There seem to be several items that increase our characters spell resistance but I can't find an explanation of the math mechanics or a discussion of how much spell resistance is enough. How does spell resistance compare to "protection of the elements" type items? I found a robe of resistance that gives me +17, I had 0 before, and that looked like a high number to me especially since items I have picked up to overcome a mobs spell resistance only give me a +1 or +2 bonus increase, which I assume does not stack but please correct me if I am wrong. Will that +17 protect me most of the time against a bolt of lightning or other elemental type spell and does it work to resist any spell? Final question I promise, do the spell resistance items stack? Any insight is greatly appreciated