Binding of Isaac: Rebirth Wiki
Binding of Isaac: Rebirth Wiki

Added in Afterbirth †

D1 is an unlockable activated item added in The Binding of Isaac: Afterbirth †.



  • By dropping a card, rune, or pill in a room with no other pickups, then using D1, this item can function similarly to Blank Card Blank Card, Placebo Placebo, and Added in RepentanceClear Rune Clear Rune.
  • Rune of Jera Rune of Jera can not be duplicated.
  • Mimic Chests will not be duplicated.
  • A normal Chest may be duplicated into a Red Chest or a Mimic Chest.
  • Opened chests will be duplicated into an unopened copy.
  • Removed in Repentance A duplicated trinket is mostly useless, as you cannot pick up two of the same trinket even with Mom's Purse Mom's Purse, Belly Button Belly Button, or Smelter Smelter.
  • It is possible to duplicate Shop Shop pickups that have not been purchased yet.
  • With Car Battery Car Battery, it is possible to infinitely generate Lil' Batteries from a single Lil' Battery.
  • In combination with a 48 Hour Energy pill and Paper Clip Paper Clip, the initial Locked Chests on Chest Chest can be infinitely duplicated and opened.
  • In Greed Mode, if a Lil' Battery appears in the Shop Shop and a 2 of Diamonds 2 of Diamonds is acquired, infinite money can be gained by duplicating the Two of Diamonds.
  • Added in Repentance With a ? Card ? Card and Schoolbag Schoolbag, single use items can be used an unlimited number of times by duplicating the card.


  • Added in RepentanceBook of Virtues Book of Virtues: Spawns two white six-sided die wisps, on the middle ring, at the same time. An extra wisp spawns if no pickups are duplicated.

In-game Footage[]


  • D1 is the only die item that doesn't re-roll anything.
    • As such, its description, in certain cases, can be ironic, as the outcome is entirely predictable if there's only one pickup. This makes sense because the die only has one pip on each of its 6 sides.
    • As an exception, Added in RepentanceSpindown Dice Spindown Dice, although it technically does re-roll items, has a controlled and consistent result.
  • D1 is the only standard die item that doesn't have the respective number of sides as outcomes, but rather, just a D6 with all sides having singular pips. Rather, an actual D1 would be more accurately pictured as a Mobius strip or a sphere.


PC Normal and hard modes only 34HF 9E4F (Treasure Room adjacent to spawn)