Hit points represent a character’s ability to withstand damage and keep fighting. A character’s base hit points are equal to their Constitution score, plus any points gained from their race or class. A character gains a certain number of maximum hit points based on their level; these are added to their base hit points to determine their total maximum hit points.
Attacks which would harm your character are normally subtracted from your hit points. A character who has lost half their total hit points is bloodied; certain actions and effects only affect a bloodied character.
If you would take more damage than your current hit points, your hit points drop to zero - you never have "negative" hit points. However, if you would take more damage than your hit points, remaining damage directly reduces your Constitution score on a one for one basis.
While hit points represents a character’s ability to withstand damage, A character’s actual health and survivability is determined by his Constitution score.
Whenever you are reduced to 0 hit points by an attack, you are dying, and must begin making Endurance saving throws during each of you turns to attempt to stabilize; each failed saving throw causes you to lose a point of Constitution. Since your base hit points are based on your Constitution score, his means that characters who come back from the dying condition will have slightly less hit points available to them until they spend a day or more resting and recuperating, as well as lowered Endurance and Fortitude.
Critical hits, the dying condition, and certain particularly grievous attacks can cause damage to your Constitution. Whenever your character (or any creature) suffers a critical hit, it automatically suffers an equal amount of Constitution damage.
When your character's Constitution is reduced to 0, they are dead.
Optional Rule - Lingering WoundsEdit
Characters who want to play a more gritty game may utilize the following rule for detailed critical hit damage:
Whenever a character suffers one or more points of Constitution damage due to a critical hit, roll 1D20 + the amount of damage dealt by the hit, then subtracts the target’s Fortitude defense. Apply the indicated condition (if any) until all of the target’s vitality damage is fully healed.
Roll Result Lingering Wound Effect 0 or lower No Effect 1 to 2 Cannot use main hand 3 to 4 Cannot use off hand 5 to 7 Slowed 8 to 9 Weakened 10 Deafened 11 Blinded 12 Dazed 13 or higher Stunned
Particularly gritty settings may wish to force players to make an Endurance roll during each extended rest in order to regain a point of vitality; a failure means no vitality is regained during that rest, while a critical success means two points are regained, and a critical failure means that one Lingering Wound effect becomes a permanent affliction until healed with high-level magic. One character may make a Heal check once per day to attempt to aid healing; if they succeed, one additional point of vitality is healed, and on a critical success two additional points are regained. A critical failure on this Heal roll should be treated as a critical hit from a weapon, inflicting damage equal to the character’s heal value.