Baneful Bunker protects the user from all effects of moves that target the user during the turn it is used, including damage. (This does not include damage afflicted by weather conditions it is susceptible to, or damage from a status ailment that it obtained on a previous turn.) Additionally, if Baneful Bunker blocks an attack that would make contact with the user, the attacker becomes poisoned (unless they're Poison- or Steel-type, or have Immunity, Comatose, or another status condition). However, if an attack is blocked by Baneful Bunker, the effects of the user's Rocky Helmet, Rough Skin, and Iron Barbs will not activate. If Sucker Punch is used on a Pokémon that has used Baneful Bunker, the move fails and the Pokémon does not get poisoned.
Using Protect, Detect, Endure, Spiky Shield, King's Shield, Baneful Bunker, Wide Guard, Quick Guard, Obstruct or Max Guard consecutively decreases the chance of success of Protect, Detect, Endure, Spiky Shield, King's Shield, Baneful Bunker, Obstruct, and Max Guard for each consecutive use.
It is an increased-priority move that will always go before attacks during the turn.
Feint, Phantom Force, Shadow Force, Hyperspace Hole, and Hyperspace Fury lift Baneful Bunker's protection for the rest of the turn. If a damaging Z-Move targets a Pokémon that used Baneful Bunker, the Z-Move will bypass Baneful Bunker but only do 25% of the original damage (the effects of Baneful Bunker are not lifted).
In addition to damaging Z-Moves, Baneful Bunker is unable to defend against any of the following moves:
Moves that target the user, moves that target the user and all allies, moves that target all Pokémon, and entry hazard moves cannot be blocked by Baneful Bunker.
If powered up by a Poisonium Z into Z-Baneful Bunker, the user's Defense stat rises by one stage.