When the AI uses stat-lowering or status-inflicting moves, like Screech or Sleep Powder, it has an additional 25% chance to fail on top of the usual accuracy and evasion modifiers. This is caused by four different clauses in [engine/battle/effect_commands.asm](../blob/master/engine/battle/effect_commands.asm), all of which will need deleting.


## Contents

1. [`BattleCommand_StatDown`](#1-battlecommand_statdown)
2. [`BattleCommand_SleepTarget`](#2-battlecommand_sleeptarget)
3. [`BattleCommand_Poison`](#3-battlecommand_poison)
4. [`BattleCommand_Paralyze`](#4-battlecommand_paralyze)


## 1. `BattleCommand_StatDown`

```diff
 ; Sharply lower the stat if applicable.
 	ld a, [wLoweredStat]
 	and $f0
-	jr z, .ComputerMiss
+	jr z, .GotAmountToLower
 	dec b
-	jr nz, .ComputerMiss
+	jr nz, .GotAmountToLower
 	inc b

-.ComputerMiss:
-; Computer opponents have a 25% chance of failing.
-	ldh a, [hBattleTurn]
-	and a
-	jr z, .DidntMiss
-
-	ld a, [wLinkMode]
-	and a
-	jr nz, .DidntMiss
-
-	ld a, [wInBattleTowerBattle]
-	and a
-	jr nz, .DidntMiss
-
-; Lock-On still always works.
-	ld a, [wPlayerSubStatus5]
-	bit SUBSTATUS_LOCK_ON, a
-	jr nz, .DidntMiss
-
-; Attacking moves that also lower accuracy are unaffected.
-	ld a, BATTLE_VARS_MOVE_EFFECT
-	call GetBattleVar
-	cp EFFECT_ACCURACY_DOWN_HIT
-	jr z, .DidntMiss
-
-	call BattleRandom
-	cp 25 percent + 1 ; 25% chance AI fails
-	jr c, .Failed

-.DidntMiss:
+.GotAmountToLower:
 	call CheckSubstituteOpp
 	jr nz, .Failed

 	...
```


## 2. `BattleCommand_SleepTarget`

```diff
 	ld hl, DidntAffect1Text
-	call .CheckAIRandomFail
-	jr c, .fail

 	...

-.CheckAIRandomFail:
-	; Enemy turn
-	ldh a, [hBattleTurn]
-	and a
-	jr z, .dont_fail
-
-	; Not in link battle
-	ld a, [wLinkMode]
-	and a
-	jr nz, .dont_fail
-
-	ld a, [wInBattleTowerBattle]
-	and a
-	jr nz, .dont_fail
-
-	; Not locked-on by the enemy
-	ld a, [wPlayerSubStatus5]
-	bit SUBSTATUS_LOCK_ON, a
-	jr nz, .dont_fail
-
-	call BattleRandom
-	cp 25 percent + 1 ; 25% chance AI fails
-	ret c
-
-.dont_fail
-	xor a
-	ret
```


## 3. `BattleCommand_Poison`

```diff
-	ldh a, [hBattleTurn]
-	and a
-	jr z, .dont_sample_failure
-
-	ld a, [wLinkMode]
-	and a
-	jr nz, .dont_sample_failure
-
-	ld a, [wInBattleTowerBattle]
-	and a
-	jr nz, .dont_sample_failure
-
-	ld a, [wPlayerSubStatus5]
-	bit SUBSTATUS_LOCK_ON, a
-	jr nz, .dont_sample_failure
-
-	call BattleRandom
-	cp 25 percent + 1 ; 25% chance AI fails
-	jr c, .failed
-
-.dont_sample_failure
 	...
```


## 4. `BattleCommand_Paralyze`

```diff
 .no_item_protection
-	ldh a, [hBattleTurn]
-	and a
-	jr z, .dont_sample_failure
-
-	ld a, [wLinkMode]
-	and a
-	jr nz, .dont_sample_failure
-
-	ld a, [wInBattleTowerBattle]
-	and a
-	jr nz, .dont_sample_failure
-
-	ld a, [wPlayerSubStatus5]
-	bit SUBSTATUS_LOCK_ON, a
-	jr nz, .dont_sample_failure
-
-	call BattleRandom
-	cp 25 percent + 1 ; 25% chance AI fails
-	jr c, .failed
-
-.dont_sample_failure
 	...
```

That's it! Note that there is no `BattleCommand_Burn` or `BattleCommand_Freeze`.