Talk:Magic penetration/@comment-142.68.158.126-20120323222051/@comment-4087140-20120324073443

Most melee non-tank champions naturally increase to like 55 MR by level 18; everyone else naturally stays at 30 MR. Beyond that, it's really up to the particular player in how much MR they want to build.

Just remember that flat penetration is more effective against squishies than tanks. If you're trying to decide whether you should get penetration for dealing with high-MR enemies, just get a and call it good.

Seriously, I can melt you with math if you really want me to, but just trust me on this one.