The Binding of Isaac is a 2D Action-Adventure in which the player controls Isaac or one of five other unlockable characters as they explore the dungeons located in his mother's basement. The player must explore the trap- and monster-filled rooms and defeat the boss on each floor in order to delve deeper. Powerups can be found along the way, granting the player various abilities and boosts to help him survive. Monsters and items never respawn as soon as a room is cleared, so the player has a limited pool of resources to work with and careless mistakes can be costly. The rooms and the powers made available to the player are randomized each game, allowing for considerable replay value.
When Isaac’s mother starts hearing the voice of God demanding a sacrifice be made to prove her faith, Isaac escapes into the basement facing droves of deranged enemies, lost brothers and sisters, his fears, and eventually his mother.