Talk:Magic penetration/@comment-113.67.177.160-20120703020527/@comment-81.187.222.146-20120705092750

You are very wrong indeed. How can you say "i will have my damg increased" and then say you do only 0.9x damage? You can't even know what your damage increase will be unless you know what your target's mres was in the first place.

It's 0.90 (mastery) x 0.60 (void staff) = 0.54 = 46% penetration. If the target had (being lazy here) exactly 100 mres, you ignore 46 points of it. Given that 100 mres is a 50% reduction, and 54 mres is a 35% reduction, that's about a 1.4x damage increase.