# Genocide
In NetHack, genocide is the act of wiping out all members of a certain race by magical means. This is unrelated to extinctionism, a voluntary challenge which consists of killing all the creatures in the game by yourself.

Contents

1 Description
2 Restrictions on genocide
3 Reverse genocide
4 Emergency genocide
5 Common genocides

5.1 Genocide by class (blessed scroll)
5.2 Genocide one species (uncursed scroll or throne)
5.3 Strategic genocide of quest monsters

6 No genocides
7 Wizard mode genocide
8 Variants

8.1 SLASH'EM
8.2 UnNetHack

Description
Genocide can take place in the form of a scroll of genocide or you may get to genocide one monster when #sitting on a throne. Genocides gained from a throne are always safe, while scrolls may not be if they are cursed or if you are confused.
If you want to keep a genocideless conduct, you can always answer "none" when asked what to genocide. Specifying an invalid race five times in a row will also result in nothing being genocided and your conduct will be preserved.
Genocide does not break the pacifist conduct. There is no penalty for genociding a species including current pets or peaceful monsters, but there is a small alignment penalty for a lawful that genocides a single human species; a chaotic gains a small boost to alignment for doing the same.
When a species is genocided, all living monsters of that species will be killed, and no new ones will generate. Genocide will also prevent monsters (and the hero) from polymorphing into the chosen monsters. Monsters killed in this way will drop their inventory, even if they are on a different floor.

Restrictions on genocide
The following creatures cannot be genocided:

all A angelic beings
all &amp; major demons, Riders, mail daemons, djinn, and sandestins
all ' golems
all E elementals, but not stalkers
H&nbsp;titans
:&nbsp;salamanders
all werecreatures
Z&nbsp;skeletons
&nbsp;&nbsp;ghosts and shades
all @ except nurses, doppelgangers, randomly generated elves, your own role, the Watch, and the Yendorian Army
all unique monsters
Don't blessed genocide @; additionally, don't blessed genocide h if you are a dwarf, G if you are a gnome, or o if you are an orc. And keep in mind that blessed genociding always wipes out the entire class even if you specify a particular monster. If you genocide your base race or role, you will die. Variants of your base race are safe to genocide; for example, as a gnome, you could genocide gnome lords or gnome kings, but choosing "gnome" to genocide is fatal. An amulet of life saving will not save you from death by genocide. This is usually only an issue with dwarves; see below.
Genociding @ while polymorphed  will result in a YAFM: "You feel dead inside." You will die if you revert back to your normal form, and the only way to survive is by wearing an amulet of unchanging, or either ascend or escape the dungeon before you unpolymorph.

Reverse genocide
Reading a cursed scroll of genocide will create 4–6 of the specified monster. This is what makes reading a non BUC-identified scroll of genocide dangerous. However, it can work to your advantage if the resulting monsters are useful and can be killed easily.
Here are some useful monsters to reverse genocide:

W wraiths: to eat their corpses for a level gain (average of about 1.6 corpses per scroll read). Don't do this on a level with a graveyard, or you'll get significantly fewer corpses.
D dragons: a dangerous way to make dragon scale mail
@ nurses: to nurse dance
i tengu: to eat for a possibility of teleport control
; kraken: easy experience as they are very slow out of water. Be aware that although they tend to run away, they still attack occasionally – but of course they cannot drown you out of water. (Average of about 7870 XP per scroll or enough to go from level 10 to 11. If you are level 11 or higher, wraiths are a better bet to level up.)
h mind flayers: to eat for intelligence gain; be sure to be standing on a scroll of scare monster
H giants: to eat for strength gain
u unicorns: to eat for poison resistance, to sacrifice if cross-aligned, to throw them gems for Luck if coaligned, and for unicorn horns to use as is or to polypile into other magical tools such as magic markers
w purple worms: combine with taming or ring of conflict and a wand of teleportation to easily clear out large open levels full of powerful monsters
c cockatrices: to use their corpses to quickly deal with powerful monsters (chickatrices are lighter but less likely to leave a corpse)
Vegetarians can reverse genocide gelatinous cubes for the intrinsics once they can defeat them and take the acidic corpse damage. Monks going for speed runs or the pacifist and atheist conducts will find that useful, because they do not want to lose alignment for eating meaty corpses. Alignment loss is relevant, because of the early game alignment cap for speed runners, and because raising alignment is so hard for pacifist atheists.
For monsters that you want to eat, especially those that provide a large amount of nutrition, it is valuable to have a tinning kit on hand when reverse genociding.
You cannot reverse genocide a monster that cannot be genocided or that has already been genocided or extinct.
Reverse genocided monsters do not spawn with any items, so you can't farm athames from liches that way. They do leave death drops such as unicorn horns and dragon scales.
Reverse genociding does not break the genocideless conduct.

Emergency genocide
The scroll of genocide is a useful escape item as it can instantly kill a monster which poses an immediate threat and cannot be dealt with in any other way. For example, a sea monster holding you, a single monster about to take your last hit point, or a nymph who is robbing you blind. (The nymph will drop whatever she is carrying, so you'll get your stolen items back.) Keep in mind however that some monsters cannot be genocided.

Common genocides
Some species are widely considered to be so nasty, or so annoying, that players commonly genocide them as soon as possible:

L, liches
h, mind flayers
;, sea monsters
R, rust monsters and disenchanters

The following information pertains to an upcoming version (NetHack 3.7.0). If this version is now released, please verify that it is still accurate, then update the page to incorporate this information.

Sphere explosions may damage or destroy items, making shocking spheres or all of class e worthy genocide targets.
It is nearly always best to postpone genocide until you can bless your scroll, because the worst monsters don't appear until later. This gives you plenty of time to build up a cache of holy water. Note that if you are a dwarf, genociding h with a blessed scroll of genocide is instantly fatal!

Genocide by class (blessed scroll)

Glyph
Monster
Reason

L
liches (4 kinds)
Curses inventory items, touch of death, and summon nasties.

;
kraken
Drowns you.

electric eel
Drowns you, plus electric shock destroys items.

giant eel
Drowns you.

h
mind flayers (2)
Note: Must specify h or humanoid to genocide both mind flayers, see below.

humanoids (5)
Includes dwarves, do NOT genocide these if you are one.

c
cockatrice (3)
Including corpses, multiple sources of instadeath through stoning, but corpses are powerful instakill weapons.

m
mimic (3)
Increases number of useful items in stores, especially in Orcus Town.

R
disenchanter
Reduces item enchantment, but trivial with MC3 and junk weapon or bare-handed melee.

rust monster
Rusts weapons and armor, but trivial with rustproof weapons and outer armor (such as any cloak, dragon scale mail, or non-metal armor as is often worn by spellcasters).

N
nagas (8)
Golden can curse, others often nasty. Other than golden, not worth it.

t
trappers (2)
Engulfing attack can instakill pets, but not much risk for players.

w
purple worms (2)
Engulfing attack can instakill pets, summoned as nasty, but not much risk for prepared players.

T
trolls (5)
Often an annoyance, but not really worth genociding. It is easier to kill the troll and put the corpse somewhere else or eat it.

D
dragons (18)
Breath attacks can be dangerous, but trivial if you have reflection. They also can give dragon scale mail, useful intrinsics when eaten, and often useful potions. Probably better not to genocide them.

q
quadrupeds (6)
Tough if low level. Not worth it at high levels.

V
vampires (2)
May increase number of wraiths in graveyards.

Z
zombies (7)
May increase number of wraiths in graveyards.

P
green slime
Can turn you into slime, but easily dealt with via magic cancellation and (in emergencies) a wand of fire or similar item. Eating their globs also causes sliming and provides no intrinsics whatsoever.

black pudding
Corrodes weapons and armor and has moderately powerful attacks, but globs can provide intrinsics.

brown pudding
Rots weapons and armor, but globs can provide intrinsics.

gray ooze
Rusts armor, but globs can provide intrinsics.

n
nymphs (3)
If you can't kill them from a distance or in one turn (and they stole something important).

Genocide one species (uncursed scroll or throne)

Glyph
Monster
Reason

h
mind flayer
Amnesia attack. Better candidate for blessed, UNLESS player is a dwarf.

h
master mind flayer
Amnesia attack. Better candidate for blessed, UNLESS player is a dwarf.

R
disenchanter
Reduces item enchantment, but trivial with MC3 and barehanded melee.

R
rust monster
Rusts weapons and armor, but trivial with rustproofing.

:
chameleon
Pets eat them and transform into worse pets.

@
doppelganger
Pets eat them and transform into worse pets.

b
gelatinous cube
Eats organic items (esp. bags and boxes).

v
energy vortex
Electric shock destroys rings and wands, BUT useful resting place on the Plane of Air.

g
gremlin
Sometimes steal intrinsics at night.

J
jabberwock
Tough opponent.  Not really worth it.

H
minotaur
Tough opponent, but carries wand of digging.  Not really worth it.

w
purple worm
Tough if low level. Engulfing can instakill pets, but makes a good pet.

U
umber hulk
An annoyance; confusion gaze and tunneling.

e
floating eye
Accidentally attacking one usually paralyzes you for a very long time unless you have reflection or free action, frequently leading to YASD even to high-level characters. However, they are also by far the most reliable source of intrinsic telepathy (the only other being (master) mind flayers), so this should generally be avoided unless you already have it, are chaotic, and plan to also genocide gremlins, in which case it may be a very good choice for an early genocide.

Strategic genocide of quest monsters
If a quest-related monster race is genocided, it will generate more monsters of a quest-related class. If this class has monsters which are useful (common reverse genocide targets), genociding the race has beneficial effects.

This role ...
... can genocide this ...
... to generate more ...
... and eat them for ...
... at the disadvantage of

Wizard
X xorn
W wraith
experience
no polyself into xorn

Caveman
h bugbear
h mind flayer
intelligence
mind flayers are dangerous

Knight
i quasit
i tengu
teleport control
(none)

No genocides
It can be argued that many species are a source of useful items and properties, and hence genociding actually makes NetHack harder. Liches sometimes provide athames, mind flayer corpses can boost intelligence, sea monsters are trivial for a well equipped player to deal with, etc. It is also impossible to polymorph into a genocided creature, which may limit your options in certain situations (such as using the mind flayer's mind blast to alert monsters to your presence). This viewpoint usually advocates genociding only mimics, as this will slightly increase the number of items present in shops, especially in Orcus Town.
Another possible exception is sea monsters, which although trivial can be annoying or cause YASD by inattention. These are not randomly generated, so genociding them does not affect random generation.  Since they typically live—and therefore die—in water, they are not normally a significant source of corpses or items (although electric eels are a potential source of shock resistance if you can recover the corpse). Electric eels and giant eels might make a good use of any single-species genocides that happen to be granted, saving mimics for a class genocide.
Another problem with genociding is that it can increase the chances of getting more difficult, ungenocidable monsters. This is especially true for the summon nasties monster spell - summon nasties is normally restricted to a set of monsters, however if a genocided monster would be created a random monster is generated instead, based upon normal monster generation odds. If the player is carrying the Amulet of Yendor and is outside of Gehennom there is a decent chance that an Archon or Ki-rin will be generated, which are significantly more of a threat than the normal list of nasties and are capable of summoning nasties themselves.
Finally, some NetHack players abstain from genociding because they value a cursed genocide far more. In the mid-game, you can obtain bonuses from reverse-genocided monsters such as dragon scale mail, Luck increases, experience levels, attribute boosts, unicorn horns, intrinsics, and maximum hit point increases. In the late game, regular genocide is not that useful, because players are powerful or skilled enough to handle genocide candidates anyway.
A player who wishes to maintain genocideless conduct can answer "none" or "nothing" when prompted for which species to genocide.

Wizard mode genocide
Wizard mode offers an additional option for genocide: entering * for your genocide choice on a blessed scroll wipes out all enemies on the level, even those you can't see. This includes normally ungenocideable monsters, tame monsters, peaceful monsters, and everything else that isn't you. It doesn't truly genocide anything though, and anything that happened to be wiped out can still show up later. In contrast to normal genocide monsters killed in this way do NOT drop their inventory.

Variants
SLASH'EM
In SLASH'EM, titans can be genocided, as can werespiders (unlike other lycanthropes).
Good targets for SLASH'EM genocide, beyond the ones included above for vanilla, include:

High-level spellcasters: the endgame can be quite tough with them constantly summoning nasties.
V, vampire mages: higher level than a master lich but not covetous, meaning they will gladly sit outside their ring of nasties and continue summoning. Also can be created by summon nasties itself.
Z, ghoul queens: a rare monster. It has the same base level as a demilich, but it has two spellcasting attacks. Can only be found in graveyards or through the new summon undead monster spell.
G, gnoll shamans: they hide until attacked, so you can leave them alone. If awakened, they will cast both clerical and arcane spells and are absurdly high-level for both.
H, titans: they can be genocided in SLASH'EM
Mid-level spellcasters: they can curse items and tend to be fast
Z, ghoul mages: very annoying and very commonly summoned by liches with the summon undead spell
l, leprechaun wizards: like a leprechaun, they will teleport away after successfully stealing gold. Also like a leprechaun, they can be left sleeping.
n, brownies: also worth genociding, because their stealing attacks are more likely to hit than those of other nymphs, since they have a higher base level. Like nymphs though, they can be left sleeping.
Some other monsters with annoying or dangerous attacks
x, electric bugs: shock bite can explode rings and wands
a, migo queens: they eat brains but are rarer and less threatening than mind flayers
:, S, basilisks and asphynxes: both are strong and fast petrifying monsters
M, troll mummies: for those who don't like to deal with trolls' regeneration. Eating their corpses isn't a terrible idea if you have a well-enchanted unicorn horn, but pets won't eat them.
w, rot worms: they cause sickness with their bite and are often generated by summon nasties
z, koalas: they can untame any pet, making it peaceful, even if the koala itself is peaceful. This can be avoided by taming it with eucalyptus leaves.
U, water hulks: almost identical to umber hulks including the confusing gaze
Reverse genociding gypsies is a source of up to 120 wishes: use one of the summoned gypsies to wish for a magic marker, write another cursed scroll of genocide, then repeat! You do need a source of gems or gold to do this, however such items are easily found in SLASH'EM, especially from greater golems.
A careful reverse genocide of giant shoggoths is a good way to gain the teleport control intrinsic.

UnNetHack
In UnNetHack, a blessed scroll of genocide works like an uncursed one in NetHack, i.e. it allows a single monster to be genocided, rather than a monster class, and an uncursed scroll instead kills all of a single monster on the current level.

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