Drain resistance

Drain resistance (also known as level drain resistance) is the intrinsic ability to resist a monster reducing your experience level.

Messages

"<Monster> suddenly seems weaker!" A monster without drain resistance has been hit with a draining attack.

"<Goodbye> level <x>." You have been drained a level.

Ways to lose a level

The attack of a monster with a drain life attack. All monsters represented as V or W have this attack, as does Demogorgon.

Getting hit by The Staff of Aesculapius' attack.

Being seduced by a foocubus and getting a negative effect (one of five such effects possible). If the compile-time option SEDUCE is not enabled, foocubi become level draining monsters similar to vampires.

Prayer before the timeout expires (one of many effects possible).

Directing the spell of drain life at oneself.

In SLASH'EM, having a wand of draining zapped at you; this is particularly troublesome in the Guild of Disgruntled Adventurers.

Ways to get it

Drain resistance is intrinsic in vampires, lycanthropes, Death, and undead monsters; wielding Stormbringer, Excalibur or The Staff of Aesculapius grants extrinsic drain resistance. Also magic cancellation can protect you from level drain.

In SLASH'EM, one can wear deep dragon scales or deep dragon scale mail, or wear an amulet of drain resistance.