Quantum mechanic

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A quantum mechanic, Q, is a type of monster that appears in NetHack. It is the sole member of the quantum mechanic monster class. A quantum mechanic is a humanoid, omnivorous non-human monster that can be seen via infravision, and can teleport at random; due to being non-human, they respect Elbereth and eating one as a human character is not cannibalism.

A quantum mechanic has a single claw attack that causes its target to teleport: the teleport is subject to magic cancellation, and will fail on non-teleport levels.

Quantum mechanic corpses are poisonous to eat, and eating a quantum mechanic corpse or tin will toggle intrinsic speed - this will grant the intrinsic if you do not have it, and remove the intrinsic if you already possess it.

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.

Genetic engineers are introduced as part of the monster class.


Randomly-generated quantum mechanics are always hostile.

A quantum mechanic has a 120 chance of being generated with a large box[1] the large box has a 12 chance of generating a peaceful housecat with the name "Schroedinger's Cat" if there is room to place it on the level, and will otherwise contain a housecat corpse named "Schroedinger's Cat". The state of the cat within the box is not determined until the box is opened - see the article for more specific information.


Quantum mechanics do not hit particularly hard, but being teleported will cause you no end of annoyance: It can place you in a more disadvantageous position than you were previously, e.g. by teleporting you away from the stairs in large open areas, separating you from your pets, or else placing you next to a particularly nasty monster. If teleported out of a shop, the shopkeeper will be angered if you have any unpaid items on hand; be sure to establish credit beforehand if possible. If you are teleported by a quantum mechanic and have teleport control, you can control the destination as normal.

As a pet, the quantum mechanic has some relative use since its attack can teleport away most other monsters - there is a small chance that a pet mechanic of high enough level can attack a shopkeeper of a low enough level and teleport them out of their shop, angering them.

Quantum mechanic corpses are a useful source of speed for characters who do not yet have it - a tinned corpse is ideal if they cannot safely eat poisonous corpses. Tins of quantum mechanic are also very useful in the long term to regain lost intrinsic speed, e.g. from the attacks of a cockatrice or shade - while the same can be done with a wand of speed monster, making tins via tinning kit allows you to save their charges for pets, especially after Orcus-town. Use a stethoscope to keep track of your pets' speed and your own.

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

The potion of speed now confers intrinsic speed to characters instead of the wand, though the latter method still works for other monsters.


The quantum mechanic first appears in NetHack 1.3d. From this version to NetHack 2.3e, eating a quantum mechanic corpse confers teleportitis.

In Nethack 2.3e, quantum mechanics appear if the KAA compile-time option is defined, and are otherwise replaced by the quasit. Both monsters are included in the default bestiary for NetHack 3.0.0.


The quantum mechanic is a pun on the branch of physics known as "quantum mechanics". The messages that accompany the monster's teleporting attack and the toggling of intrinsic speed are jokes based on the Heisenberg uncertainty principle, which states that measuring the position of a particle makes its velocity more uncertain, and vice versa - some variants add YAFM that relates to this principle. Toggling the speed intrinsic could also be a reference to the transitions that occur between discrete energy levels in quantum mechanics.

"Schrödinger's cat" is a famous thought experiment in quantum mechanics involving imagining locking a cat in a box with a mechanism that has a nonzero chance of killing the cat, depending upon the final state of a quantum system; in the original thought experiment, this is a device designed to break a vial of poison if it detects the radiation emitted by a decaying atom. The orthodox Copenhagen interpretation of quantum mechanics asserts that the cat in the box is in a superposition of possible outcomes: in half of them the cat is dead, and in the other half it is alive. Only when the box is opened and "observed" is the quantum wavefunction collapsed and the fate of the cat determined - Schrödinger asserted that this was absurd, and thus so was the Copenhagen interpretation. Real-life examples of "cat states" have been experimentally demonstrated for systems larger than the subatomic scales at which quantum mechanics apply, but nowhere near the macroscopic scale of an animal; whether they can exist at such a scale is still a matter of debate among physicists.


Your position suddenly seems very uncertain!
A quantum mechanic's attack caused you to teleport.
Your velocity suddenly seems very uncertain!
You ate a quantum mechanic corpse and your intrinsic speed was toggled.
You seem slower.
Your intrinsic speed was toggled off.
You seem faster.
Your intrinsic speed was toggled on.


Some variants move the quantum mechanic to a different glyph, while others may grant them additional qualities based on quantum mechanics.


In SLASH'EM, quantum mechanics hit as a +1 weapon. This also applies to SlashTHEM.


In UnNetHack, applying a stethoscope to a quantum mechanic will cause them to teleport and print a message - this is a reference to the Heisenberg uncertainty principle as described above. This can be used to get an unwanted quantum mechanic out of your hair in a pinch.


Having determined the quantum mechanic's speed, you are unable to know its location.
You applied a stethoscope to a quantum mechanic and received a message of its status, causing it to teleport.


In xNetHack, the quantum mechanic is moved to the aberration monster class as U. Viewing a quantum mechanic via far look will give the quantum mechanic the name of a random real-life physicist (e.g., "quantum mechanic - Dr. Curie"), similar to a coyote - a cancelled quantum mechanic will have the last name on the list by default, which is "Dr. Science".


In Hack'EM, applying a stethoscope to a quantum mechanic will teleport them as in UnNetHack.

Encyclopedia entry

These creatures are not native to this universe; they seem to have strangely derived powers, and unknown motives.

 _Uncertainty Principle_ The principle that it is not possible to know with unlimited accuracy both the position and momentum of a particle. ... An explanation of the uncertainty is that in order to locate a particle exactly, an observer must be able to bounce off it a photon of radiation; this act of location itself alters the position of the particle in an unpredictable way. To locate the position accurately, photons of short wavelength would have to be used. The high momentum of such photons would cause a large effect on the position. On the other hand, using photons of lower momenta would have less effect on the particle's position, but would be less accurate because of the lower wavelength.
  [ A Concise Dictionary of Physics ]


  1. src/makemon.c in NetHack 3.6.7, line 744: this applies to the entire monster class, but the quantum mechanic is currently the sole monster