In-game pickup line
“Bleed me dry”
Mechanics
What Blood Oath does
- On entering a new floor, the familiar drains most of Isaac's Red Hearts.
- The health lost determines a damage and speed bonus for that floor; each half-heart drained can also trigger on-hit effects.
In a run
Practical note
Plan healing around the floor transition so the health cost does not catch you unprepared.
Reference
Game data and sources
The item ID, quality and pool listings, icon, game-file tags, and short pickup line come from the extracted Repentance files. This effect explanation is an editorial summary checked against the references below. Repentance+ can differ.
