Talk:Armor penetration/@comment-5120256-20121211000616/@comment-70.248.198.1-20121214123811

A maximum of 100% is the highest you can reach when reducing armor by %. After that you would need flat armor penetration to go any further, however, at 0 armor you're doing true damage to the target, not in the sense of Vayne's passive, but in the sense that if you have 100 attack, you will deal a true 100 damage to their life points per hit.

In regards to his 25% Apprehend, a Last Whisper giving 35%, and two Black Cleavers also at 25% would give him 115% armor reduction to any target, but would ignore the last 15%, since 15% of 0 is still 0.