Duality

From The Binding of Isaac: Rebirth Wiki
Jump to navigation Jump to search
(except in Rebirth and Afterbirth)

Duality is an unlockable passive item added in The Binding of Isaac: Afterbirth †.

Effects

  • Whenever a Devil RoomDevil Room/Angel RoomAngel Room spawns after defeating a boss, the other will also spawn.
    • Upon entering one, the other one will disappear.
    • Both rooms will spawn even if a devil deal was made before.
    • In rooms without enough accessible walls, only one of the two will spawn.

Notes

  • Even with Collectible Goat Head icon.pngGoat Head or Collectible Eucharist icon.pngEucharist, both rooms will not stay open, and entering either of the rooms will make the other disappear.
  • Teleportation via a JokerJoker card, a Red Chest.pngRed Chest, or a Sacrifice RoomSacrifice Room before defeating the boss and choosing a door will follow the normal rules of Devil/Angel Room generation, instead of a 50/50 chance.
    • This means that if Duality was taken as a Devil deal, or any other deal with the Devil was made in the run, teleportation will always lead to the Devil RoomDevil Room.
    • The room that was chosen this way will be the only one that opens once the boss is defeated.
    • Teleporting after choosing a door will always take you to the same room.
    • Gaining Duality during Greed/Greedier Mode will only generate one room as per normal, rendering it normally useless. However, both rooms will generate in the penultimate floor, The Shop.

Synergies

Interactions

  • Character Tainted Lazarus icon.pngTainted Lazarus: The Lazarus that fights the boss must be the one holding Duality in order for it to trigger.

In-game Footage

Trivia

  • Duality is one of only five items to appear in both the Angel and Devil item pools, the others being Collectible 7 Seals icon.png7 Seals, Collectible Lil Delirium icon.pngLil Delirium, Collectible Void icon.pngVoid, and (in Repentance and Repentance+)Collectible Purgatory icon.pngPurgatory.
  • The Duality image appears to be similar in concept to the yin and yang symbol of Ancient Chinese philosophy, as the latter represents the concept of dualism as well. However, they don't quite appear to be exact in terms of the diameter format.