So I'm messing around with a tank (Marauder) in the beta and I just hit level 15. Now I have some armor from dungeon runs I did as a lancer that's i17 and some lv 15 bronze armor from a quest. The bronze armor is a huge boost in DEF (+13) over the i17 but is +2 VIT vs the +3 VIT of the i17 armor. Now obviously I can see VITs effect in my HP easily enough by switching armor and doing the math. What I can't seem to find is exactly what DEF does anywhere, including the wikis. Is it just a straight 1:1 damage mitigator?