From Bulbapedia, the community-driven Pokémon encyclopedia.
Priority refers to the order in which Trainers' commands are followed during a battle. Under normal circumstances, the priority of a move used in a battle is determined by the Speed statistic of the Pokémon using the move. However, a move may have a different priority value, which can cause that move to always go before or after ordinary moves. Using items and switching Pokémon will almost always precede a Pokémon's move.
Each move has a hidden priority value in the game data, ranging from +7 to -7. Most moves are ordinary, and have 0 priority. Moves that always go before ordinary priority moves have increased priority and priority values greater than zero. Examples include moves such as Quick Attack and ExtremeSpeed. Moves that always go after ordinary priority moves have decreased priority and priority values less than zero. Examples of decreased priority moves are Counter and Roar. Moves with effects that last an entire turn, such as Protect or Magic Coat, have much higher priority to ensure that the move is used at the start of the turn.
Moves that have the same priority are said to be in the same priority bracket. When two moves of equal priority, such as when both Aqua Jet and Bullet Punch, are used in the same turn, the Pokémon with the higher Speed will act first.
Move priority is not changed by the effects of Trick Room, which only reverses the order of moves within a priority bracket. Increased priority moves still go first, and decreased priority moves still go last.
When a Pokémon uses a move, some held items and abilities cause it to go last within its priority bracket, ignoring even Trick Room. The items Full Incense and Lagging Tail and the ability Stall have this effect, but do not change the priority of any moves.
|| Switching out, rotating, using items, escaping
|| Helping Hand
|| Protect*, Magic Coat, Snatch
|| Detect, Endure, Follow Me, Protect*, Fake Out*, Quick Guard, Rage Powder, Wide Guard
|| Feint, ExtremeSpeed*
|| Aqua Jet, Bide*, Bullet Punch, ExtremeSpeed*, Fake Out*, Ice Shard, Mach Punch, Quick Attack, Shadow Sneak, Sucker Punch, Vacuum Wave, Ally Switch
|| All other moves
|| Vital Throw
|| Focus Punch
|| Avalanche, Revenge*
|| Counter, Mirror Coat
|| Roar*, Whirlwind*, Dragon Tail, Circle Throw
|| Trick Room, Wonder Room, Magic Room, fleeing
- Since Focus Punch has a higher priority than Avalanche, Revenge, Dragon Tail, Circle Throw, and Counter, they are unable to break the focus of a Pokémon using Focus Punch. Thus, they are the only five attacks that can strike a Pokémon in the same turn it successfully uses Focus Punch.
- Until Generation IV, there were no moves that had a priority of +2, -4, or -7, and there still has yet to be a move with a priority of -2.