Not really suggesting this as a feature since players generally die too quickly for a system like this to make much of a difference, but it could be food for thought for M:BG.
Basically this idea would involve repeated effective strikes to a bone/group of bones simulating greater sensitivity/damaged armor in that region, without something that feels awkward like crippling/bleeding.
Human Agents get slots for each logical group of "bones". (eg. shoulder.R, upperarm.R, forearm.R, hand.R would all belong in one group.)
The values of these slots start out at 0, and get reset each "life".
Example scenario:
Player Y has 50 armor.
Player X hits Player Y in bone "calf.L", and deals 50 initial raw damage. Since this "bone" group (left leg) was undamaged, raw damage does not get changed. After armor, it deals 10 effective damage.
Player Y's left leg "bone" group slot has 1/2 of the effective damage added to it, increasing it to 5.
Player X hits Player Y in bone "thigh.L", dealing 50 raw damage again. Since this "bone" group (left leg) was previously damaged, Player Y takes extra damage, increasing the raw damage to 55. After armor, it deals 13 effective damage.
Player Y's left leg "bone" group slot has 1/2 of the effective damage added to it, increasing it to 12.
Player X hits Player Y in bone "calf.L" again, dealing 50 raw damage again. Since this "bone" group (left leg) was previously damaged, Player Y takes extra damage, increasing the raw damage to 62. After armor, it deals 17 effective damage.
...And so on until death.
