Talk:Armor penetration/@comment-128.61.37.206-20121207184000

http://na.leagueoflegends.com/board/showthread.php?p=32171428#32171428

Xypherous:  "% Armor Reduction (Step 2) and % Armor Penetration (Step 3) happen back to back. And they're both % effects so they stack multiplicatively with each other."

So the order of Penetration might be wrong.