Special gauge

The special gauge is an indicator during a battle of how close a player is to activating their special weapon. When the indicator is full, a noise will be heard, the gauge will show a prompt, and the head of the player will begin to sparkle, indicating that they can use their special by pressing. The special gauge can be filled up by inking turf, having control over the objective in Ranked Battle, helping charge a teammate's Booyah Bomb, and (if the player's current headgear has Tenacity as a main ability) having not as many team members alive as the enemy team; the latter three fill up the gauge a lot slower than inking turf.

Description
The special gauge fills up in a clockwise fashion with the player's current ink color. It can be used by pressing when full. During use, it depletes counter-clockwise until empty. Some special weapons instantly depletes the entire gauge, such as the Killer Wail depleting slowly upon aiming and instantly depletes upon firing.

Splatoon
Each special weapon require a specific amount of turf painted to charge regardless of main weapons.

Prior to version, when a player was splatted before the special gauge was depleted, the player would respawn with half of the remaining gauge filled (barring the use of Special Saver-equipped gear). With version 2.7.0, all main weapons fall into one of three special depletion classes: light, medium, and heavy. Light-class weapons lose 40% of the special gauge when the player is splatted, medium-class weapons lose 60%, and heavy-class weapons lose 75%.

A table showing the depletion class of all weapons can be found at the list of special weapon sets in Splatoon.

The gauge also shows the player's primary abilities below it.

Splatoon 2
In this game, the gauge also shows the current sub weapon on its top left corner, but no longer shows the player's primary abilities.

The required amount of turf painted now depends on the main weapon rather than the special weapon. For example, despite both weapons having the Tenta Missiles as their special, the Bamboozler 14 Mk I needs 200 points to charge, while Splat Dualies only need 180 points to charge.

Without abilities, players lose 50% of their remaining special gauge after being splatted regardless of their main or special weapon. If a player is splatted while executing a Splashdown, only 25% of their remaining special gauge is lost.

Single-player
The special gauge is not activated in Octo Valley, Octo Canyon, the Octo Expansion, or the Battle Dojo. Instead, the player must collect their special weapons from cans.

Turf Wars and Ranked Battles
In multiplayer Turf Wars and Ranked Battles, as well as in the Shooting Range, the player's special gauge fills as they cover turf in ink. The turf must be turf that would normally earn the player points in Turf War, such as the floor. When the player is splatted, their special gauge will be partially depleted upon respawn.

Salmon Run
In Salmon Run, each player start the run with two charges of a special weapon (represented by two silver pack icons on the gauge's top left corner, replacing the sub weapon icon) across the entire run. The gauge cannot be refilled under all circumstances. When the special is not in use, the gauge itself is always full when the player has remaining charges and is empty when they have no charges left. On use, one silver pack icon is removed and the gauge shows the remaining duration of the current charge like in other modes.

The gauge is confirmed to reappear in Salmon Run Next Wave and presumably functions exactly the same as it was in Salmon Run.

Abilities
Abilities on a player's gear can affect the special gauge: