Puggins
Explorer
I'd coopt the death/dying rules.
When you go negative:
Each round, make a save:
1-9: you've suffered a serious wound. You suffer a -1 (cumulative) penalty to all str, dex and con checks. You must rest 24 hours for each -1 penalty in order to remove it, or have a cleric perform a healing ritual to restore you.
10-19: Nothing happens.
20: You jump up and recover 25% of your hit points. If you had suffered at least one wound during this specific crisis, the number of wounds is reduced by one. Turns out that your wounds are not as severe as they initially appeared.
When you go negative:
Each round, make a save:
1-9: you've suffered a serious wound. You suffer a -1 (cumulative) penalty to all str, dex and con checks. You must rest 24 hours for each -1 penalty in order to remove it, or have a cleric perform a healing ritual to restore you.
10-19: Nothing happens.
20: You jump up and recover 25% of your hit points. If you had suffered at least one wound during this specific crisis, the number of wounds is reduced by one. Turns out that your wounds are not as severe as they initially appeared.