diff --git a/asm/macros/battle_script.inc b/asm/macros/battle_script.inc
index 0285b0f323..dd4deaad79 100644
--- a/asm/macros/battle_script.inc
+++ b/asm/macros/battle_script.inc
@@ -401,8 +401,9 @@
 	.byte \param1
 	.endm
 
-	.macro nop_4A
+	.macro sethealblock ptr
 	.byte 0x4a
+	.4byte \ptr
 	.endm
 
 	.macro returnatktoball
diff --git a/data/battle_scripts_1.s b/data/battle_scripts_1.s
index a5b43daf87..e4a5d2ee9a 100644
--- a/data/battle_scripts_1.s
+++ b/data/battle_scripts_1.s
@@ -57,7 +57,7 @@ gBattleScriptsForMoveEffects:: @ 82D86A8
 	.4byte BattleScript_EffectSuperFang
 	.4byte BattleScript_EffectDragonRage
 	.4byte BattleScript_EffectTrap
-	.4byte BattleScript_EffectPlaceholder43
+	.4byte BattleScript_EffectHealBlock
 	.4byte BattleScript_EffectDoubleHit
 	.4byte BattleScript_EffectRecoilIfMiss
 	.4byte BattleScript_EffectMist
@@ -540,6 +540,18 @@ BattleScript_CaptivateCheckAcc:
 	accuracycheck BattleScript_PrintMoveMissed, ACC_CURR_MOVE
 	goto BattleScript_StatDownFromAttackString
 	
+BattleScript_EffectHealBlock:
+	attackcanceler
+	accuracycheck BattleScript_PrintMoveMissed, ACC_CURR_MOVE
+	attackstring
+	ppreduce
+	sethealblock BattleScript_ButItFailed
+	attackanimation
+	waitanimation
+	printstring STRINGID_PKMNPREVENTEDFROMHEALING
+	waitmessage 0x40
+	goto BattleScript_MoveEnd
+	
 BattleScript_EffectHitEscape:
 	attackcanceler
 	accuracycheck BattleScript_PrintMoveMissed, ACC_CURR_MOVE
@@ -583,7 +595,6 @@ BattleScript_HitEscapeEnd:
 	end
 
 BattleScript_EffectAlwaysHit:
-BattleScript_EffectPlaceholder43:
 BattleScript_EffectEvasionDownHit:
 BattleScript_EffectVitalThrow:
 BattleScript_EffectUnused60:
@@ -1875,7 +1886,7 @@ BattleScript_EffectMeanLook::
 	attackcanceler
 	attackstring
 	ppreduce
-	accuracycheck BattleScript_ButItFailed, NO_ACC_CALC
+	accuracycheck BattleScript_ButItFailed, NO_ACC_CALC_CHECK_LOCK_ON
 	jumpifstatus2 BS_TARGET, STATUS2_ESCAPE_PREVENTION, BattleScript_ButItFailed
 	jumpifstatus2 BS_TARGET, STATUS2_SUBSTITUTE, BattleScript_ButItFailed
 	attackanimation
diff --git a/include/constants/battle_move_effects.h b/include/constants/battle_move_effects.h
index 329cd0a999..4c94337abf 100644
--- a/include/constants/battle_move_effects.h
+++ b/include/constants/battle_move_effects.h
@@ -44,7 +44,7 @@
 #define EFFECT_SUPER_FANG 40
 #define EFFECT_DRAGON_RAGE 41
 #define EFFECT_TRAP 42
-#define EFFECT_PLACEHOLDER_43 43
+#define EFFECT_HEAL_BLOCK 43
 #define EFFECT_DOUBLE_HIT 44
 #define EFFECT_RECOIL_IF_MISS 45
 #define EFFECT_MIST 46
diff --git a/include/constants/battle_script_commands.h b/include/constants/battle_script_commands.h
index fdf68fba60..98964c3bf0 100644
--- a/include/constants/battle_script_commands.h
+++ b/include/constants/battle_script_commands.h
@@ -47,7 +47,6 @@
 #define BS_OPPONENT2                14
 
 // atk 01, accuracy calc
-#define NO_ACC_CALC 0xFFFE
 #define NO_ACC_CALC_CHECK_LOCK_ON 0xFFFF
 #define ACC_CURR_MOVE 0
 
diff --git a/include/data/battle_moves.h b/include/data/battle_moves.h
index 731d14f269..78cd16fe68 100644
--- a/include/data/battle_moves.h
+++ b/include/data/battle_moves.h
@@ -4528,7 +4528,7 @@ const struct BattleMove gBattleMoves[MOVES_COUNT_GEN6] =
 		.split = SPLIT_SPECIAL,
 	},
 	{ // MOVE_HEAL_BLOCK
-		.effect = EFFECT_PLACEHOLDER_209, // Needs a custom move effect
+		.effect = EFFECT_HEAL_BLOCK,
 		.power = 0,
 		.type = TYPE_PSYCHIC,
 		.accuracy = 100,
@@ -5812,7 +5812,7 @@ const struct BattleMove gBattleMoves[MOVES_COUNT_GEN6] =
 		.split = SPLIT_STATUS,
 	},
 	{ // MOVE_HEAVY_SLAM
-		.effect = EFFECT_PLACEHOLDER_209, // Needs a custom move effect
+		.effect = EFFECT_HEAT_CRASH,
 		.power = 1,
 		.type = TYPE_STEEL,
 		.accuracy = 100,
@@ -5980,7 +5980,7 @@ const struct BattleMove gBattleMoves[MOVES_COUNT_GEN6] =
 		.split = SPLIT_SPECIAL,
 	},
 	{ // MOVE_CHIP_AWAY
-		.effect = EFFECT_HIT
+		.effect = EFFECT_HIT,
 		.power = 70,
 		.type = TYPE_NORMAL,
 		.accuracy = 100,
@@ -6220,7 +6220,7 @@ const struct BattleMove gBattleMoves[MOVES_COUNT_GEN6] =
 		.split = SPLIT_SPECIAL,
 	},
 	{ // MOVE_WATER_PLEDGE
-		.effect = EFFECT_PLEDGE
+		.effect = EFFECT_PLEDGE,
 		.power = 80,
 		.type = TYPE_WATER,
 		.accuracy = 100,
@@ -6232,7 +6232,7 @@ const struct BattleMove gBattleMoves[MOVES_COUNT_GEN6] =
 		.split = SPLIT_SPECIAL,
 	},
 	{ // MOVE_FIRE_PLEDGE
-		.effect = EFFECT_PLEDGE
+		.effect = EFFECT_PLEDGE,
 		.power = 80,
 		.type = TYPE_FIRE,
 		.accuracy = 100,
@@ -6244,7 +6244,7 @@ const struct BattleMove gBattleMoves[MOVES_COUNT_GEN6] =
 		.split = SPLIT_SPECIAL,
 	},
 	{ // MOVE_GRASS_PLEDGE
-		.effect = EFFECT_PLEDGE
+		.effect = EFFECT_PLEDGE,
 		.power = 80,
 		.type = TYPE_GRASS,
 		.accuracy = 100,
@@ -6448,7 +6448,7 @@ const struct BattleMove gBattleMoves[MOVES_COUNT_GEN6] =
 		.split = SPLIT_SPECIAL,
 	},
 	{ // MOVE_STEAMROLLER
-		.effect = EFFECT_PLACEHOLDER_209, // Needs a custom move effect
+		.effect = EFFECT_FLINCH_MINIMIZE_HIT,
 		.power = 65,
 		.type = TYPE_BUG,
 		.accuracy = 100,
@@ -6496,7 +6496,7 @@ const struct BattleMove gBattleMoves[MOVES_COUNT_GEN6] =
 		.split = SPLIT_SPECIAL,
 	},
 	{ // MOVE_TAIL_SLAP
-		.effect = EFFECT_PLACEHOLDER_209, // Needs a custom move effect (different percentages for hitting compared to doubleslap)
+		.effect = EFFECT_MULTI_HIT,
 		.power = 25,
 		.type = TYPE_NORMAL,
 		.accuracy = 85,
@@ -7036,7 +7036,7 @@ const struct BattleMove gBattleMoves[MOVES_COUNT_GEN6] =
 		.split = SPLIT_SPECIAL,
 	},
 	{ // MOVE_BOOMBURST
-		.effect = EFFECT_PLACEHOLDER_209, // Needs a custom move effect (Doesn't affect pokemon with SOUNDPROOF)
+		.effect = EFFECT_HIT,
 		.power = 140,
 		.type = TYPE_NORMAL,
 		.accuracy = 100,
@@ -7084,7 +7084,7 @@ const struct BattleMove gBattleMoves[MOVES_COUNT_GEN6] =
 		.split = SPLIT_STATUS,
 	},
 	{ // MOVE_CONFIDE
-		.effect = EFFECT_PLACEHOLDER_209, // Needs a custom move effect
+		.effect = EFFECT_SPECIAL_ATTACK_DOWN,
 		.power = 0,
 		.type = TYPE_NORMAL,
 		.accuracy = 0,
diff --git a/src/battle_message.c b/src/battle_message.c
index a04f904044..d64b0dba1a 100644
--- a/src/battle_message.c
+++ b/src/battle_message.c
@@ -575,8 +575,8 @@ static const u8 sText_ReflectTargetsType[] =_("{B_ATK_NAME_WITH_PREFIX}’s type
 static const u8 sText_TransferHeldItem[] =_("{B_DEF_NAME_WITH_PREFIX} recieved {B_LAST_ITEM}\nfrom {B_ATK_NAME_WITH_PREFIX}");
 static const u8 sText_EmbargoEnds[] = _("{B_DEF_NAME_WITH_PREFIX}can\nuse items again!");
 static const u8 sText_MagnetRiseEnds[] = _("{B_ATK_NAME_WITH_PREFIX}’s electromagnetism\nwore off!");
-static const u8 sText_HealBlockEnds[] = _("{B_DEF_NAME_WITH_PREFIX}’s Heal Block\nwore off!");
-static const u8 sText_TelekinesisEnds[] = _("{B_DEF_NAME_WITH_PREFIX} was freed\nfrom the telekinesis!");
+static const u8 sText_HealBlockEnds[] = _("{B_ATK_NAME_WITH_PREFIX}’s Heal Block\nwore off!");
+static const u8 sText_TelekinesisEnds[] = _("{B_ATK_NAME_WITH_PREFIX} was freed\nfrom the telekinesis!");
 static const u8 sText_TailwindEnds[] = _("{B_ATK_TEAM}’s tailwind\n petered out!");
 static const u8 sText_LuckyChantEnds[] = _("{B_ATK_TEAM}’s Lucky Chant\n wore off!");
 static const u8 sText_TrickRoomEnds[] = _("The twisted dimensions returned to\nnormal!");
diff --git a/src/battle_script_commands.c b/src/battle_script_commands.c
index b7f7d55b68..1aef220a79 100644
--- a/src/battle_script_commands.c
+++ b/src/battle_script_commands.c
@@ -166,7 +166,7 @@ static void atk46_playanimation2(void);
 static void atk47_setgraphicalstatchangevalues(void);
 static void atk48_playstatchangeanimation(void);
 static void atk49_moveend(void);
-static void atk4A_nop(void);
+static void atk4A_sethealblock(void);
 static void atk4B_returnatktoball(void);
 static void atk4C_getswitchedmondata(void);
 static void atk4D_switchindataupdate(void);
@@ -424,7 +424,7 @@ void (* const gBattleScriptingCommandsTable[])(void) =
     atk47_setgraphicalstatchangevalues,
     atk48_playstatchangeanimation,
     atk49_moveend,
-    atk4A_nop,
+    atk4A_sethealblock,
     atk4B_returnatktoball,
     atk4C_getswitchedmondata,
     atk4D_switchindataupdate,
@@ -1150,11 +1150,11 @@ static void atk01_accuracycheck(void)
 {
     u16 move = T2_READ_16(gBattlescriptCurrInstr + 5);
 
-    if (move == 0xFFFE || move == 0xFFFF)
+    if (move == NO_ACC_CALC_CHECK_LOCK_ON || gBattleMoves[move].accuracy == 0)
     {
-        if (gStatuses3[gBattlerTarget] & STATUS3_ALWAYS_HITS && move == 0xFFFF && gDisableStructs[gBattlerTarget].battlerWithSureHit == gBattlerAttacker)
+        if (gStatuses3[gBattlerTarget] & STATUS3_ALWAYS_HITS && gDisableStructs[gBattlerTarget].battlerWithSureHit == gBattlerAttacker)
             gBattlescriptCurrInstr += 7;
-        else if (gStatuses3[gBattlerTarget] & (STATUS3_ON_AIR | STATUS3_UNDERGROUND | STATUS3_UNDERWATER))
+        else if (gStatuses3[gBattlerTarget] & (STATUS3_SEMI_INVULNERABLE))
             gBattlescriptCurrInstr = T1_READ_PTR(gBattlescriptCurrInstr + 1);
         else if (!JumpIfMoveAffectedByProtect(0))
             gBattlescriptCurrInstr += 7;
@@ -4356,9 +4356,18 @@ static void atk49_moveend(void)
         gBattlescriptCurrInstr += 3;
 }
 
-static void atk4A_nop(void)
+static void atk4A_sethealblock(void)
 {
-    gBattlescriptCurrInstr++;
+    if (gStatuses3[gBattlerTarget] & STATUS3_HEAL_BLOCK)
+    {
+        gBattlescriptCurrInstr = T1_READ_PTR(gBattlescriptCurrInstr + 1);
+    }
+    else
+    {
+        gStatuses3[gBattlerTarget] |= STATUS3_HEAL_BLOCK;
+        gDisableStructs[gBattlerTarget].healBlockTimer = 5;
+        gBattlescriptCurrInstr += 5;
+    }
 }
 
 static void atk4B_returnatktoball(void)