Berserk is a status in Final Fantasy IV. A target under this status will be uncontrollable, and will always issue an attack when the ATB bar is filled. Upon being inflicted by the status, the ATB bar will be reset. The attack power of the target increases by 50%. In the Game Boy Advance version of the game, if a target has both Confuse and Berserk and if Confuse is removed, Berserk is also removed.
In addition, the Avenger puts the wearer under permanent Berserk. This can only be removed by Zeromus'sBlack Hole and when Zeromus shakes, in addition to if the wielder is inflicted and cured of Confuse.