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Polished Bone

AchievementRepentanceUnlock unknown

Achievement details

Achievement number: 576
Description: ???
Requirement: Defeat Isaac, ???, Satan, and The Lamb as Tainted Forgotten

How do you unlock Polished Bone?

In The Binding of Isaac, Polished Bone is unlocked by earning every normal-mode completion mark as Tainted Forgotten.

Structured pathSource-backed requirements are mapped into trackable steps.

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See the full unlock path for Polished Bone — 6 steps

All of
- Tainted Forgotten → Isaac (normal)
  - Tainted Forgotten
- Tainted Forgotten → ??? (normal)
  - Tainted Forgotten
- Tainted Forgotten → Satan (normal)
  - Tainted Forgotten
- Tainted Forgotten → The Lamb (normal)
  1. Defeat Satan 5 times to unlock The Negative. source
  2. The Negative is a guaranteed drop from Mom; take it, then defeat Satan in Sheol and touch the chest to enter Dark Room. source
  3. Find and defeat The Lamb in Dark Room. source
  - Tainted Forgotten

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What unlocking Polished Bone leads to

Source: bindingofisaacrebirth.wiki.gg

Imported 2026-09-13