Dirt Simple First Aid

Whenever you are in a dungeon, out in the wilderness, or in an adventure location, you can take a short rest (exploration turn) to perform various actions. One of these is healing.

In order to heal another party member, you must expend bandages (or healing herbs) to heal them. You heal them 1d6 + your Intelligence modifier and the healing item is consumed. Your character can also be trained in the arts of healing, either as a class feature or as training that can be purchased in downtime (similar to weapon training, or studying for new spells). Every time you train your healing, you can increase the amount you heal by +1.

Certain hazards, rusted blade-traps, the undead, and complex injuries become aggravated. This means that the injury deals its normal Hit-Points effect of damage, but any healing roll made to heal that character is now made at a minus, and subtracts the amount you heal with your healing action by that amount. For example, a triangular bayonet is very difficult to stitch up, and has a aggravated wound value of -3, the touch of a Wight would be -7. This means that attempting to heal it while unskilled can actually make it worse. (This acts as an incentive to have dedicated healing-focused characters to be able to safely restore health, and reduce healing effectiveness overall).

Additionally, certain items like healing potions and food heal when consumed, which do not trigger aggravated wounds. Regular rations consumed on a short rest restore +1 Hit-Points. This means that even if you're cursed and burned with acids and all other sorts of shit, you can still recover a little bit of HP in a safe if time-inefficient way.

This system is the trimmed down version of this.