Hit points or health points (HP) is the amount of damage a unit or building may take before being destroyed.
Terran structures lose 1 HP per second while their hit points remains below one-third of maximum. Structures may be destroyed if left to "burn down".
In the StarCraft II: Wings of Liberty campaign units and buildings gain regeneration through upgrades. The Regenerative Bio-Steel upgrade from the laboratory allows mechanical units to regenerate, and the Fire Suppression System upgrade from the armory allows structures to self-repair to 50% health.
All zerg units and structures slowly regenerate hit points automatically. Damaged units create damaged eggs when they morph, but regain full hit points when they complete morphing (from one unit to another). Structures do not regain any hit points when they complete morphing (from one structure to another).
By themselves, the protoss have no way to regenerate hit points. Instead, part of their unit and structure vitality is invested in shields. Shield points must normally be depleted first before the underlying hit points are affected. Shield points regenerate automatically over time.
The protoss have both armor and shield upgrades.
In StarCraft, a shield battery may restore shield points at an energy cost. The science vessel's EMP Shockwave reduces all shields in the area of effect to 0 points. Some abilities, such as the defiler's Plague, ignore shields.