Dark Prince's Crown is an unlockable passive item added in The Binding of Isaac: Afterbirth †.
- When at exactly 1 Red Heart, some of Isaac's stats are increased.
- The effect is lost any time Isaac gains or loses Red Hearts.
- The crown will glow red while active; if inactive, it will appear black.
- Full Bone Heart containers are counted towards the maximum.
- This item pairs well with Eve, since she starts with Whore of Babylon, and is the only character that can gain Whore of Babylon's effect at 1 heart.
- This item does not affect ???, The Lost, The Soul, Dark Judas, Tainted Judas, Tainted ???, Tainted Lost, Tainted Soul, or Tainted Bethany since they cannot gain Red Hearts.
- This item only affects Keeper and Tainted Keeper when he has only one Coin Heart.
- This item only affects The Forgotten when he has one full Bone Heart.
- The effect does not stack with multiple Dark Prince's Crowns.
- This item is the first Afterbirth+ item by ID number.
- This is the demonic counterpart of the Crown of Light.