Hit Point

Hit points (often abbreviated "HP") are a measure of how much damage a character, vehicle. or structure can withstand before becoming useless. It's a hold-over from the simulation wargames that are the parents of modern role-playing games. Historically, it was Dave Arneson (the one who isn't Gary) who got the idea from some American Civil War navy wargames, because having your hero-characters die on the first hit sucked ass.

What Does It Mean To Lose A Hit Point

Hit points are an abstract thing (some systems, like Dungeons and Dragons, allow a player to have negative hit points), which freaks people out when they're playing the game as a simulation. "Okay, so I lose 3 hit points. Does that mean my shirt's ripped? I dodged it? I got a cut on my arm? What?" It gets worse when characters get more hit points from getting more power, skills or experience, but that doesn't change their appearance. It gets ridiculous when a character gets so many hit points that highly improbable events become common (i.e.: a level 13 fighter in Advanced Dungeons & Dragons has a better-than-half chance of surviving a fall from terminal-velocity heights).

Here are some explanations people use to explain hit points, and their ablative nature. Most DMs use a mixture of a few of these:

• They're a measure of fatigue, as the combatants parry and dodge blows. Only the last few hit points represent actually getting hurt.
• They're a measure of the effectiveness of the equipment the character uses to protect themselves; armor straps are cut, weapons get nicked, metal plates get dented. "Rest periods" include repair and maintenance of their gear.
• In the case of giant fighting robots, or spaceships firing on each other with lasers, the hit points are a measure of the ablative armor evaporating to rid the excess heat before it causes damage.
• The heroes of the story are lucky, since they are protagonists, but their luck can run out.

Specific Systems

• Dungeons & Dragons 3rd Edition has characters become disabled when they reach 0 HP, able to make only one action per turn. From -1 to -9 they are unconscious and dying, losing 1 HP per turn until they are stabilized -- either being magically healed by an ally, or succeeding on a Heal skill check, or the player rolling a 1 on d10 each turn. Once stabilized, they are still unconscious but can wake up by rolling 1 on d10 each turn. A conscious character with negative HP is disabled as if they had 0 hp, but doesn't regain hp up to 0. If a character's hp reaches -10, they are immediately dead. Taking 50hp of damage from a single attack forces a DC15 fortitude check; failure means death from massive damage.

• Dungeons & Dragons 4th Edition has characters become unconscious and dying when they reach 0 HP, and must be stabilized before they die. Until an ally uses their turn to stabilize them, the dying character must make a Saving Throw (roll d20, hoping to get 11-20) each turn to stabilize themselves. A character who has dying status for three turns is dead, even if they aren't three turns in a row; taking an eight hour "extended" rest resets the count ("three strikes yer out"). Dying character will still take damage from attacks, environment or area effects, and will be immediately dead if they take half their maximum HP after reaching 0 hp, even if they still have dying saving throws left or they were stabilized (e.g. a character with 24 hit points is unconscious and dying at 0, and immediately dead at -12 hit points). A common cause of death in 4e is ongoing damage that continues after they fall to 0hp, or area attacks while dying.

See also: "What the fuck is a healing surge ?"