Armor penetration
From Guild Wars Wiki
Armor Penetration (often abbreviated as AP) is the amount of armor that an attack or spell ignores when calculating damage.
For example, an Air Magic spell that grants 25% armor penetration would deal more damage to a target than a similar spell with the same numerical damage, but no penetration. If the targetted foe has 100 armor, when the spell strikes, it will treat the target as having 75 armor instead. This would cause approximately ~54% more damage to the target than otherwise.
There are two different types of armor penetration: base armor penetration and bonus armor penetration.
[edit] Base armor penetration
Base armor penetration is a set amount of armor penetration, such as "This attack has 20% armor penetration." If there is more than one source for base armor penetration, the largest value is used; base armor penetration does not stack.
- Strength grants 1% AP per rank when using attack skills.
- Penetrating Blow and Penetrating Chop grant 20% AP when using them.
- Penetrating Attack and Sundering Attack grant 10% AP when using them.
- Primal Rage grants 20% AP.
- Many Air Magic spells have 25% AP.
- Destructive Was Glaive grants 10% AP for 10 seconds while holding her ashes.
[edit] Bonus armor penetration
Bonus armor penetration is an additional amount of armor penetration, such as "Armor penetration 20%." These do stack and add to the largest base armor penetration.
- Sundering weapon upgrades have a 10-20% chance to give attacks an additional 20% AP.
- Hornbows give an additional 10% AP to their attacks.
- Judge's Insight gives an additional 20% to attacks.
- The blessing Warrior's Might grants an additional 10% AP to attacks.

