Summon nasties is a monster spell. It is a mage spell that can be used by monsters of level 16 or higher.
If you are in Gehennom, there is a 1⁄10 chance that a demon is summoned. Otherwise, a number of hostile nasties will be generated around the caster. Summoned spellcasters will have a lower difficulty than the caster. & will not summon A, and vice versa. On the Rogue level, nasties not represented by an uppercase letter are less likely to be summoned. Summoned monsters will be unable to use special attacks such as breath weapons for d4 turns.
Nasties will be summoned until either d(XLvl) nasties which are neutral or co-aligned with the summoner have been created, or the maximum of 10 nasties have been created. Because of this, monsters of alignments with fewer co-aligned nasties will summon more nasties on average. Remote summoning by the Wizard of Yendor is considered neutral for this purpose.
Monsters summoned in this fashion respect genocide, but not extinction. If a genocided monster would be summoned, it is replaced by an ordinary random monster (which is not guaranteed to be hostile). Spellcasting monsters generated this way need not be lower in difficulty than the caster.
Dealing with this spell can require actions both before and after it is cast:
One option is to genocide the worst nasties: arch-liches and master mind flayers are good candidates for this. However, if the spell attempts to generate a genocided monster, it will instead generate a random one. Once the player has the Amulet of Yendor and is out of Gehennom, Archons and ki-rin are not unlikely random monster choices and may be summoned in place of genocided monsters.
One good option for a player with a scroll of genocide would be to blessed-genocide L. Liches are by far the most frequently encountered casters of summon nasties, and also the only ones that can be genocided anyway. Doing so will genocide only one nasty, arch-liches, and so will not greatly increase the probability of Archons being generated by the spell.
When meeting a summoner
The worst place to meet monsters with this spell is on large open levels, such as Juiblex's swamp. On such levels, a summoner will often sit outside of a ring of monsters it has created around you, and continue summoning even as you attempt to fight off its minions. In this situation, the covetous behavior can be helpful; an arch-lich that warps to the upstairs may no longer be in sight, whereas a fleeing demilich will remain in sight and continue to fill the level with nasties.
If you are unable to kill the caster, such as an arch-lich that warps to the staircase across the map on a no-teleport level, and possess reflection and a permanent Elbereth, it is possible to wait on the Elbereth square for the caster to create a black dragon and wait for the disintegration breath to destroy the summoner, or possibly for a cockatrice to be generated and leave a corpse. This can be a life-saver if any of the demon princes appear as well.
Another way to counter the summon nasties spell is with a ring of conflict. The monsters will fight one another instead of focusing on you. A scroll of taming or spell of charm monster are also effective, although many nasties have a substantial chance of resisting either one.
- A monster appears from nowhere!
- One monster was summoned.
- Monsters appear from nowhere!
- Multiple monsters were summoned.
- <A monster appears/Monsters appear> around <a spot near you/your displaced image>!
- The summoner was fooled by your invisibility/displacement. The summoned monsters may still be able to find you.
- "Destroy the thief, my pet(s)!"
- The Wizard of Yendor cast the spell while alive. (The summon nasties effect that the Wizard uses to harass you in his absence displays no message.)
These monsters are "nasties" for the purposes of summon nasties:
In SLASH'EM, these monsters are also nasties in addition to those above:
The following monsters were removed from the list of nasties:
Before NetHack 3.6.1, the list of nasties was the following. Nasty selection on the Rogue level was not biased toward uppercase letters in these versions. The number of nasties did not depend on their alignment, and was simply d(XLvl).
- L arch-lich
- q baluchitherium
- D black dragon
- @ captain
- Y carnivorous ape
- c cockatrice
- A couatl
- R disenchanter
- @ elf-lord
- @ Elvenking
- H ettin
- E fire elemental
- H fire giant
- D green dragon
- P green slime
- g gremlin
- ' iron golem
- J jabberwock
- q leocrotta
- h master mind flayer
- H minotaur
- j ochre jelly
- O ogre king
- T Olog-hai
- Y owlbear
- w purple worm
- D red dragon
- T rock troll
- E stalker
- U umber hulk
- V vampire lord
- g winged gargoyle
- x xan
- X xorn
- D yellow dragon
- z zruty