Binding of Isaac: Rebirth Wiki


Boss Rooms contain one of the many bosses, with victory granting Isaac an item from the Boss pool, hearts (depending on difficulty), and a trap door leading to the next level.

Notes[ | ]

  • Double Trouble Boss Rooms contain 2 bosses of the same type from the previous chapter. Defeating them only gives one item. Double Trouble Boss Rooms only appear from chapter 2 onward.
    • (except in Rebirth) Double Trouble Boss Rooms can now contain 2 bosses of different types. Additionally, they can appear as early as chapter 1.
  • If the floor is affected by Curse of the Labyrinth, 2 separate Boss Rooms will appear in series. The trapdoor to the next floor will only appear after defeating the second boss.
  • When a boss is defeated, an entrance to a Devil RoomDevil Room or Angel RoomAngel Room can appear.
    • A Devil Room door can't appear on the first floor, unless JokerJoker is used. A Devil Room door can also appear in a boss room on the first floor if the floor is spawned with the Curse of the Labyrinth, in which the Devil Room door will appear after defeating the second boss.
    • Upon defeating Boss Mom's Heart ingameMom's Heart, a Devil RoomDevil Room containing a trapdoor or an Angel RoomAngel Room containing a beam of light may appear. This allows Isaac to visit SheolSheol or CathedralCathedral respectively even if Boss It Lives ingameIt Lives has not yet been unlocked. If one of these paths is taken instead of touching the large chest, the next Mom's Heart ending will not play but will be unlocked and it will count as a victory against Mom's Heart.
      • (except in Rebirth) Devil RoomDevil Rooms and Angel RoomAngel Rooms no longer contain a trapdoor or a beam after defeating It Lives. They instead have their normal contents.
  • Boss Mr. Fred ingameMr. Fred, (in Repentance) Boss Tuff Twins ingameTuff Twins, (in Repentance) Boss Great Gideon ingameGreat Gideon, (in Repentance) Boss The Shell ingameThe Shell, and Mega Satan Head ingameMega Satan are always fought in a double-sized (2x1) room.
    • (except in Rebirth) Boss Hush ingameHush is always fought in a 2x2 room and Boss Ultra Greed ingameUltra Greed is fought in a double-sized one.
    • (in Afterbirth † and Repentance) Boss Delirium ingameDelirium is fought in a 2x2 room.
    • (in Repentance) Boss Mother secondphase ingameMother is a fought in a regular room in her first phase, which expands to a double-sized room for her second.
  • Before the boss has been defeated, the eyes of the skull above the boss room's door are flashing.