For questions about hit points, an abstraction of a health common to many RPGs.
Hit points (HP) are an abstraction of a character's health. Damage suffered is subtracted from hit points and healing restores them hit points to the original maximum. Depending on the RPG, characters may have a fixed amount of hit points derived from their statistics, or may increase their maximum number as they advance.
Hit points are common to many RPGs as they were the first health abstraction "design technology" to appear in an RPG system, with the publication of D&D (1974). An RPG may use hit points to represent a character's overall health, or it may give characters multiple pools representing different aspects. Hit points may be the only measure of health and injury, or may be combined with systems for wounds, debilities, effects based on HP level, or other permutations on the basic theme.