My 2 cents about armour is something that perhaps not many people have considered: have the material that the armour was constructed from have other effects. What I mean is, metals are relatively good conductors. So depending upon the metal even, the player wearing said armour is effected differently by lightning based spells/abilities. Perhaps a hide is more flammable than a suit of chain, etc. This could surely add some realism; I like this idea 'cause I just hate the trend to so completely balance everything in games to the point of boredom. If I'm enjoying sword blows bouncing off my full plate, it would be cool suffer a bit more at the hands of a tempest wielding mage (or whatever). Even if such an idea was considered, it can be approached in a creative way - it doesn't have to be a case of "full metal armour = 30% more damage from sources of lightning damage." I can't think up a terribly clever way at the moment, but hey, just some ideas.
