D12

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.

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.
While TNT can be created by the D12, Movable TNT cannot be.
The D12 will not re-roll Key Blocks or Fire Places. It also won't re-roll (Stone Grimace) Stone Grimaces, or other enemies.
(Added in Repentance) The D12 will not re-roll Spiked Rocks, (Fool's Gold) Fool's Gold Rocks, Pillars, or Marked Skulls.

(Added in Repentance) 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.