IV - The Emperor
CardRebirthUnlocked
How do you unlock IV - The Emperor?
Verified starting unlockSource data confirms that no unlock is required.
Teleports Isaac into the Boss Room.
Available from the start
No unlock needed — this is available in every new save file.
What unlocking IV - The Emperor leads to
Nothing depends on this yet.
Source: bindingofisaacrebirth.wiki.gg
Imported 2026-09-13