Actually, armor simply subtracts dice from incoming attacks.  Which isn't a terribly elegant way to do things, but it keeps it from being overpowering.  (Which is good, because Mages can get armor ratings of 6 or higher with very little effort, which would render them practically invincible.)<br/><br/>The only situation in which armor subtracts damage is against explosions and swarm attacks, neither of which apply in the current battle.