Exactly what is says on the tin - if my character is dealing both slashing and bludgeoning damage in a single hit, will the enemy's AA be subtracted from both my slashing and bludgeoning damage, or will it be subtracted from only one?
Unless it got changed after I heard that version, it divides AA by the number of damage types it affects (blasting can also be shrugged off with AA), rounding up, and then subtracts that much from each damage type. So, if a character with 5 AA got attacked by something that dealt crushing and slashing damage, both of these would get a -3 modifier to damage dealt.
My understanding is that the 3 basic damage types (slashing, blasting, and crushing) get added together, turned into a single packet of whichever type is dominant (and your melee power is added to that packet), and AA is subtracted from that. (Individual damage type resists are applied before the combining.) This is pretty easy to test with a dual-wield character -- just look at the damage ticker when you attack an enemy with AA.
Is the enemy effected the same exact way? I think a more verbose test would be required to say for certain.
TTBOMK, the enemies consistently use the exact same mechanics as the players. It's one of the things I like best about DoD: consistency.
From what I know when you hit an enemy with mundane damage, each type is individually affected by resists, then they're summed and the total damage is subtracted by . The total mundane amount is based on the sum of your and . So lets say an enemy has 1 2 and 3 You have 3 2 1 and 4. The resists are subtracted first, making 2 1. The is subtracted and you end up with 1 additional point of damage from . So the result is I believe 2 2 or something like that. By the end the damage types don't matter at all. If the were higher than your it would start to subtract from your slashing and then blasting damage since slashing was the highest. If you have 0 base damage, you deal damage. Because you have 0 base damage, it's not vulnerable to at all. For instance if you have 1 and 3 and the enemy has 2 and 1 then the 1 is dropped to zero by the and then your is added and subtracted so you have 2 damage left, resulting in a final damage of 2.