I searched the books (CRB, BFK, ITTS, LOTE, DH & RHB) and this forum and cannot find anything about how armor is damaged. Page 275 CRB 'Upkeep Tests' mentions… armor suffering massive damage… Ok, so how & when do you determine that?

I came up with a couple of options.

Op.1. Treat armour the same as 'Damaging Cover' (CRB, pg. 247). Calculate damage as usual, if the remaining damage is greater than the AP of the armour for that location then it is reduced by 1 point.

+ Armour with higher AP is less likely to be reduced.

+ Easy bookkeeping.

- Lower armour AP will get chewed-up fairly quickly.

Op. 2. Use the WFRP 2ed. Old World Armoury, pg 24 & 26. optional rule. Calculate damage as usual, if the remaining damage is 7 or more points, roll 1d10 and if a 1 is rolled the AP is reduced by 1 point for that location. WFRP also required 3 criteria, 1. Takes a critical hit; 2. Damage 7 or greater; 3. Hit with Ulrics Fury (Righteous Fury), which is redundant, the 'Fury' will exceed the 'greater than 7' criteria. To simplify it I would use the 'damage 7 or greater' only.

+ Applies regardless of the armour type and AP.

+ Easy bookkeeping.

- Applies regardless of the armour type and AP.

The 1d10 roll could be added to Op. 1 which would reduce the chance of reduction.

Change Op. 2 base '7' up or down to make it more or less 'grim and perilous'.

Most RT will have enough armour in reserve aboard ship so they can attempt upkeep tests accordingly or as the GM see fit.

Thanks for taking the time to read this and any input you have to share.

Op 3) GM Fiat. If you feel it's appropriate for armor to have become damaged from an attack it has become damaged from the attack.
At least that's how I'd do it since everything else is just to much bookkeeping, especially Op. 2. Op. 1 is equally flawed in that Power Armor can be useless after getting hit by just a few bullets.

I agree with musclewizard whatever feels right for the GM. I look at it like this if the character is in danger of dieing due to critical damage the armour is probably getting shredded by those hits. Even if they're not some cosmetic damage could certainly be in order bullet holes, scorch marks, etc.

As for those flak greatcoat wearing gunslingers add a few holes that need patching if they dodged a hail of gunfire (always love seeing the character put their fingers through the hole of a near miss.)

Oh and please read cosmetic damage as roleplay flavor. Cosmetic damage shouldn't affect stats, only people's reaction to you. So you got an archmilitant who's been wearing the same patch ridden carapace for the past 3 sessions because mechanically it still functions, and they haven't found a reason to replace it yet. Well, have your npcs comment on it… other than that you could always just say at some point the armour is just too far gone to be patched and parts will have to be replaced. This works well given location specific modular armour.

Oh and patching is what you do when you don't have the need, equipment, materials, or quality craftsman available to properly repair an item. Patching that best craftsmanship carapace or powerarmour maybe prefferable to using lower quality replacement parts.

My thoughts