This likely isn't what you meant.....but tying damage to things other than hit points, like smite uses or spell slots or other things would be cool, but likely a death spiral type situation. I think there might be times to make the players really desperate to end things quickly, or to run......and taking away "what" they are might be "fun" once in awhile.Yes! That approach makes it easier to zero in on what each character has at stake.