Publication:Grim-N-Gritty/Appendix 5/Armor Piercing Weapon

This spell makes a weapon magically armor piercing. Only one-half of an opponent’s Protection applies against the damage of the weapon.

If cast on projectiles, such as arrows, sling stones, or crossbow bolts, the armor piercing effect on a particular projectile ends after one use, whether or not the missile strikes its intended target. (Treat shuriken as arrows, rather than as thrown weapons, for the purpose of this spell.)

You cannot cast this spell on a natural weapon, such as a claw.

Note: This spell replaces keen edge.