Armor Penetration
Armor Penetration is a property of a weapon or other attack which allows the attack to bypass Damage Reduction and Hardness. Both of those defenses are reduced by the attack's Armor Penetration before applying damage.
Example:
- Olaf the Orc is wearing thick armor, granting him DR 10.
- Randy the Ranger hits him with an arrow for 12 damage. The arrow has Armor Penetration 2, so the effective DR is only 8; the final damage is 4.
- Frank the Fighter hits Olaf with a sword for 15 damage. The sword has Armor Penetration 10, so the effective DR is 0. The attack inflicts 15 damage.