Bone Spurs is a passive item added in The Binding of Isaac: Repentance.
- Enemies spawn 1-2 floating bones on death, which block enemy shots and damage/repel enemies that touch them.
- Bones block 2 shots and/or deals 2 ticks of damage before breaking.
- Bones deal contact damage equal to Isaac's damage in the moment they were created.
- This means that if the damage stat was changed, the bones that were already present on the screen will use Isaac's old damage stat.
- BFFS!: Doubles the bones' size and damage.
- Spin to Win: Boosts the bones' damage while spinning even though there's no visual tell of the effect.
- A bone spur is a bony growth that often occurs close to joints and can have a multitude of causes from joint damage from osteoarthritis to excessive overuse of said joints.