Talk:Anivia The Cryophoenix/@comment-4030326-20110610010121/@comment-2124153-20110610020931

Goes in this order: %magic reduction, flat magic resist reduction, flat magic penetration, %magic penetration. So the flat pen goes first, and then the %reduction goes last. That usually doesn't leave a lot of resistance to lower, which is why people don't usually recommend items like Void Staff unless the target has a lot of MR, like 100+.

It used to be the other way around, but that was kinda overpowered and had no real downside. Now it's just situationally useful to get %pen.