Overdrive (オーバーライズ) is an ability introduced in Trails of Cold Steel II. A small, red icon at the upper right corner of the screen gradually fills as actions are performed in battle. Once filled, two linked characters can go into Overdrive for three turns, which restores HP, EP, and CP, clears all status abnormalities, causes all attacks to unbalance enemies and allows all Arts to be cast instantly.
The Overdrive ability can be unlocked by passing the trials offered by Trial Chests scattered across Erebonia. The ability is unlocked only for the selection of characters who can participate in a Trial Chest.