Runes have hidden effects.
Resistance reduces AOE Magic damage, not all magic damage.
If you would like to see this for yourself, then go to a magic aoe heroic boss such as minister lascv, and fight him once using no resistance runes and once with high resistance runes on your physical heroes.
Or you can fight someone with a strong Mulan once without resistance and once with to see how it works in AOE.
On a related note, if you power up your Mulan or Smoulder/Purple Smoulder with infallibility, it will cause him/her/it to do more damage in PVP but NOT heroics/quests.
Then the other obvious special effect I can think of is Preciseness reducing Shayd's miss chance.



Reply With Quote