Damage and healing affect hit points. Healing also involves recoveries.
Every creature has hit points. You slay enemies (or occasionally knock them out) at 0 hp. PCs at 0 hp begin using the Death and Dying rules.
Each PC starts the adventure with 8 or 9 recoveries, a stat that represents the PC’s ability to heal or bounce back from damage. Many healing spells and potions require you to use up a recovery. So does rallying during a battle.
When you use a recovery, regain lost hit points by rolling recovery dice equal to your level and adding your Constitution modifier. Your class indicates which recovery die to use.
At 5th level, double the bonus you get from your Con modifier. At 8th level, triple it.
If you perform an action that requires a recovery but have none left, you get half the healing you would otherwise get and take a –1 penalty to all defenses and attack rolls until your next full heal-up. This penalty stacks for each recovery used that you don’t possess.
When you are reduced to half your hit points or fewer, you’re staggered. Some powers, spells, and monster interactions work differently when you are staggered.
In general, monsters become staggered when they take damage equal to half their hit points or more, but it’s up to the GM.
When you drop to 0 hp or below, you fall unconscious. You can’t take any actions until you’re conscious again, though you do make a death save at the start of each of your turns. (See Death and Dying.)
When monsters drop to 0 hp, it means they’ve been slain, unless the characters’ intent is to keep the monster alive and the attack seems like a potentially humane blow that could knock the monster unconscious instead.
Death and Dying
When you drop to 0 hp or below, you fall unconscious and can’t take any actions (except to make death saves).
To make a death save, roll a d20 at the start of your turn. If you roll 16+, use a recovery to return to consciousness and heal up to the number of hit points you rolled with your recovery. If you roll a natural 20, you get to take actions normally that turn. If you roll 15 or less, you take one step toward the grave. After the fourth failed death save in a single battle, you die.
You also die when you reach negative hit points equal to half your maximum hit points.
If you’re able to use one of your recoveries (or otherwise get healed) while you are dying, ignore your current negative hit points. Start from 0 and add the hit points you’ve regained.
If one of your allies is unconscious and you don’t have magic to heal them, you can still stabilize them to keep them from dying. Get next to them and make a DC 10 healing skill check using Wisdom as a standard action. Failure wastes your standard action, but doesn’t hurt your friend. Success stabilizes your ally. If your stabilization check is 25+, you treat their wounds so quickly that it only takes a quick action; you can use your standard action normally that turn.
A stabilized character is still unconscious, rolling death saves on their turn, but failed death saves no longer take them a step closer to death. Ignore failed death saves while stabilized.
Feeding a dying character a healing potion gets them conscious and back on their feet, but always takes a standard action.
Optional Lasting-Wound Rule
If you’re dropped to 0 hp or below one or more times during a fight, you take a lasting-wound. Each lasting-wound reduces your maximum hp by an amount equal to 2 + your level. Lasting-wounds are cumulative. Staggered is still half or less of your maximum hit points. A full heal-up removes all lasting-wounds.
Optional Meaningful Death Rule
PCs can only be fully slain by named villains. PCs who fail four death checks fall into a coma and can only be brought back to consciousness once they’re fully out of danger.