You're trapped with a demon in a room with no way out—your only chance to survive? Beat him at Black Jack. Oni Jack is a blackjack roguelike where traditional rules don't apply. Use mystical relics to alter your plays, trick your evil opponent, or save yourself from certain death. Plus, purchase upgrades for these relics to boost their effects and go further in the misterious gauntlet; survive the cursed rounds that change the game’s rules; defeat the various bosses who use cursed powers to their advantage; and ultimately defeat the evil Oni at his own game. Will you bet your soul in this PS2-style nightmare?