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Nut: I didn't know this was a thing. I jumped straight to the Mana Shield section and saw that there's some pseudocode explaining exactly how it's calculated and how it's applied. Such detail. Jarulf's Guide is a keeper.

I remember Mana Shield being OP a.f., and according to this guide, it actually got nerfed in Hellfire in a weird way, where increasing the spell level also increases the damage taken.
Mana Shield is EXTREMELY overpowered. If you combine it with the fact that if you have 30hp or less you don't get staggered when you get hit, well... :P