Wise Turtle Publishing

Check out this optional rule:

"At the Game Master’s discretion, should your Health reach zero, you may temporarily take a -1 Weakness to reflect a particular injury. This can be in place of or in addition to the -1 penalty you receive for reaching zero Health. Though the Weakness is temporary, its duration is indefinite until you’ve taken measures to heal it."

PDQ (as used in titles like Truth and Justice) has all injuries treated in a similar fashion. Every blow you take, you knock a point off of one of your Traits.

I've considered including "injury" rules as an option in OVA. Currently it's in a "making it gritty" sidebar, and amounts to you receive a "permanent" -1 Penalty every time you take half your health. This represents staggering blows, vicious stabs, and other dramatically appropriate injuries. Extra Knockback and Decreased Knockback do not affect this; it's always half your health.