- This article is about the effect; for the spell, see Regenerate (spell).
Regeneration is an effect and item property that causes the subject to heal damage over time. This is usually a fixed number of hit points recovered each round, but the effect version can have a different period between recoveries. (If regeneration is expressed solely as a number, "hit points per round" is implied.) This is distinct from vampiric regeneration, which only cures hit points when damage is inflicted on someone else.
Regeneration stacks with itself, even in cases when stacking usually does not occur (same spell or multiple properties on a single item). More accurately, multiple sources of regeneration are simultaneously active, each healing its set amount of hit points when its timer is up (not the sum of all regeneration sources being added at once). However, this distinction from true stacking is rarely significant (unlike the wounding case).
The two spells that produce regeneration are monstrous regeneration (for 3 hit points per round) and regenerate (for 6 hit points per round). Of these, monstrous regeneration has a special check that prevents stacking by removing the effects of any earlier castings of that spell.