So they renamed it to lethality and made it scale with enemy level. Lethality is armor pen. You get less armor pen depending on the level of the person you are attacking. If they are low level, you get less arpen, if they are level 18, you get the max value of your lethality stat as armor pen. http://i.imgur.com/1AA5AFY.gif. http://i.imgur.com/sNW9yoI.jpg.