D1

	5.100.476
	4 rooms
	Defeat Ultra Greedier as Isaac

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

Effect[edit | edit source]

Duplicates 1 random pickup in the current room, including cards, runes, chests, and trinkets.

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 and Placebo.
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.
A duplicated trinket is mostly useless, as you cannot pick up two of the same trinket even with Mom's Purse/ Belly Button or Smelter.
- However, with "consumable" trinkets such as Store Credit or Bag Lunch, it can be extremely powerful.
It is possible to duplicate shop pickups that have not been purchased yet.
With Car Battery, it is possible to infinitely generate Lil' Batteries from a single Lil' Battery.
In combination with a 48 Hour Energy and Paper Clip, the initial Locked Chests on The Chest can be infinitely duplicated and opened.
In Greed mode, if a Lil' Battery appears in the Shop and a 2 of Diamonds is acquired, infinite money can be gained by duplicating the Two of Diamonds.

D1 is the only dice 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 dice only has one pip on each of its 6 sides.

PC 34HF 9E4F (Treasure Room adjacent to spawn)

Dice

D1	D4	The D6	D7	D8	D10	D12	D20	D100	D Infinity
Pickups (Duplicates)	Isaac's Items	Room's Items	Room	Stats	Enemies	Rocks	Pickups (Randomizes)	Items Pickups	Random Dice

Isaac Unlocks