Grindstone is a consumable in Shotgun King Cards, a mod for The Binding of Isaac.

While held Each cleared room makes card stronger by +0.1 damage.

On use 3.0 + AccumulatedDamage fading damage up.

The following special synergies and interactions for Grindstone have been documented.

* Note that not all possible synergies and interactions are listed here.

• Download Shotgun King Cards from the Steam Workshop.