The Party Gauge is a battle mechanic in Xenoblade Chronicles. It is a blue three-bar gauge displayed on the left and top of the screen. A full bar is necessary to revive an incapacitated member. The full gauge is necessary to initiate a Chain Attack.
The Party Gauge is filled during battles whenever a "B" prompt is successful. It can be also filled by using some arts, a special support or ether art such as Happy Happy, a successful side or back hit physical art such as Slit Edge or Back Slash. Simple Auto Attacks of a member if its Tension is high will fill the Party Gauge step by step. Defeating an enemy during a Chain Attack fills the Party Gauge by one bar. Landing a Critical Hit increases the Party Gauge slightly.
When not in battle, the Party Gauge will slowly deplete. This effect can be lessened through the "Mind of the Warrior" Skill granted by Dunban's Prudence Skill Tree. Loading the game will completely deplete the Party Gauge.