this is a house rule that my players and I came up with.
this should be prefaced with the fact that my friends are insane
all armor is treated in a similar way as Cover, every 3 hits that exceeds the AP value of the armor, reduces the AP for that location by 1. in addition to the armor being no longer environmentally sealed after 1 hit as normal
if the AP is reduced to 3 AP on any one location, there is a chance of damage one of the many sub-systems of the armor, system damaged and % is determined by location:
Head: 30% chance of knocking out auto-senses
arms: 40% change of knocking out Recoil Suppression
Chest: 50% lose 1d5-2 doses of pain suppressors (min 1), 40 % change of disabling Nutrient recycling, 10% chance of entirely disabling Bio-monitors and injectors.
Power Core damage:
we really enjoyed the backpack critical damage table, but decided to make it a little more interesting.
any penetrating hit from the back that deals to the body or head has a change of damaging the power pack, the chance of damage depends on how many AP are left.
10 AP = 0%, 9 AP = 5 %, 8 AP = 10%, 7 AP = 15%, 6 AP = 20%, 5 AP = 25%, 4 AP = 50%, 3AP = 60%, 2 AP = 70 %, 1 AP = 90%, 0 AP = 100%
the backpack has its own set of AP separate from the body, and the effects are those listed on the table, 1-3, no effect, 4-5 damaged, 6+ unpowered
Repair Cement: RC seals a breach and restore 1 AP to the location, however, to represent that this is just a stopgap measure, the restored AP is ablative, meaning that any hit on the location will strip that AP, regardless of if the shot penetrated.
Power armor repair takes 2 hours for every AP lost (up to a maximum of 42 AP) for a tech marine, given the correct materials and facilities, this time can be shorted to 1 hour per AP if multiple techs work on the armor, but it can never take less that 1 hour per AP as all the rites must be performed.
Backpack repair: 2 hours for every AP lost, in addition to 8 hours per critical damage acquired by the backpack (max 6 critical damage). this time can be reduced to 1 hour per AP as above, and 3 hours per critical damage.
so there it is, we are still tweaking it, any suggestions are welcomed. the point of this was to make cover vital, a marine can still take alot of oncoming fire outside of cover, but his armor shouldn't be pristine at the end of the day
*edit - minor errors, added FatPob's suggestion*