Re: Combat
I was thinking about this conversation, peacefully resting though it is, and I decided to perform some pseudo-necromancy on it.
I think the idea is to actually get some mileage out of SDC in this game, and make battle a bit less binary - either you have MDC armor/defenses and you live, or you don't and the next hit kills you.
Instead of reducing MDC when it hits an SDC target, I have an alternative: blowthrough damage, or chip damage.
The principal behind this is simple - the armor saves your life, but you still just got hit with an anti-tank missile. That's gonna hurt, armor or not. So, we have some of the damage go through as SDC, either on a point for point basis (which my brain says is a mistake) or at reduced value, somewhere between 10% to 20%.
Example - 30 MDC mini-missile. Take anywhere from 3 to 6 SDC damage, and you are probably thrown through the air like a ragdoll, which probably won't deal extra damage...unless intense bludgeoning forces like gravity are critical weak spots in MDC armor defenses, which could create a whole new style of combat in its own right, one more akin to streetfighting than honorable combat.
Armor-piercing might actually do extra (double?) damage to the wearer, because it is designed to mess up armor.
This is only for worn or powered armor, sadly, but it could probably be adapted for vehicles. Just...a bit of caution here. This could either be meaningless (in which case it is extra bookkeeping that wastes time), or it could render the armor worthless less meaningful, as being KOed is still better than being killed.
This does also create the possibility of a mob grabbing you and just beating you to death by hitting you against objects. The armor? It's fine, not a scratch - the wearer, on the other hand...