Regeneration
Regeneration is a property that speeds the recovery of HP drastically; your character gains 1 HP on every turn they would not normally do so.[1]
It is acquired as an extrinsic through putting on a ring of regeneration or wielding the Healer's quest artifact, the Staff of Aesculapius. It can only be acquired as an intrinsic by eating a ring of regeneration if the ring is of suitable material and you are polymorphed into a monster that can eat it, or by polymorphing into a monster with innate regeneration: all vampires, vampire bats, werecreatures, imps, lemures, quasits, all trolls, all liches, Archons, the Wizard of Yendor and Riders.
Regeneration also burns nutrition faster; namely, one point of it every odd turn, unless the source is an artifact.[2] Note that a digested ring of regeneration will use nutrition. This may be a good or a bad thing, depending on whether there is a scarcity of food or a corpse that you wish to eat; the former tends to be the case in the early game, whereas the latter situation is common in the late game.
The following information pertains to an upcoming version (NetHack 3.7.0). If this version is now released, please verify that the information below is still accurate, then update the page to incorporate it.
As of commit f3408b87, the regeneration property unconditionally heals 1 HP on all turns, regardless of regular HP regeneration.See also
References
