Hit-Points are a characteristic common to almost every game in one form or another. The Hit-Points of a character measure its physical well being. Damage causes a loss of Hit-Points, while healing restores them. Should a character (or monster) be reduced to 0 Hit-Points then it is dead.

In AD&D and other such games a character can accumulate lots of Hit-Points as they rise in level, allowing to withstand huge ammounts of damage and still survive, as appropriate for these heroic, combat oriented, games. Many other storyteller style games (and Cyberpunk/Horror games, where death is supposed to be a constant threat) have a fixed number of Hit-Points (e.g. 10) and seldom allow a character to gain any more than that.