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.
Monsters' magic resistance allows them to resist various attacks, generally of a "magical" nature. It is handled by the resist()[1] function. If a monster successfully resists an attack, it takes roughly half damage.
Monsters can also gain player-style magic resistance by wearing a cloak of magic resistance, gray dragon scale (mail), wielding/carrying Magicbane, or using certain quest artifacts. In addition, a few monsters have it intrinsically, separate from their monster MR. However, its scope is loosely smaller than monster magic resistance. For example, taming and conflict are not affected, while polymorph traps become ineffective. Neither type of magic resistance will protect monsters from level teleporters.
Players cannot ever gain monster-style resistance, e.g. through polymorph. Players must instead rely upon magic cancellation and magic resistance, which can complicate forms that cannot wear armor.
Contents
Calculation
MR is given as a number from 0 to 100. This is frequently given as a percentage, although this is not entirely accurate.
The chance of a monster resisting is given as follows:
Chance = MR/(100 + (attack level) - (defense level))[2]
which is only equal to MR as a percentage when attack and defense level are equal. Zero MR monsters will never resist.
Attack level is calculated as follows:
| Source | Attack level |
|---|---|
| spell | Caster's level |
| wand, polytrap[3] | 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 monsters (including pets) resist conflict. Conflict always counts as ring.
So at level 30, the Riders are truly completely magic resistant, but & Pestilence and & Famine can be affected if their level is drained (& Death is resistant to drain life).
Messages
- <Foo> resists!
- A monster resisted an attack. Shown only in some cases.
Variants
FIQHack and NetHack Fourk call this willpower to distinguish it from magic resistance, and xNetHack calls it magic saving throw. Except for this, it generally works the same as in vanilla, except that in FIQHack, the attacker bonus from wands depends on wand skill.
References
This page may need to be updated for the current version of NetHack.
It may contain text specific to NetHack 3.6.0. Information on this page may be out of date.
Editors: After reviewing this page and making necessary edits, please change the {{nethack-360}} 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."
