Priority

Move Priority

Ever wonder why, despite the massive base speed difference in Pokemon, some Pokemon go first anyway? This has to do with Move Priority.

Priority Brackets

Moves of a higher Priority bracket always go first against moves of a slower priority bracket. If two Pokemon use a move within the same priority bracket the one with higher speed goes first.

+7 Using pursuit when your opponent switches ( Is +0 if they do not switch or use Baton pass ), Focus punches charge message appears before switching out.

+6 Switching out

+5 Helping Hand

+4 Snatch and Magic coat

+3 Protect, Follow me, Detect, Endure

+2 Feint

+1 Fake Out, Sucker Punch, Extreme Speed, Bullet punch, Mach punch, Vacuum wave, Ice Shard, Shadow Sneak, Quick attack.

=0 Sleep Talk, Me First, Metronome, Mirror move and EVERYTHING ELSE

-1 Vital Throw

-2 Focus punch

-3 Avalanche, Revenge

-4 Mirror Coat, Counter

-5 Roar, Whirlwind

-6 Trick Room

Points to take note

• Moves from a lower priority bracket always go last against moves of a higher priority.

• Quick claw ( when it activates roughly 1/6 of the time )allows you to go first within a speed bracket. So a =0 move will not out speed a +1 move if quick claw activates, but it will always beat any other =0 move unless the opponent is faster and activates their own quick claw.

• Pursuit is a =0 Priority attack unless the opponent switches, or is faster than you and uses U-turn. ( If they are slower, Pursuit stays at =0 )

• Lagging Tail and Full Incense make a move go last, within that speed bracket. If a =0 Move is used, you will always go last against another =0 move. Any moves of a lower priority bracket wills till go last. In the case of Lagging Tail/Full incense against Lagging Tail/Full incense the one with Higher speed goes last.

• Trick room reverses Speed calculations within a speed bracket, + Priority attacks will still go first, - Priority attacks will still go last. But in the case of same priority brackets ( the majority of attacks are =0 ) Speed is reversed, so slower Pokemon will go before faster ones. ( Essentially 100 speed versus 10 speed means that under normal circumstances the 100 speed Pokemon will go first, but under trick room the 10 speed Pokemon will go first. )

• Sleep Talk, Me First, Metronome, Mirror move make whatever move they copy/use/steal =0, so if you metronome or sleep talk a roar it's Priority becomes =0.

Sources

All of this has been tested in game by hand, except the [=0 "EVERYTHING ELSE"] which was taken from Smogon's priority list. - Enkidu.