game design type thread: while obviously what mechanics are best for your game will vary with what you want, i think i've kinda ended up coming up with a solid mechanic for doing body armour that keep reusing because it just works so damn well lemme explain
basically, i treat armour as two numbers: a "Thickness", which is a value, and a "Coverage", which is a dice target. So X/Y+. Thickness is how thick or resilient the material is. Coverage is how much of the body it actually protects.
All weapons have some kind of Armour Penetration value which interacts with the Thickness; at its most simple, if AP match/Exceeds Thickness, armour can't help, or is at reduced effectiveness. Otherwise, armour can stop the attack.
When you get hit, you check AP against Thickness, then roll a dice. Did you meet or exceed Coverage? Cool, your armour stopped the attack. Otherwise, it hit somewhere the armour doesn't cover, and you take damage.
the real trick of this system is that *you can stack armour*. you always just use the best Coverage you have available and only roll once. so i can wear 1/2+ armour and 3/5+ armour; if the AP is 0, i can roll 2+, but against scarier stuff i need my 5+.
whats great is its simple, but you can so easily plug it into the input systems determining how your armour works in Flying Circus, you actually buy helmets, vests, etc, and it gives you more Coverage.
in Riposte!, armour saves only downgrade attacks (so lethal Wounds become temporary Injury), but armour *stacks* with the 6+ Miracle Save everyone gets, so if you have a helmet, a 6 can turn a Wound into getting away scott free.
Patrol: Second Tour has the most sophisticated version of this so far; you have 5 armour locations (legs, right/left arms, torso, head) each with their own armour. a 3/2+ kelvar vest won't protect your arms, no, but it almost always intercepts much more lethal chest wounds!
whats more, in Patrol 2, you roll for each point of *damage*, rather than each attack, so your 2+ armoured vest might stop 2 out of 3 points of Damage from an incoming bullet, still realistically leaving you with bruises or a broken rib.
this system is based on the Armour Save/AP relationship from 3rd Edition Warhammer 40,000, but the introduction of Thickness makes it much more flexible, giving you an extra lever which can make a distinction between, say, a knight in thin full plate and a 'munition plate' vest