@@ -934,10 +938,14 @@ void UpdateAmbientCry(s16 *state, u16 *delayCounter)
 
 void ChooseAmbientCrySpecies(void)
 {
-    if ((gSaveBlock1.location.mapGroup == 0 && gSaveBlock1.location.mapNum == 45) && !IsMirageIslandPresent())
+    if ((gSaveBlock1.location.mapGroup == MAP_GROUP_ROUTE130
+     && gSaveBlock1.location.mapNum == MAP_ID_ROUTE130)
+     && !IsMirageIslandPresent())
     {
+        // Only play water pokemon cries on this route
+        // when Mirage Island is not present
         sIsAmbientCryWaterMon = TRUE;
-        sAmbientCrySpecies = GetMirageIslandMon();
+        sAmbientCrySpecies = GetLocalWaterMon();
     }
     else
     {
@@ -945,45 +953,53 @@ void ChooseAmbientCrySpecies(void)
     }
 }
 
-u8 get_map_light_level_by_bank_and_number(s8 mapGroup, s8 mapNum)
+u8 GetMapTypeByGroupAndId(s8 mapGroup, s8 mapNum)
 {
-    return get_mapheader_by_bank_and_number(mapGroup, mapNum)->mapType;
+    return Overworld_GetMapHeaderByGroupAndId(mapGroup, mapNum)->mapType;
 }
 
-u8 get_map_light_level_from_warp(struct WarpData *warp)
+u8 GetMapTypeByWarpData(struct WarpData *warp)
 {
-    return get_map_light_level_by_bank_and_number(warp->mapGroup, warp->mapNum);
+    return GetMapTypeByGroupAndId(warp->mapGroup, warp->mapNum);
 }
 
-u8 sav1_map_get_light_level(void)
+u8 Overworld_GetMapTypeOfSaveblockLocation(void)
 {
-    return get_map_light_level_from_warp(&gSaveBlock1.location);
+    return GetMapTypeByWarpData(&gSaveBlock1.location);
 }
 
-u8 get_map_light_from_warp0(void)
+u8 get_map_type_from_warp0(void)
 {
-    return get_map_light_level_from_warp(&gUnknown_020297F0);
+    return GetMapTypeByWarpData(&gUnknown_020297F0);
 }
 
-bool8 is_light_level_1_2_3_5_or_6(u8 a1)
+bool8 is_map_type_1_2_3_5_or_6(u8 mapType)
 {
-    if (a1 == 3 || a1 == 1 || a1 == 5 || a1 == 2 || a1 == 6)
+    if (mapType == MAP_TYPE_ROUTE
+     || mapType == MAP_TYPE_TOWN
+     || mapType == MAP_TYPE_UNDERWATER
+     || mapType == MAP_TYPE_CITY
+     || mapType == MAP_TYPE_6)
         return TRUE;
     else
         return FALSE;
 }
 
-bool8 is_light_level_1_2_3_or_6(u8 a1)
+bool8 Overworld_MapTypeAllowsTeleportAndFly(u8 mapType)
 {
-    if (a1 == 3 || a1 == 1 || a1 == 6 || a1 == 2)
+    if (mapType == MAP_TYPE_ROUTE
+     || mapType == MAP_TYPE_TOWN
+     || mapType == MAP_TYPE_6
+     || mapType == MAP_TYPE_CITY)
         return TRUE;
     else
         return FALSE;
 }
 
-bool8 is_light_level_8_or_9(u8 a1)
+bool8 Overworld_MapTypeIsIndoors(u8 mapType)
 {
-    if (a1 == 8 || a1 == 9)
+    if (mapType == MAP_TYPE_INDOOR
+     || mapType == MAP_TYPE_SECRET_BASE)
         return TRUE;
     else
         return FALSE;
@@ -991,17 +1007,17 @@ bool8 is_light_level_8_or_9(u8 a1)
 
 u8 unref_sub_8054260(void)
 {
-    return get_mapheader_by_bank_and_number(gSaveBlock1.warp2.mapGroup, gSaveBlock1.warp2.mapNum)->regionMapSectionId;
+    return Overworld_GetMapHeaderByGroupAndId(gSaveBlock1.warp2.mapGroup, gSaveBlock1.warp2.mapNum)->regionMapSectionId;
 }
 
 u8 sav1_map_get_name(void)
 {
-    return get_mapheader_by_bank_and_number(gSaveBlock1.location.mapGroup, gSaveBlock1.location.mapNum)->regionMapSectionId;
+    return Overworld_GetMapHeaderByGroupAndId(gSaveBlock1.location.mapGroup, gSaveBlock1.location.mapNum)->regionMapSectionId;
 }
 
 u8 sav1_map_get_battletype(void)
 {
-    return get_mapheader_by_bank_and_number(gSaveBlock1.location.mapGroup, gSaveBlock1.location.mapNum)->battleType;
+    return Overworld_GetMapHeaderByGroupAndId(gSaveBlock1.location.mapGroup, gSaveBlock1.location.mapNum)->battleType;
 }
 
 void ResetSafariZoneFlag_(void)
@@ -1263,8 +1279,8 @@ void CB2_ContinueSavedGame(void)
     FieldClearVBlankHBlankCallbacks();
     StopMapMusic();
     ResetSafariZoneFlag_();
-    sub_805338C();
-    sub_8053198();
+    LoadSaveblockMapHeader();
+    LoadSaveblockMapObjScripts();
     UnfreezeMapObjects();
     DoTimeBasedEvents();
     sub_805308C();
@@ -1315,7 +1331,7 @@ void VBlankCB_Field(void)
 
 void sub_8054814(void)
 {
-    u8 val = sav1_get_flash_used_on_map();
+    u8 val = Overworld_GetFlashLevel();
     if (val)
     {
         sub_80815E0(val);
diff --git a/src/rom6.c b/src/rom6.c
index 702e48c69..9308dfe0c 100644
--- a/src/rom6.c
+++ b/src/rom6.c
@@ -120,7 +120,7 @@ bool8 SetUpFieldMove_RockSmash(void)
 {
     if (npc_before_player_of_type(0x56) == TRUE)
     {
-        gFieldCallback = sub_808AB90;
+        gFieldCallback = FieldCallback_Teleport;
         gUnknown_03005CE4 = sub_810B53C;
         return TRUE;
     }
@@ -157,7 +157,7 @@ int SetUpFieldMove_Dig(void)
 {
     if (sub_80CA1C8() == TRUE)
     {
-        gFieldCallback = sub_808AB90;
+        gFieldCallback = FieldCallback_Teleport;
         gUnknown_03005CE4 = sub_810B5D8;
         return TRUE;
     }
diff --git a/src/scrcmd.c b/src/scrcmd.c
index 813e041e1..6a746b65d 100644
--- a/src/scrcmd.c
+++ b/src/scrcmd.c
@@ -567,8 +567,8 @@ bool8 ScrCmd_lighten(struct ScriptContext *ctx)
 
 bool8 ScrCmd_darken(struct ScriptContext *ctx)
 {
-    u16 value = VarGet(ScriptReadHalfword(ctx));
-    sub_8053CE4(value);
+    u16 flashLevel = VarGet(ScriptReadHalfword(ctx));
+    Overworld_SetFlashLevel(flashLevel);
     return FALSE;
 }
 
@@ -870,7 +870,7 @@ bool8 ScrCmd_fadedefault(struct ScriptContext *ctx)
 
 bool8 ScrCmd_fademusic(struct ScriptContext *ctx)
 {
-    ChangeMapMusic(ScriptReadHalfword(ctx));
+    Overworld_ChangeMusicTo(ScriptReadHalfword(ctx));
     return FALSE;
 }
 
@@ -996,7 +996,7 @@ bool8 ScrCmd_movespriteperm(struct ScriptContext *ctx)
     u16 v1 = VarGet(ScriptReadHalfword(ctx));
     u16 v2 = VarGet(ScriptReadHalfword(ctx));
     u32 v3 = VarGet(ScriptReadHalfword(ctx));
-    update_saveblock1_field_object_coords(v1, v2, v3);
+    Overworld_SaveMapObjCoords(v1, v2, v3);
     return FALSE;
 }
 
@@ -1066,7 +1066,7 @@ bool8 ScrCmd_spritebehave(struct ScriptContext *ctx)
 {
     u16 v1 = VarGet(ScriptReadHalfword(ctx));
     u8 v2 = ScriptReadByte(ctx);
-    update_saveblock1_field_object_movement_behavior(v1, v2);
+    Overworld_SaveMapObjMovementType(v1, v2);
     return FALSE;
 }
 
diff --git a/src/script.c b/src/script.c
index 394085d4a..f049b96fc 100644
--- a/src/script.c
+++ b/src/script.c
@@ -228,16 +228,16 @@ void ScriptContext2_RunNewScript(const u8 *ptr)
         ;
 }
 
-u8 *mapheader_get_tagged_pointer(u8 tag)
+static u8 *mapheader_get_tagged_pointer(u8 tag)
 {
     u8 *mapScripts = gMapHeader.mapScripts;
 
-    if (!mapScripts)
+    if (mapScripts == NULL)
         return NULL;
 
     while (1)
     {
-        if (!*mapScripts)
+        if (*mapScripts == 0)
             return NULL;
         if (*mapScripts == tag)
         {
@@ -248,14 +248,14 @@ u8 *mapheader_get_tagged_pointer(u8 tag)
     }
 }
 
-void mapheader_run_script_by_tag(u8 tag)
+static void mapheader_run_script_by_tag(u8 tag)
 {
     u8 *ptr = mapheader_get_tagged_pointer(tag);
     if (ptr)
         ScriptContext2_RunNewScript(ptr);
 }
 
-u8 *mapheader_get_first_match_from_tagged_ptr_list(u8 tag)
+static u8 *mapheader_get_first_match_from_tagged_ptr_list(u8 tag)
 {
     u8 *ptr = mapheader_get_tagged_pointer(tag);
 
@@ -316,7 +316,7 @@ void mapheader_run_first_tag4_script_list_match(void)
         ScriptContext2_RunNewScript(ptr);
 }
 
-u32 CalculateRamScriptChecksum(void)
+static u32 CalculateRamScriptChecksum(void)
 {
     u32 i;
     u32 sum = 0;
diff --git a/src/time_events.c b/src/time_events.c
index e1b9a2e9e..ab3d6b9d4 100644
--- a/src/time_events.c
+++ b/src/time_events.c
@@ -81,7 +81,7 @@ void UpdateShoalTideFlag(void)
         1,
     };
 
-    if (is_light_level_1_2_3_5_or_6(get_map_light_from_warp0()))
+    if (is_map_type_1_2_3_5_or_6(get_map_type_from_warp0()))
     {
         RtcCalcLocalTime();
         if (tide[gLocalTime.hours])
diff --git a/src/wild_encounter.c b/src/wild_encounter.c
index 23e74561c..f7f005737 100644
--- a/src/wild_encounter.c
+++ b/src/wild_encounter.c
@@ -5,6 +5,7 @@
 #include "event_data.h"
 #include "field_player_avatar.h"
 #include "fieldmap.h"
+#include "map_constants.h"
 #include "metatile_behavior.h"
 #include "pokeblock.h"
 #include "rng.h"
@@ -2952,7 +2953,8 @@ static bool8 CheckFeebas(void)
     u8 route119section = 0;
     u16 waterTileNum;
 
-    if (gSaveBlock1.location.mapGroup == 0 && gSaveBlock1.location.mapNum == 0x22)
+    if (gSaveBlock1.location.mapGroup == MAP_GROUP_ROUTE119
+     && gSaveBlock1.location.mapNum == MAP_ID_ROUTE119)
     {
         GetXYCoordsOneStepInFrontOfPlayer(&x, &y);
         x -= 7;
@@ -3497,7 +3499,7 @@ u16 GetLocalWildMon(bool8 *isWaterMon)
     }
 }
 
-u16 GetMirageIslandMon(void)
+u16 GetLocalWaterMon(void)
 {
     u16 headerNum = GetCurrentMapWildMonHeader();