Ability point

The ability point (AP) is the ability power measurement used internally by all games in the Splatoon series.

Primary abilities are worth ten points, and secondary abilities are worth three points. With there being a maximum of three primary abilities and nine secondary abilities, the maximum number of ability points a player can have is 57. Some abilities allow players to have higher ability points in theory, but in practice there is no additional effect because the games internally cap ability effects at 57 points.

Some abilities such as Opening Gambit can contribute points to multiple pools of ability points.

History
The ability point has behaved consistently between each game in the Splatoon series.

To date, no Splatoon game has quantified the worth of the large and small ability slots, leaving players to find out for themselves how much each slot type increases their ability point stat.

Examples
Player A equips three secondary slots of Swim Speed Up. Player B equips one primary slot of Swim Speed Up. This results in Player A having nine points and Player B having 10 points. Even though Player A has more Swim Speed Up abilities, the underlying point total means that Player B will swim slightly faster.