Binding of Isaac: Rebirth Wiki

Added in Repentance

Red Key is an unlockable activated item added in The Binding of Isaac: Repentance.


  • Allows Isaac to create a Red Room Red Room by using it next to a wall where there would be no conditions that could prevent a room from spawning there (i.e., the same conditions for a Secret Room Secret Room to spawn). This is indicated by red door outlines on walls.
  • These rooms are most commonly normal rooms, but have a 10% chance[1] to be a special room instead, even including Red Devil Room Devil Rooms or Angel Room Angel Rooms.
    • Red special rooms of any kind can appear in every floor.
  • These rooms use a special Red Room icon on the map.


  • The types of special rooms that a Red Room Red Room can be are the following:
  • All rooms made by Red Key will be 1x1 rooms that can have doors available on all sides (same conditions as a Secret Room Secret Room / Super Secret Room Super Secret Room).
  • In Home Home, Isaac can create a "Red Room" on the left side of the map right under Mom's room. This room will actually be a closet containing a non-tainted character's Tainted form.
    • If the respective Tainted character has already been found or a Tainted character is played, the room will contain Inner Child Inner Child instead. If Inner Child has not been unlocked, the room will contain a Shopkeeper.
  • If a door created by Red Key takes Isaac outside of the 13x13 area of the floor, he will be taken to the I AM ERROR I AM ERROR room.
    • This does not occur in Corpse Corpse II, Dark Room Dark Room, Chest Chest, The Void The Void, or the special version of Mausoleum Mausoleum / Gehenna Gehenna II containing Dad's Note Dad's Note. No door outlines will appear at any boundary walls.
    • The I AM ERROR room door can only be created while already inside a Red Room. Normal rooms will not show the red outline if they are at the map's boundary.
  • Red Shop Shops will regularly not offer items from the Shop item pool for sale, but instead draw from Boss and Treasure Room pools instead. Additionally, Red Shops have a chance to become advanced Shops with many more items for sale, akin to Tainted Keeper Tainted Keeper's better Shops.
  • Red Key can't overwrite Secret Room Secret Rooms or Super Secret Room Super Secret Rooms. This can be used to discern their locations by finding walls that don't have red door outlines that would otherwise be valid Red Room spots.
  • Red Key can't create a room adjacent to the Boss Room Boss Room on most floors, with some exceptions:
    • Red Key can create a room adjacent to Hush's room in the top right where the room that leads to The Void The Void usually generates. The door to this looks like a crack. This Red Room can only be created when Isaac is in another Red Room adjacent to it, i.e. from branching off one of the Treasure Room Treasure Room.
      • Isaac can enter Hush's room from this crack, but going the other direction will lead him to the Entrance Portal room.
      • Strangely, Isaac also can't create Red Rooms adjacent to the Shop Shop on this floor either.
    • Red Key can create rooms adjacent to most Boss Rooms in The Void The Void, including Delirium's room. This can be used to find a Boss Room door leading to what would be an empty space (though this may find Mr. Fred instead).
    • Red Key can create rooms adjacent to the Boss Room Boss Room in the Mirrored World of Downpour Downpour / Dross Dross II.
    • Red Key can create rooms adjacent to the Boss Room Boss Room during Ascent.
  • When Isaac enters any Red Room adjacent to the Ultra Secret Room Ultra Secret Room, it immediately appears on the map along with the Secret Room jingle, and its door will automatically open.
  • If Isaac encounters a Red special room, all of its doors will be its special theme doors.
    • All doors in a Red Curse Room Curse Room still feature spikes, which will damage Isaac if he decides to enter/exit.
    • A Red Vault Vault's doors or a Red Dice Room Dice Room's doors each require two keys to open. The door where Isaac uses Red Key will be automatically unlocked, but the other doors remain locked until Isaac goes through them from inside or unlocks them from outside.
  • Multiple Red special rooms of the same type can spawn on one floor.
  • All Red Sacrifice Room Sacrifice Rooms will have their own independent use counters and rewards.
  • If Isaac has a teleport to a specific room (XVII - The Stars XVII - The Stars, IX - The Hermit IX - The Hermit, Teleport 2.0 Teleport 2.0, etc.) and has created a special room such that there are multiple of a certain type on one floor, the teleport will choose randomly between each room.
  • It is possible to obtain Knife Piece 1 Knife Piece 1 and Knife Piece 2 Knife Piece 2 outside of the intended methods by spawning Treasure Rooms that contain them.[citation needed]
    • Red Rooms in Downpour/Dross can contain White Fire Places as well.
  • Isaac is able to create Red Rooms in the Mirrored World of Downpour Downpour / Dross Dross II. They will be reflections of the original floor's Red Rooms, and special rooms created in this way will still be empty.
  • Red Rooms can't be created around the Mine Cart Room Mine Cart Room of Mines Mines / Ashpit Ashpit II.
    • Red Rooms on these floors can contain the yellow buttons used to build the mine cart track, however these ones do nothing.
  • Red Rooms in Chapter 3 can contain Marked Skulls even before the Ascent is unlocked.
  • When in Dark Room Dark Room or Chest Chest, their spawn room containing their respective chests can be created by Red Key. These will function as regular chests of their respective type.
    • New Mega Satan doors can't be found in these rooms.
  • Red Treasure Room Treasure Rooms will be present in the Ascent, and will not replace regular Treasure Room Treasure Rooms.
  • It is possible for red Sacrifice Room Sacrifice Rooms to appear in the Dark Room Dark Room, and it's possible to be teleported on the 12th sacrifice and beyond. If this happens, the new Dark Room will have the exact same room layout as the previous Dark Room, including red rooms, allowing the player to infinitely replay the floor.
  • If a red Sacrifice Room Sacrifice Room appears in The Void The Void, then it is possible to defeat The Lamb The Lamb after taking the path through Chest Chest. This makes it possible to get up to 8 Completion Marks in the same run if playing quickly.



  • 4.5 Volt 4.5 Volt: Usually generates fewer than 1 charge per room, as Red Rooms are always 1x1.
  • Member Card Member Card: The trap door will always lead to the same special room as the regular Shop Shop.
  • Void Void: Won't acquire any of the Red Key's properties.
  • Car Battery Car Battery: No effect.

In-game Footage[]


  • This item is used in Red Redemption (Challenge #44).
  • In the Antibirth mod, this item used to be unlocked by defeating The Witness as Cain Cain.
  • During the Kickstarter campaign for The Binding of Isaac: Four Souls Requiem, the Red Key was revealed to be present in Repentance by developer Kilburn[2].
  • While Isaac is in a red room, the pitch of the music track currently playing is slightly distorted. This effect is reverted once Isaac leaves the room.


PC Hard mode only CL9P JM0R ( Eden Eden Starting Item)

PC Hard mode only B0H6 M13C (Curse Room Curse Room next to spawn)

PC Hard mode only 67DH 1KJ4 (Curse Room Curse Room next to spawn)

PC Hard mode only CC6W JJ3N (Curse Room Curse Room next to spawn)

PC Hard mode only J4TS SF13 (Curse Room Curse Room next to spawn)

Switch Hard mode only 17XF CWQH (Curse Room Curse Room next to spawn) AW2QYK0T Mode Hard Curse Room Next to the Spawn Xbox