D12

D12 is an unlockable activated item added in The Binding of Isaac: Afterbirth.

Effect

Re-rolls Rocks and Metal Blocks in the current room into Poops, other Metal Blocks, other Rocks, and/or TNT.
- Poops of any type and TNT cannot be re-rolled, although other obstacles may be rerolled into them.
- Also re-rolls Poops, Spikes, Fire Places, both types of TNT, Cobwebs, and Pillars.

Notes

Can be used to net more of a certain desired obstacle for interactions, such as more poops making Petrified Poop more effective or more rocks to farm Coins with Lucky Rock.
Chapter-specific obstacles (Urns, Mushrooms, Skulls, and Polyps) can be re-rolled. Depending on the current Chapter, rocks can also be re-rolled into them.
Rainbow Poop, Golden Poop, and Tinted Rocks are much less likely to be created by the D12 than all other obstacles.
Destroyed obstacles will not be rerolled.
While TNT can be created by the D12, Movable TNT cannot be.
The D12 will not re-roll Key Blocks or Fire Places.
It won't re-roll Stone Grimaces or other enemies.
This item can rarely reroll obstacles into Reward Plates, Killswitches, and very rarely into Crawl Spaces or trapdoors to the next floor.
It is possible to reroll the spikes in a Sacrifice Room and render the room unusable.
- Newly created spikes (but not retractable spikes) in Sacrifice Rooms use separate reward counters, allowing you to get more rewards in one room.
The D12 will not re-roll Pressure Plates, Marked Skulls, Dirt Patches, Teleporters, White Fire Places, or Bomb Rocks.
These obstacles will only reroll into another one in this group: Poops, Retractable Spikes, Normal and Red Fire Places, both types of TNT, and Cobwebs.
- These obstacles can also reroll into Reward Plates and Killswitches, but will not reroll any further.

Synergies

Car Battery: Re-rolls twice instantly, greatly increasing the chance of spawning Pressure Plates, Reward Plates, Killswitches and Crawlspaces.
Book of Virtues: Spawns blue die wisps on the middle ring. Wisps' tears have a 5% chance to reroll obstacles they hit. Poops and TNT barrels cannot be rerolled.
XVI - The Tower? / A Card Against Humanity: Created obstacles can be rerolled into more useful objects such as fire and Red Poop to damage enemies, or Red Buttons to instantly clear rooms/bosses.

Interactions

Car Battery: Re-rolls twice instantly without any benefits.

In-game Footage

Gallery

Splash image which appears when D12 is activated.

Trivia

The D12 is the only way in the game to remove metal blocks.
- Metal blocks can also be destroyed with Mega Mush.
The original Antibirth mod had its own D12 that functioned similarly to this item. For obvious reasons, that item wasn't added in Repentance, although the D12's effect was updated in V1.7.8 to be more similar to the Antibirth version.

Bugs

Bug!	Using D12 while Tainted Forgotten is sitting over a pit (not being thrown) will make his head and weapon disappear, rendering him unable to attack and preventing Tainted Soul from picking him up, unless the room is left or the run is exited and resumed. This can easily cause a soft-lock.

Bug!

If creates a

Reward Plate in the boss room on the floor where an alt door is allowed to appear (After

A Secret Exit is unlocked), activating the button to create enemies and kill will create another one, up to 4 doors (depending on the size of the room). Exiting the boss room will leave only the original alt door. By entering a copy of the door, you can go to the alt floor and if you exit, the original door will also be open, even if you did not open it.

Bug!

When rerolling obstacles while Isaac has ; any

Movable TNT or Fire Places spawned in the fear radius has a chance of being spawned momentarily feared with only the purple tint to indicate the status effect. This effect lasts even on the remains of either object after it's destroyed before the fear effect ends. Corn poops created in the radius are unaffected however the