Extinctionism is the act of causing every possible monster in a game of NetHack to become extinct. In other words, if you kill enough monsters of one species, then that kind of monster cannot be generated anymore. A creature is extinct when 120 of its kind have been born. Once a species has become extinct, there are very few ways to create new monsters of that species. There are exceptions, however, such as pudding division, the monster spell summon nasties, etc.

How to make creatures extinct[edit | edit source]

A creature is extinct when 120 of its kind are born. The creatures do not have to be killed in order to be extinct. Once extinct, a creature will never be randomly generated again.

Therefore, you can extinct a creature simply by summoning, or reverse-genociding 120 of its kind. Killing it is optional, but highly recommended.

To extinct a creature, you must create it in a way that respects extinction.

Mechanism of monster creation can be classified in those that

  • respect extinction and increment the born counter,
  • do not respect extinction but increment the born counter,
  • neither respect extinction nor increment the born counter.

Actions that respect extinction[edit | edit source]

Actions that sometimes respect extinction[edit | edit source]

  • Throne rooms, and sitting on/confusedly looting thrones.
  • Graveyards and reading the cursed Book of the Dead.
  • Antholes.
    • If every species of ant are extinct, the random monsters that replace them will not respect extinction.
  • Shrieker summoning.
    • Purple worms will not respect extinction if explicitly rolled. If they are selected as part of a random monster roll, on the other hand, they will respect extinction.
  • Demon summoning
    • Only unique demons will respect extinction when generated by this method.
  • Spider webs
    • Spider webs generated as dungeon features will not respect extinction, and will always have a spider under them.

Actions that do not respect extinction[edit | edit source]

  • bees in a beehive (queen bees, killer bees)
  • cockatrice nests
  • leprechaun halls
  • summon nasties monster spell
  • troll regeneration
  • scroll of create monster while confused (acid blobs)
  • Division of puddings and gremlins
  • Keystone Kops summoned when you've stolen from a shop[2]
  • Quest themed monsters when replacing ordinary random monster generation in that dungeon branch

Troll regeneration, pudding/gremlin division, and some other special cases do not even increment the born counter.

Unextinctable monsters[edit | edit source]

Because the most common methods of extinctionism rely on monster generation, unique monsters are ignored by some extinctionists. However, unstoning a statue of a monster will increase the monster count for purposes of extinction; as a result, even unique monsters can be extincted in this sense. Also, monsters that leave corpses can be revived with the undead turning spell or a wand of undead turning and re-defeated. Finally, monsters that resist stoning and leave no corpse can usually wear amulets of life saving and can be extincted with enough amulets, though gathering that many amulets in a non-Wizard mode game is a task that borders on impossible.

Juiblex is the only unique monster that resists stoning, leaves no corpse and does not wear amulets (he has no head to hang them on), making him the only monster in the game that can be killed only once. If you summon him by sacrifice, he will not appear in his lair.

Keystone Kops do not become extinct even after 120 of each kind have been created.

Play styles for an extinctionist[edit | edit source]

Extinctionist wizard has filled an entire level with monsters by repeatedly casting create monster.

The easiest way to play an extinctionist is to play as a wizard. The wizard has the ability to cast create monster with no hunger penalty, and with the Eye of the Aethiopica he can cast virtually indefinitely. There is no reason another class couldn't do extinctionism; it would simply be more challenging.

Once you have the Eye, make sure to gather up all the various resistances, including magic resistance, and reflection. It would be very bad to lose your character to a random gnome with a wand of death. Make sure you have a decent set of armor, and a good weapon as well.

A common method to rack up kills is to build a boulder fort around an altar. Then stand behind the altar and cast create monster over and over, while killing the resulting monsters and sacrificing them to your god.

You can either just summon monsters and kill them at random, or try to control your summoning.

Controlling your summoning can be done by carefully regulating your own experience level, and picking which dungeon level to summon the monsters on. By keeping your experience level low, you force the game to only summon monsters of a particular difficulty or lower. In this way you can wipe out all the lower level monsters, casting and killing until create monster fails. You can then move down a dungeon level or gain an experience level to increase the monster difficulty.

Special cases[edit | edit source]

Erinyes become extinct after 3 have been created and Nazgul become extinct after 9 have been created, as would be expected based on their respective sources (although not all authors held the Erinyes to number three).

Source code references[edit | edit source]

  1. dokick.c, line 956
  2. There is code to extinct them shk.c, line 3435, but wizard mode testing confirms you can have as many Kops as you like.

External references[edit | edit source]

[extinctionism spoiler]

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