Magic resistance (monster)

Monsters have innate magic resistance, also known as MR. This is separate from the magic resistance provided via various worn or carried items. It is given as a number between 0 and 100. This is frequently given as a percentage, although this is not entirely accurate.

Monsters' magic resistance allows them to resist various attacks, generally of a "magical" nature. It is handled by the resist() function. If a monster successfully resists an attack, it takes roughly half damage.

The chance of a monster resisting is given as follows:

Chance = MR/(100 + (attack level) - (defense level))

which is only equal to MR as a percentage when attack and defense level are equal.

Attack level is calculated as follows:

Source	Attack Level
spell	Caster's level
wand	12
tool	10
weapon	10
scroll	9
potion	6
ring	5

Defense level is the level of the defending monster (max 50).

All this also determines the chance pets resist conflict.

So at level 30, the Riders are truly magic resistant, but & Pestilence and & Famine can be affected if their level is drained (& Death is resistant to drain life).

Monsters can also gain "regular" magic resistance by wearing a cloak of magic resistance or gray dragon scale mail. However, its scope is stricly smaller than monster magic resistance, e. g. taming and conflict are not affected, while polymorph traps become ineffective.

Messages

"Foo resists!"

A monster resisted an attack. Shown only in some cases.

References

This page may need to be updated for the current version of NetHack.

It may contain text specific to NetHack 3.4.3. Information on this page may be out of date.

Editors: After reviewing this page and making necessary edits, please change the {{nethack-343}} tag to the current version's tag or {{noversion}} as appropriate.

A user has suggested improving this page or section as follows:

"A list of all effects subject to monster mr, and/or confirmation that all those effects mention they are subject to it and link here."