Hit Points

Hit points(HP) represent how robust and healthy a creature is. Wounds subtract hit points, while healing (both natural and magical) restores hit points.

Hit Dice (HD)
Hit points are gained every level based on a hit dice roll determined by the creature's class or type. The Hit Dice is the type of dice used to roll (between d6, d8, d10 or d12). The number rolled is added to the creature's maximum hit point plus an amount equal to the creature's Constitution modifier. The base amount gained per level is based on the amount of focus the class has on physical combat, with the more martial classes such as barbarian, fighter, and paladin receiving more.

Temporary Hit Points
Some abilities and spells grant temporary hit points that disappear after a certain duration. Attacks will normally remove temporary hit points before they remove permanent ones.

Effects
When a creature's hit points drop below 0, it becomes unconscious, sometimes known as disabled. When a creature's hit points reach a negative total equal to its Constitution score, it dies.