Health in Pendragon is measured in Hit Points, which function pretty much as you'd expect from games like Dungeons & Dragons. You lose Hit Points directly by suffering injuries; you can also lose points indirectly through terrible medical practices, specifically Aggravation and Deterioration of prior wounds.
Any time some fool smites you, you lose Hit Points. If the damage exceeds your Knockdown score, roll against your DEX or Horsemanship to see if you stay upright. Then, your armor (and maybe your shield) soaks up the damage. If any damage gets through your armor, subtract it from your Hit Points, and write down that wound.
Compare the net damage to your Major Wound score. If it's less than your Major Wound threshold, hey it's just a flesh wound. But if a single blow equals or exceeds your Major Wound threshold, you're hurting bad, and lots of sad things happen:
- Roll against current Hit Points or fall unconscious
- Roll against your Valorous trait to stay in the fight
- Roll on the Statistic Lost table to see if you're mangled for life
- Mark off the "Chirurgery Needed" box - you're at risk of Deterioration
- Further action may cause Aggravation to the wound
If a single injury takes away all of your Hit Points, that's a Mortal Wound and lots of bad things happen:
- you will die unless your Hit Points reach 1 within an hour
- if you get to 1 Hit Point, roll three times on the Statistics Lost table
- mark the "Chirurgery Needed" because you're at risk for Deterioration.
Dying straight up!
If you reach 0 or negative Hit Points, you will die unless you get back up to 1 Hit Point or more by midnight. Mark off the "Chirurgery Needed" box.
Aggravation and Deterioration
Aggravation happens when you don't take it easy after getting seriously injured: you might lose anywhere from 1-3 Hit Points depending on the activity. (Simply riding on a horse or walking might cost 1 Hit Point!). You prevent Aggravation by not being an idiot.
Deterioration occurs when you don't get proper medical treatment after a really grievous wound and diseases set in. Typically you lose 1-6 Hit Points per week. Deterioration is prevented by Chirurgery.
Regaining Hit Points
You can get better from First Aid, natural healing, Chirurgery, or magic.
You can get First Aid once per wound, and only if you get healed within a day. So if you took 5 points of damage falling off your horse, and someone heals you 3 points through First Aid, the remaining 2 points cannot be healed by First Aid: you had your chance already.
You recover a certain number of Hit Points once a week, by convention on a Sunday. If you received a total of 15 points of damage, and you recover 3 points per week through natural healing, you are out of the action for five weeks, my friend! Unless you're willing to risk riding out with some pretty serious injuries, putting yourself at risk for a nasty death spiral…
Chirurgery is a skill to treat sepsis and other problems. Chirurgery doesn't normally heal damage, rather it prevents Deterioration for a week.