Well some spell damage is unavoidable. Bloodbolt Whirl from Queen Lana'thel, Mutated Plague from Professor Putricide, Pungent Blight from Festergut (inoculation of course mitigates a lot of this) as well as random targeting factors like Napalm from Mimiron, Vile Gas on Festergut. Just a few examples.Originally Posted by Clown.Eround
It isn't to say you can't live without it but it is commonplace to spec into it. No harm no foul.