Talk:Armor/@comment-5139296-20120527004849/@comment-119.131.217.20-20120727102025

Note: With Penetration Ar/Mr is never reduced. Its just ignored/substituted for the calculation. Other incoming damage without the attribute of Penetration will not receive the bonus.

Example: Target have 10 armor, you have 15 armor penetration, you deal true damage to target. But if your ally attacks the target without any armor penetration, the target will be seen as still having 10 armor.

Think about it as penetration go through the shield and deals damage while reduction destroys the shield.