diff --git a/asm/field_effect.s b/asm/field_effect.s
deleted file mode 100644
index 6ec6d639b..000000000
--- a/asm/field_effect.s
+++ /dev/null
@@ -1,491 +0,0 @@
-	.include "constants/gba_constants.inc"
-	.include "constants/species_constants.inc"
-	.include "asm/macros.inc"
-
-	.syntax unified
-
-	.text
-
-	thumb_func_start FieldEffectStart
-FieldEffectStart: @ 8085668
-	push {r4,r5,lr}
-	sub sp, 0x8
-	adds r4, r0, 0
-	lsls r4, 24
-	lsrs r4, 24
-	adds r0, r4, 0
-	bl FieldEffectActiveListAdd
-	ldr r0, _080856A8 @ =gFieldEffectScriptPointers
-	lsls r4, 2
-	adds r4, r0
-	ldr r0, [r4]
-	str r0, [sp]
-	add r4, sp, 0x4
-	ldr r5, _080856AC @ =gUnknown_0839F0D4
-_08085686:
-	ldr r0, [sp]
-	ldrb r0, [r0]
-	lsls r0, 2
-	adds r0, r5
-	ldr r2, [r0]
-	mov r0, sp
-	adds r1, r4, 0
-	bl _call_via_r2
-	lsls r0, 24
-	cmp r0, 0
-	bne _08085686
-	ldr r0, [sp, 0x4]
-	add sp, 0x8
-	pop {r4,r5}
-	pop {r1}
-	bx r1
-	.align 2, 0
-_080856A8: .4byte gFieldEffectScriptPointers
-_080856AC: .4byte gUnknown_0839F0D4
-	thumb_func_end FieldEffectStart
-
-	thumb_func_start FieldEffectCmd_loadtiles
-FieldEffectCmd_loadtiles: @ 80856B0
-	push {lr}
-	ldr r1, [r0]
-	adds r1, 0x1
-	str r1, [r0]
-	bl FieldEffectScript_LoadTiles
-	movs r0, 0x1
-	pop {r1}
-	bx r1
-	thumb_func_end FieldEffectCmd_loadtiles
-
-	thumb_func_start FieldEffectCmd_loadfadedpal
-FieldEffectCmd_loadfadedpal: @ 80856C4
-	push {lr}
-	ldr r1, [r0]
-	adds r1, 0x1
-	str r1, [r0]
-	bl FieldEffectScript_LoadFadedPalette
-	movs r0, 0x1
-	pop {r1}
-	bx r1
-	thumb_func_end FieldEffectCmd_loadfadedpal
-
-	thumb_func_start FieldEffectCmd_loadpal
-FieldEffectCmd_loadpal: @ 80856D8
-	push {lr}
-	ldr r1, [r0]
-	adds r1, 0x1
-	str r1, [r0]
-	bl FieldEffectScript_LoadPalette
-	movs r0, 0x1
-	pop {r1}
-	bx r1
-	thumb_func_end FieldEffectCmd_loadpal
-
-	thumb_func_start FieldEffectCmd_callnative
-FieldEffectCmd_callnative: @ 80856EC
-	push {lr}
-	ldr r2, [r0]
-	adds r2, 0x1
-	str r2, [r0]
-	bl FieldEffectScript_CallNative
-	movs r0, 0x1
-	pop {r1}
-	bx r1
-	thumb_func_end FieldEffectCmd_callnative
-
-	thumb_func_start sub_8085700
-sub_8085700: @ 8085700
-	movs r0, 0
-	bx lr
-	thumb_func_end sub_8085700
-
-	thumb_func_start FieldEffectCmd_loadgfx_callnative
-FieldEffectCmd_loadgfx_callnative: @ 8085704
-	push {r4,r5,lr}
-	adds r4, r0, 0
-	adds r5, r1, 0
-	ldr r0, [r4]
-	adds r0, 0x1
-	str r0, [r4]
-	adds r0, r4, 0
-	bl FieldEffectScript_LoadTiles
-	adds r0, r4, 0
-	bl FieldEffectScript_LoadFadedPalette
-	adds r0, r4, 0
-	adds r1, r5, 0
-	bl FieldEffectScript_CallNative
-	movs r0, 0x1
-	pop {r4,r5}
-	pop {r1}
-	bx r1
-	thumb_func_end FieldEffectCmd_loadgfx_callnative
-
-	thumb_func_start FieldEffectCmd_loadtiles_callnative
-FieldEffectCmd_loadtiles_callnative: @ 808572C
-	push {r4,r5,lr}
-	adds r4, r0, 0
-	adds r5, r1, 0
-	ldr r0, [r4]
-	adds r0, 0x1
-	str r0, [r4]
-	adds r0, r4, 0
-	bl FieldEffectScript_LoadTiles
-	adds r0, r4, 0
-	adds r1, r5, 0
-	bl FieldEffectScript_CallNative
-	movs r0, 0x1
-	pop {r4,r5}
-	pop {r1}
-	bx r1
-	thumb_func_end FieldEffectCmd_loadtiles_callnative
-
-	thumb_func_start FieldEffectCmd_loadfadedpal_callnative
-FieldEffectCmd_loadfadedpal_callnative: @ 8085750
-	push {r4,r5,lr}
-	adds r4, r0, 0
-	adds r5, r1, 0
-	ldr r0, [r4]
-	adds r0, 0x1
-	str r0, [r4]
-	adds r0, r4, 0
-	bl FieldEffectScript_LoadFadedPalette
-	adds r0, r4, 0
-	adds r1, r5, 0
-	bl FieldEffectScript_CallNative
-	movs r0, 0x1
-	pop {r4,r5}
-	pop {r1}
-	bx r1
-	thumb_func_end FieldEffectCmd_loadfadedpal_callnative
-
-	thumb_func_start FieldEffectScript_ReadWord
-FieldEffectScript_ReadWord: @ 8085774
-	ldr r2, [r0]
-	ldrb r0, [r2]
-	ldrb r1, [r2, 0x1]
-	lsls r1, 8
-	adds r0, r1
-	ldrb r1, [r2, 0x2]
-	lsls r1, 16
-	adds r0, r1
-	ldrb r1, [r2, 0x3]
-	lsls r1, 24
-	adds r0, r1
-	bx lr
-	thumb_func_end FieldEffectScript_ReadWord
-
-	thumb_func_start FieldEffectScript_LoadTiles
-FieldEffectScript_LoadTiles: @ 808578C
-	push {r4,r5,lr}
-	adds r4, r0, 0
-	bl FieldEffectScript_ReadWord
-	adds r5, r0, 0
-	ldrh r0, [r5, 0x6]
-	bl GetSpriteTileStartByTag
-	lsls r0, 16
-	ldr r1, _080857B8 @ =0xffff0000
-	cmp r0, r1
-	bne _080857AA
-	adds r0, r5, 0
-	bl LoadSpriteSheet
-_080857AA:
-	ldr r0, [r4]
-	adds r0, 0x4
-	str r0, [r4]
-	pop {r4,r5}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_080857B8: .4byte 0xffff0000
-	thumb_func_end FieldEffectScript_LoadTiles
-
-	thumb_func_start FieldEffectScript_LoadFadedPalette
-FieldEffectScript_LoadFadedPalette: @ 80857BC
-	push {r4,r5,lr}
-	adds r5, r0, 0
-	bl FieldEffectScript_ReadWord
-	adds r4, r0, 0
-	bl LoadSpritePalette
-	ldrh r0, [r4, 0x4]
-	bl IndexOfSpritePaletteTag
-	lsls r0, 24
-	lsrs r0, 24
-	bl sub_807D78C
-	ldr r0, [r5]
-	adds r0, 0x4
-	str r0, [r5]
-	pop {r4,r5}
-	pop {r0}
-	bx r0
-	thumb_func_end FieldEffectScript_LoadFadedPalette
-
-	thumb_func_start FieldEffectScript_LoadPalette
-FieldEffectScript_LoadPalette: @ 80857E4
-	push {r4,lr}
-	adds r4, r0, 0
-	bl FieldEffectScript_ReadWord
-	bl LoadSpritePalette
-	ldr r0, [r4]
-	adds r0, 0x4
-	str r0, [r4]
-	pop {r4}
-	pop {r0}
-	bx r0
-	thumb_func_end FieldEffectScript_LoadPalette
-
-	thumb_func_start FieldEffectScript_CallNative
-FieldEffectScript_CallNative: @ 80857FC
-	push {r4,r5,lr}
-	adds r4, r0, 0
-	adds r5, r1, 0
-	bl FieldEffectScript_ReadWord
-	bl _call_via_r0
-	str r0, [r5]
-	ldr r0, [r4]
-	adds r0, 0x4
-	str r0, [r4]
-	pop {r4,r5}
-	pop {r0}
-	bx r0
-	thumb_func_end FieldEffectScript_CallNative
-
-	thumb_func_start FieldEffectFreeGraphicsResources
-FieldEffectFreeGraphicsResources: @ 8085818
-	push {r4,r5,lr}
-	adds r1, r0, 0
-	adds r1, 0x40
-	ldrh r5, [r1]
-	ldrb r4, [r0, 0x5]
-	lsrs r4, 4
-	bl DestroySprite
-	adds r0, r5, 0
-	bl FieldEffectFreeTilesIfUnused
-	adds r0, r4, 0
-	bl FieldEffectFreePaletteIfUnused
-	pop {r4,r5}
-	pop {r0}
-	bx r0
-	thumb_func_end FieldEffectFreeGraphicsResources
-
-	thumb_func_start FieldEffectStop
-FieldEffectStop: @ 808583C
-	push {r4,lr}
-	lsls r4, r1, 24
-	lsrs r4, 24
-	bl FieldEffectFreeGraphicsResources
-	adds r0, r4, 0
-	bl FieldEffectActiveListRemove
-	pop {r4}
-	pop {r0}
-	bx r0
-	thumb_func_end FieldEffectStop
-
-	thumb_func_start FieldEffectFreeTilesIfUnused
-FieldEffectFreeTilesIfUnused: @ 8085854
-	push {r4,r5,lr}
-	lsls r0, 16
-	lsrs r4, r0, 16
-	adds r0, r4, 0
-	bl GetSpriteTileTagByTileStart
-	lsls r0, 16
-	lsrs r3, r0, 16
-	ldr r0, _080858B0 @ =0x0000ffff
-	cmp r3, r0
-	beq _080858A8
-	movs r2, 0
-	ldr r5, _080858B4 @ =gSprites
-_0808586E:
-	lsls r0, r2, 4
-	adds r0, r2
-	lsls r0, 2
-	adds r1, r0, r5
-	adds r0, r1, 0
-	adds r0, 0x3E
-	ldrb r0, [r0]
-	lsls r0, 31
-	cmp r0, 0
-	beq _08085898
-	adds r0, r1, 0
-	adds r0, 0x3F
-	ldrb r0, [r0]
-	lsls r0, 25
-	cmp r0, 0
-	bge _08085898
-	adds r0, r1, 0
-	adds r0, 0x40
-	ldrh r0, [r0]
-	cmp r4, r0
-	beq _080858A8
-_08085898:
-	adds r0, r2, 0x1
-	lsls r0, 24
-	lsrs r2, r0, 24
-	cmp r2, 0x3F
-	bls _0808586E
-	adds r0, r3, 0
-	bl FreeSpriteTilesByTag
-_080858A8:
-	pop {r4,r5}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_080858B0: .4byte 0x0000ffff
-_080858B4: .4byte gSprites
-	thumb_func_end FieldEffectFreeTilesIfUnused
-
-	thumb_func_start FieldEffectFreePaletteIfUnused
-FieldEffectFreePaletteIfUnused: @ 80858B8
-	push {r4-r6,lr}
-	lsls r0, 24
-	lsrs r4, r0, 24
-	adds r0, r4, 0
-	bl GetSpritePaletteTagByPaletteNum
-	lsls r0, 16
-	lsrs r5, r0, 16
-	ldr r0, _08085908 @ =0x0000ffff
-	cmp r5, r0
-	beq _08085900
-	movs r2, 0
-	ldr r6, _0808590C @ =gSprites
-	adds r3, r4, 0
-_080858D4:
-	lsls r0, r2, 4
-	adds r0, r2
-	lsls r0, 2
-	adds r1, r0, r6
-	adds r0, r1, 0
-	adds r0, 0x3E
-	ldrb r0, [r0]
-	lsls r0, 31
-	cmp r0, 0
-	beq _080858F0
-	ldrb r0, [r1, 0x5]
-	lsrs r0, 4
-	cmp r0, r3
-	beq _08085900
-_080858F0:
-	adds r0, r2, 0x1
-	lsls r0, 24
-	lsrs r2, r0, 24
-	cmp r2, 0x3F
-	bls _080858D4
-	adds r0, r5, 0
-	bl FreeSpritePaletteByTag
-_08085900:
-	pop {r4-r6}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_08085908: .4byte 0x0000ffff
-_0808590C: .4byte gSprites
-	thumb_func_end FieldEffectFreePaletteIfUnused
-
-	thumb_func_start FieldEffectActiveListClear
-FieldEffectActiveListClear: @ 8085910
-	push {r4,lr}
-	movs r2, 0
-	ldr r4, _08085930 @ =gUnknown_030006E0
-	movs r3, 0xFF
-_08085918:
-	adds r0, r2, r4
-	ldrb r1, [r0]
-	orrs r1, r3
-	strb r1, [r0]
-	adds r0, r2, 0x1
-	lsls r0, 24
-	lsrs r2, r0, 24
-	cmp r2, 0x1F
-	bls _08085918
-	pop {r4}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_08085930: .4byte gUnknown_030006E0
-	thumb_func_end FieldEffectActiveListClear
-
-	thumb_func_start FieldEffectActiveListAdd
-FieldEffectActiveListAdd: @ 8085934
-	push {r4,lr}
-	lsls r0, 24
-	lsrs r3, r0, 24
-	movs r2, 0
-	ldr r4, _0808594C @ =gUnknown_030006E0
-_0808593E:
-	adds r1, r2, r4
-	ldrb r0, [r1]
-	cmp r0, 0xFF
-	bne _08085950
-	strb r3, [r1]
-	b _0808595A
-	.align 2, 0
-_0808594C: .4byte gUnknown_030006E0
-_08085950:
-	adds r0, r2, 0x1
-	lsls r0, 24
-	lsrs r2, r0, 24
-	cmp r2, 0x1F
-	bls _0808593E
-_0808595A:
-	pop {r4}
-	pop {r0}
-	bx r0
-	thumb_func_end FieldEffectActiveListAdd
-
-	thumb_func_start FieldEffectActiveListRemove
-FieldEffectActiveListRemove: @ 8085960
-	push {r4,r5,lr}
-	lsls r0, 24
-	lsrs r3, r0, 24
-	movs r2, 0
-	ldr r4, _0808597C @ =gUnknown_030006E0
-	movs r5, 0xFF
-_0808596C:
-	adds r1, r2, r4
-	ldrb r0, [r1]
-	cmp r0, r3
-	bne _08085980
-	orrs r0, r5
-	strb r0, [r1]
-	b _0808598A
-	.align 2, 0
-_0808597C: .4byte gUnknown_030006E0
-_08085980:
-	adds r0, r2, 0x1
-	lsls r0, 24
-	lsrs r2, r0, 24
-	cmp r2, 0x1F
-	bls _0808596C
-_0808598A:
-	pop {r4,r5}
-	pop {r0}
-	bx r0
-	thumb_func_end FieldEffectActiveListRemove
-
-	thumb_func_start FieldEffectActiveListContains
-FieldEffectActiveListContains: @ 8085990
-	push {lr}
-	lsls r0, 24
-	lsrs r2, r0, 24
-	movs r1, 0
-	ldr r3, _080859A8 @ =gUnknown_030006E0
-_0808599A:
-	adds r0, r1, r3
-	ldrb r0, [r0]
-	cmp r0, r2
-	bne _080859AC
-	movs r0, 0x1
-	b _080859B8
-	.align 2, 0
-_080859A8: .4byte gUnknown_030006E0
-_080859AC:
-	adds r0, r1, 0x1
-	lsls r0, 24
-	lsrs r1, r0, 24
-	cmp r1, 0x1F
-	bls _0808599A
-	movs r0, 0
-_080859B8:
-	pop {r1}
-	bx r1
-	thumb_func_end FieldEffectActiveListContains
-
-	.align 2, 0 @ Don't pad with nop.
diff --git a/data/data2.s b/data/data2.s
index 320dfdf2f..e5dd9110f 100644
--- a/data/data2.s
+++ b/data/data2.s
@@ -11263,12 +11263,12 @@ gDarknessFieldMoveStreaksTilemap:: @ 839EE54
 	.incbin "graphics/misc/darkness_field_move_streaks_map.bin"
 
 	.align 2
-gUnknown_0839F0D4:: @ 839F0D4
+gFieldEffectScriptFuncs:: @ 839F0D4
 	.4byte FieldEffectCmd_loadtiles
 	.4byte FieldEffectCmd_loadfadedpal
 	.4byte FieldEffectCmd_loadpal
 	.4byte FieldEffectCmd_callnative
-	.4byte sub_8085700
+	.4byte FieldEffectCmd_end
 	.4byte FieldEffectCmd_loadgfx_callnative
 	.4byte FieldEffectCmd_loadtiles_callnative
 	.4byte FieldEffectCmd_loadfadedpal_callnative
diff --git a/ld_script.txt b/ld_script.txt
index 9dd33a58e..c5fbd3bfc 100644
--- a/ld_script.txt
+++ b/ld_script.txt
@@ -103,7 +103,7 @@ SECTIONS {
         asm/trainer_see.o(.text);
         src/fldeff_emotion.o(.text);
         src/wild_encounter.o(.text);
-        asm/field_effect.o(.text);
+        src/field_effect.o(.text);
         asm/rom_80859BC.o(.text);
         src/option_menu.o(.text);
         src/pokedex.o(.text);
diff --git a/src/field_effect.c b/src/field_effect.c
new file mode 100644
index 000000000..97301ab50
--- /dev/null
+++ b/src/field_effect.c
@@ -0,0 +1,218 @@
+#include "global.h"
+#include "sprite.h"
+
+typedef bool8 (*FldEffCmd)(u8 **, u32 *);
+
+static u8 sActiveList[32];
+
+extern u8 *gFieldEffectScriptPointers[];
+
+extern FldEffCmd gFieldEffectScriptFuncs[];
+
+void FieldEffectScript_LoadTiles(u8 **script);
+void FieldEffectScript_LoadFadedPalette(u8 **script);
+void FieldEffectScript_LoadPalette(u8 **script);
+void FieldEffectScript_CallNative(u8 **script, u32 *val);
+void FieldEffectFreeGraphicsResources(struct Sprite *sprite);
+void FieldEffectStop(struct Sprite *sprite, u8 id);
+void FieldEffectFreeTilesIfUnused(u16 tileStart);
+void FieldEffectFreePaletteIfUnused(u8 paletteNum);
+void FieldEffectActiveListClear(void);
+void FieldEffectActiveListAdd(u8 id);
+void FieldEffectActiveListRemove(u8 id);
+
+u32 FieldEffectStart(u8 id)
+{
+    u8 *script;
+    u32 val;
+
+    FieldEffectActiveListAdd(id);
+
+    script = gFieldEffectScriptPointers[id];
+
+    while (gFieldEffectScriptFuncs[*script](&script, &val))
+        ;
+
+    return val;
+}
+
+bool8 FieldEffectCmd_loadtiles(u8 **script, u32 *val)
+{
+    (*script)++;
+    FieldEffectScript_LoadTiles(script);
+    return TRUE;
+}
+
+bool8 FieldEffectCmd_loadfadedpal(u8 **script, u32 *val)
+{
+    (*script)++;
+    FieldEffectScript_LoadFadedPalette(script);
+    return TRUE;
+}
+
+bool8 FieldEffectCmd_loadpal(u8 **script, u32 *val)
+{
+    (*script)++;
+    FieldEffectScript_LoadPalette(script);
+    return TRUE;
+}
+
+bool8 FieldEffectCmd_callnative(u8 **script, u32 *val)
+{
+    (*script)++;
+    FieldEffectScript_CallNative(script, val);
+    return TRUE;
+}
+
+bool8 FieldEffectCmd_end(u8 **script, u32 *val)
+{
+    return FALSE;
+}
+
+bool8 FieldEffectCmd_loadgfx_callnative(u8 **script, u32 *val)
+{
+    (*script)++;
+    FieldEffectScript_LoadTiles(script);
+    FieldEffectScript_LoadFadedPalette(script);
+    FieldEffectScript_CallNative(script, val);
+    return TRUE;
+}
+
+bool8 FieldEffectCmd_loadtiles_callnative(u8 **script, u32 *val)
+{
+    (*script)++;
+    FieldEffectScript_LoadTiles(script);
+    FieldEffectScript_CallNative(script, val);
+    return TRUE;
+}
+
+bool8 FieldEffectCmd_loadfadedpal_callnative(u8 **script, u32 *val)
+{
+    (*script)++;
+    FieldEffectScript_LoadFadedPalette(script);
+    FieldEffectScript_CallNative(script, val);
+    return TRUE;
+}
+
+u32 FieldEffectScript_ReadWord(u8 **script)
+{
+    return (*script)[0]
+         + ((*script)[1] << 8)
+         + ((*script)[2] << 16)
+         + ((*script)[3] << 24);
+}
+
+void FieldEffectScript_LoadTiles(u8 **script)
+{
+    struct SpriteSheet *sheet = (struct SpriteSheet *)FieldEffectScript_ReadWord(script);
+    if (GetSpriteTileStartByTag(sheet->tag) == 0xFFFF)
+        LoadSpriteSheet(sheet);
+    (*script) += 4;
+}
+
+void FieldEffectScript_LoadFadedPalette(u8 **script)
+{
+    struct SpritePalette *palette = (struct SpritePalette *)FieldEffectScript_ReadWord(script);
+    LoadSpritePalette(palette);
+    sub_807D78C(IndexOfSpritePaletteTag(palette->tag));
+    (*script) += 4;
+}
+
+void FieldEffectScript_LoadPalette(u8 **script)
+{
+    struct SpritePalette *palette = (struct SpritePalette *)FieldEffectScript_ReadWord(script);
+    LoadSpritePalette(palette);
+    (*script) += 4;
+}
+
+void FieldEffectScript_CallNative(u8 **script, u32 *val)
+{
+    u32 (*func)(void) = (u32 (*)(void))FieldEffectScript_ReadWord(script);
+    *val = func();
+    (*script) += 4;
+}
+
+void FieldEffectFreeGraphicsResources(struct Sprite *sprite)
+{
+    u16 sheetTileStart = sprite->sheetTileStart;
+    u32 paletteNum = sprite->oam.paletteNum;
+    DestroySprite(sprite);
+    FieldEffectFreeTilesIfUnused(sheetTileStart);
+    FieldEffectFreePaletteIfUnused(paletteNum);
+}
+
+void FieldEffectStop(struct Sprite *sprite, u8 id)
+{
+    FieldEffectFreeGraphicsResources(sprite);
+    FieldEffectActiveListRemove(id);
+}
+
+void FieldEffectFreeTilesIfUnused(u16 tileStart)
+{
+    u8 i;
+    u16 tag = GetSpriteTileTagByTileStart(tileStart);
+
+    if (tag != 0xFFFF)
+    {
+        for (i = 0; i < MAX_SPRITES; i++)
+            if (gSprites[i].inUse && gSprites[i].usingSheet && tileStart == gSprites[i].sheetTileStart)
+                return;
+        FreeSpriteTilesByTag(tag);
+    }
+}
+
+void FieldEffectFreePaletteIfUnused(u8 paletteNum)
+{
+    u8 i;
+    u16 tag = GetSpritePaletteTagByPaletteNum(paletteNum);
+
+    if (tag != 0xFFFF)
+    {
+        for (i = 0; i < MAX_SPRITES; i++)
+            if (gSprites[i].inUse && gSprites[i].oam.paletteNum == paletteNum)
+                return;
+        FreeSpritePaletteByTag(tag);
+    }
+}
+
+void FieldEffectActiveListClear(void)
+{
+    u8 i;
+    for (i = 0; i < ARRAY_COUNT(sActiveList); i++)
+        sActiveList[i] = 0xFF;
+}
+
+void FieldEffectActiveListAdd(u8 id)
+{
+    u8 i;
+    for (i = 0; i < ARRAY_COUNT(sActiveList); i++)
+    {
+        if (sActiveList[i] == 0xFF)
+        {
+            sActiveList[i] = id;
+            return;
+        }
+    }
+}
+
+void FieldEffectActiveListRemove(u8 id)
+{
+    u8 i;
+    for (i = 0; i < ARRAY_COUNT(sActiveList); i++)
+    {
+        if (sActiveList[i] == id)
+        {
+            sActiveList[i] = 0xFF;
+            return;
+        }
+    }
+}
+
+bool8 FieldEffectActiveListContains(u8 id)
+{
+    u8 i;
+    for (i = 0; i < ARRAY_COUNT(sActiveList); i++)
+        if (sActiveList[i] == id)
+            return TRUE;
+    return FALSE;
+}
diff --git a/sym_bss.txt b/sym_bss.txt
index f8e3ea706..c7e0b5d6e 100644
--- a/sym_bss.txt
+++ b/sym_bss.txt
@@ -92,8 +92,7 @@ gUnknown_030005A6: @ 30005A6
 gUnknown_030006DC: @ 30006DC
 	.space 0x4
 
-gUnknown_030006E0: @ 30006E0
-	.space 0x20
+	.include "src/field_effect.o"
 
 gUnknown_03000700: @ 3000700
 	.space 0x1