A fighter ability, more often referred to as a passive ability, character mechanic, or character gimmick is an unofficial term used in fighting games, including the Super Smash Bros. series, that describes special mechanics specific to certain characters (and/or their clones). They can grant said fighter a passive ability, a chargeable meter, extra moves in their arsenal, an ammunition system, or other mechanics that are not directly linked to their moveset. In Super Smash Bros. Ultimate, many fighter abilities have a special icon on the character's damage meter.
List of single fighter abilities
Certain moves (such as Monado Arts, Wario Waft, or Wonderwing) are commonly associated as that character's "gimmick", and in some cases have special icons on a character's damage meter, above their head, or on their model, and may have a separate section detailing the move on the Move List, but because they do not grant the user extra moves and are directly linked to that specific move, they will not be listed. Some special moves have multiple variants mapped to its input, such as Burning Knuckle / Crack Shoot and Egg Firing / Breegull Blaster, but because this is a common occurrence even when said moves don't have multiple names, such as with Timber or Spin Attack, these instances will only be listed if they are either on a non-special move or are directly linked to another unique mechanic. Other commonly misconstrued "gimmicks" include common mechanics that don't extend outside of the moves themselves but are applied across a character's moveset consistently (such as Pichu's recoil or Marth's tipper), or do extend outside of a character's basic moveset but are merely just a common mechanic being amplified (such as Jigglypuff's self-sacrificial shield jump). Additionally, unique but purely aesthetic mechanics such as Steve's ability to look up and down by tilting the control stick or Pit and Mega Man's idle animations slightly changing depending on what move they used last, will not be listed either.
List of shared fighter abilities
In addition to the above, certain mechanics and abilities are present on multiple non-clone fighters, but are not universal throughout the roster.