As I was thinking about what stun multiplier to use for killing attacks, it occurred to me that not much hurts less than a killing attack that doesn't penetrate resistant defenses and not much hurts more than a killing attack that doesn't meet any resistant defenses. For instance, even a hard stab with a dagger against rigid armor that stops the body completely wouldn't hurt very much, but a deep wound with the same dagger would hurt a lot. So I thought about how to model that.
I am considering using a stun multiplier of 2 on the base attack, then the same multiplier on any body that gets past resistant defenses. The stun for the body done would be extra stun against no defenses. Increasing the stun multiplier would increase the multiplier on both parts of the attack.
For example, a killing attack that did 8 body, 16 stun vs 8 PD, 8 resistant PD would do 0 body, 8 stun. If it was vs someone with just 8 PD, 0 rPD, it would do 8 body, 8 stun, then another 16 for the 8 body done.