What determines priority?


Assuming two players both execute a move at the same time that hits on the same frame, what determines which one wins out? Do both hit?

How about if the moves are different; i.e. specials vs normals, throws vs normals, jumping attacks vs normals, etc?


It’s all about hitboxes. Specials, normals, jumps, all irrelevant. If a throw is active on the same frame of a normal or special, and it’s not a normal-invulnerable command throw (EX throws), the throw will lose 100%. Certain moves are completely invulnerable during a portion of them (DPs, most ultras), while other specials are fireball invulnerable (hurricane kicks), and various other things like that.


If they’re the same it trades. Everying else depends on the positioning of the hitboxes.


Depending on the game, there may be an actual priority system in place where some attacks do auto lose to others (uncommon), but typically, its just hitboxes.


There are two basic types of hitboxes involved here. the character’s attackable hitbox (usually blue), and the characters attack hitbox (usually red). Both change depending on what you are doing. Quite simply, the red attack hitbox needs to overlap the blue attackable hitbox. Crouching lowers your hitbox, which is why you always want to be in a crouching position before you AA your opponent with a DP; their attack has to reach lower to hit you, making them get closer to the ground, giving your AA as much invincibility frames as needed to beat them out clean, no matter how good a priority their jump in attack has. It’s the same exact thing Akuma players do when they cancel cr.mk or cr.hk into ultra as an AA; the ultra RD has invulnerability frames so it can be used as an AA.