What it does
Apple Acid is a Grass-type special move with power 90 in Champions (boosted from the base game's 80). Every hit, not sometimes — every hit, the target's Special Defense drops by one stage. There's no chance roll on the debuff. It's baked in.
A one-stage Special Defense drop means every special hit the target takes afterward is more painful. In doubles, where you often have two attackers firing at the same target, the cascade is fast. Hit Apple Acid on the first turn, and your partner's special move that same turn benefits from the lowered SpDef.
Grass coverage super-effectively hits Water, Rock, and Ground types. Against Water-types especially, Apple Acid is working double duty: super-effective damage plus a guaranteed SpDef cut, all in one move. That's a lot of value per action.
100% accuracy. Clean to use.
Who runs it
Appletun at 94% — this is Appletun's exclusive signature move. No other Pokémon in Champions gets it. So 'who runs it' has one answer, and it's Appletun.
Appletun is Grass/Dragon with solid Special Attack but low Speed. That Speed stat matters for how you use Apple Acid in doubles: if Appletun moves after your partner, the SpDef drop only benefits moves on the following turn. Get Appletun moving first — either by facing a slower target or running Trick Room — and the drop affects your partner's same-turn attacks.
How to use it
Apple Acid targets a single Pokémon. In doubles, pick the target you intend to work through over multiple turns — something tanky on the special side, something that your other attackers are also pointing at.
Because the SpDef drop is guaranteed, you can plan the debuff stack methodically. Turn one, the target is at -1 SpDef. If it stays in, turn two brings -2. Your partner's special hits keep scaling up. The math compounds faster than it does with a chance-based drop.
SpDef drops reset on switch-out. When the opponent swaps the debuffed target for a fresh Pokémon, you start over on that new target. Watch for pivot plays and adjust your targeting — don't waste Apple Acid on a target that's about to be swapped out.
Tips & strategy
Pair Appletun with a second special attacker to maximize the SpDef drop. The guaranteed nature of the debuff turns it from a bonus into a win condition when you can follow with high-power special coverage the same turn or the next.
Against Water-types, Apple Acid is the ideal move: super-effective damage plus guaranteed SpDef cut means even a bulky Water-type loses its special-side defensive integrity fast. Two turns of Apple Acid into a Water Stall wall, and your partner's special coverage can blow through what was previously a problem.
Appletun's low Speed is the main liability. Without Trick Room, it typically moves after most threats. Something on the field to protect Appletun — or support that reverses Speed priority — helps it stay on the field long enough to stack multiple SpDef drops and convert the accumulated pressure.