Port priority

A Wii with its Gamecube controller ports exposed. Note the sets of small dots beneath each slot that represent P1, P2, P3 and P4 from left to right.

Port priority (also known as controller slot priority) is a set of rules that determine the outcome of certain situations between characters, during matches. These rules are based on the numbered player ports (slots) in which each player plugs in, or occupies with his or her controller, and these are represented by P1, P2, P3 and P4 with respect to the first, second, third and fourth ports. CPU players may also occupy these ports, and are affected by port priority in the same ways as human players.

In the Super Smash Bros. games, the outcome of certain concurrent events, such as two characters being KOd or attempting to grab each other simultaneously, are determined by port priority. For unknown reasons, in Brawl, port priority also influences the outcome of situations in which two characters are attacked during a grab, through an effect known as Faux Super Armour.

Concurrent events

During gameplay, certain events may occur at the same time, that is, on exactly the same frame. While the result of simultaneous attacks is resolved through the laws of attack priority, the outcome of other concurrent events, such as two characters attempting to pick the same item up, are determined by port priority. It should be noted that the probability of two such events occurring on the same frame is extremely low, since one frame is equal to 1/60th of a second.

Grabbing

In Melee, if two opponents attempt to grab each other, and both grab hitboxes connect at the same time, only one player will end up grabbing the other, since two players cannot be grabbing and grabbed at the same time. The above also applies to two players' simultaneous use of Mewtwo's Confusion in Melee. Port priority determines that the player with the lowest port, that is, closest to P1, is awarded with the grab. Essentially, this means that P1 is always awarded with the grab, and P4 is never awarded with it. In this case, P1 > P2 > P3 > P4.

Two characters attacking a third

In Melee, if two characters attack a third, and both attack hitboxes are within priority range and connect with this character at the same time, the trajectory of the third character's knockback will only be affected by a single attack, not both. The third character will be projected by the knockback of the attack from the player with the lowest port, closest to P1. Note that regardless of their trajectory, the third character will still take damage from both attacks.

Picking items up

In Melee, if two or more characters attempt to pick the same item up from the ground at the same time, only one character will acquire the item. Under these conditions, the player with the lowest port, closest to P1, will acquire the item. Note that different characters pick items up at different speeds.

Landing in the same space

In Melee, if two or more airborne characters attempt to land in the exact same place on the ground, some characters may be pushed left or right upon landing. This is because two characters may not occupy the same space while standing on the ground. The players with the lower ports, closer to P1, always get pushed to the left.

Transformations

In Brawl, if two players attempt either to transform between Sheik and Zelda, or switch between the Pokémon Trainer's Pokémon at the same time, one player will complete his or her transformation first. The player with the lowest port, closest to P1, always finishes their transformation before the other player. This issue is reportedly caused by the fact that Brawl loads these characters during gameplay, as opposed to before matches begin, and the Wii may not have enough memory to load two or more characters simultaneously.

KOs

Port priority determines the winner in certain cases of simultaneous KOs, including those that involve the use of suicide techniques. In this field, its influence in Melee differs from that in Brawl. In Melee, the outcome of simultaneous KOs during normal stock matches is not determined by port priority, regardless of their causes. However, when a match involving two players is tied and Sudden Death is initiated, if both players are KOd at the same time, the player with the lowest port, closest to P1, wins the match. In this case, P1 > P2 > P3 > P4.

Unlike Melee, the winner of a simultaneous KO during a Sudden Death match in Brawl is random, and unaffected by port priority. However, in the NTSC and NTSC-J versions of Brawl, it does affect the use of Bowser's Flying Slam as a sacrificial KO technique. If, during a stock match involving two players, Bowser uses Flying Slam to sacrificial KO on both players' last stocks, Bowser will either win or a Sudden Death match will be initiated. In this scenario, if the Bowser player's port is lower (closer to P1) than that of his or her opponent's port, the Bowser player wins the match. However, if the Bowser player's port is higher (closer to P4), Sudden Death initiates. In the PAL version of Brawl, the use of Flying Slam in the aforementioned manner will win Bowser the match regardless. Should Sudden Death be initiated for any reason after a match, if a Bowser player uses Flying Slam to end the Sudden Death match, all versions of Brawl will declare him or her the winner, irrespective of port positions.

Faux Super Armor

Faux Super Armor (abbreviated to FSA) is an effect in Brawl that protects one player from the knockback and status ailments of external hazards and third party attacks during a grab, regardless of which character has grabbed the other. Players with FSA still take damage from interrupting attacks, and will undergo a grab release animation if their opponent is knocked, but will not otherwise be affected. Port priority determines that the player with the highest port, closest to P4, receives FSA during a grab. In this case, P4 > P3 > P2 > P1.

Examples:

• Falco (P2) grabs Ike (P3) and while Falco is holding Ike, another player, Lucas, attacks them with PK Freeze. Since Ike (P3) has a higher port than Falco (P2), Ike receives FSA, so he is released and takes damage from Lucas' attack, but is otherwise unaffected. Falco, however, will take damage as well as being knocked into the air and becoming frozen.
• Toon Link (P1) pulls out and holds a bomb. Lucario (P4) grabs him, and while he is holding Toon Link, the bomb explodes. Lucario (P4) receives FSA and only takes damage, but Toon Link (P1) incurs knockback and a fire ailment from the bomb.
• Snake sticks a C4 onto Meta Knight (P2). Meta Knight then grabs Diddy Kong (P1), and uses his up throw. This causes both he and Diddy to rise above the stage, and while they are high in the air, Snake detonates the C4. Since Meta Knight has FSA, he falls to safety while Diddy is KOd by the upper blastline, from the C4's knockback. This trick, known as the "Omnigay" (named after a player called InfernoOmni), is popular in competitive team matches.

Due to the effects of FSA, port priority is of significant importance during competitive doubles matches, and singles matches that involve Snake, Link or Toon Link, since these characters can summon explosive items. Faux super armor can be used to advantage as well using Pikachu's Thunder or any characters mentioned above (P1) and Kirby/Meta Knight's up throw (P4) for quick vertical KOs. Consequently, many tournaments enforce rules and procedures to ensure fairness. For example, before a set of singles matches, a game of rock-paper-scissors may determine which player chooses his or her port first if there is a dispute, or the privilege may instead be given to the player who strikes the first stage in a stage striking process. Doubles sets often arrange team players in a "1221" fashion, and may allow the losing team to choose their ports for the second match.

While ditto matches - character matchups involving two of the same character - are normally regarded as even for both players, the impact of FSA is significant enough to create slight imbalances in some of Brawl's ditto matchups. This imbalance is most strongly pronounced in the Snake ditto, where the outcome of grabs and throws can be an important part of gameplay. As a result of FSA's effects, Snake is considered the only character to have an uneven matchup when fighting against himself; the Snake player using the higher port is considered to have a slight advantage.