Pachi-Slot God Eater loosely follows the premise and story of the original God Eater: As the protagonist (of either gender), you come to the Fenrir Far East Branch, take the God Arc compatibility exam, and fight against Aragami.
Story scenes play out in between battles. Gameplay consists of two segments: enemy selection and battle. During enemy selection, your slot roll combined with a scrolling cursor on the screen determines which Aragami you fight. During battle, three numbers appear on the top screen below you and/or the Aragami. Lining up slot symbols beneath each number results in the protagonist attacking the Aragami.