Eye or sphere

The eye or sphere is a monster class that appears in NetHack, and is represented by the lowercase e glyph (e). Eyes and spheres are designated internally by the macro S_EYE.

The class contains the following monsters:

• e gas spore
• e floating eye
• e flaming sphere
• e freezing sphere
• e shocking sphere
• Deferred monster:
  • e beholder

Common traits

Eyes and spheres are round monsters without limbs or a head that are unbreathing and capable of flight. The monster class has several traits apply to almost all of its monsters except for one or two:

• All eyes and spheres have no MR score save for the floating eye, which has a meager 10.
• All of them are mindless, except for the floating eye.
• All of them can be seen via infravision, except for the gas spore.
• Finally, all of them are neutral in alignment except for the deferred beholder.

The three spheres use explosion attacks that cause them to self-destruct and cover a 3x3 square radius centered on their position, which deals 4-24 base damage to a hero or any other monsters caught in the explosion: these explosions inflict elemental damage to the victims and can destroy vulnerable items that are in their inventories or on the ground within the explosion's range. Similarly, while gas spores do not actively attack, they explode on death in a 3x3 square centered on their tile.

Body parts

Sphere also refers to the grouping of body parts for the forms of bulbous creatures like the monsters in this monster class—this grouping is used primarily to maintain a sort of symmetry between spheres and other monsters, e.g. whenever the hero or a monster is transformed into a sphere while wearing certain items. The appropriate body parts are referred to as follows:

Bodypart	Description
Arm	Appendage
Eye	Optic nerve (cornea for floating eyes)
Face	Body
Finger	Tentacle
Fingertip	Tentacle tip
Foot	Lower appendage
Hand	Tentacle
Handed	Tentacled
Head	Body
Leg	Lower tentacle
Light Headed	Rotational
Neck	Equator
Spine	Body
Toe	Lower tentacle tip
Hair	Cilia
Blood	Life force
Lung	Retina
Nose	Olfactory nerve
Stomach	Interior

Despite a lack of proper "limbs" to wield anything or wear items with, a hero in the form of any monster with sphere anatomy can still perform actions such as quaffing, reading, zapping, and applying objects; though putting on items is restricted to amulets, rings that the hero wore in their previous form will remain worn if they turn into a spherical monster. In particular, this means that floating eyes are technically capable of using the defensive items that they generate with as intelligent monsters, though in practice a floating eye other than the hero will not quaff, read or zap anything.

Generation

Randomly generated eyes and spheres are always hostile.

Strategy

The gas sphere and floating eye are two of the bigger threats for an inattentive hero in the early game: the former can blast a weaker hero to death if the explosion deals enough damage, while a hero frozen by the floating eye's paralyzing passive gaze has a high risk of dying at the hands of any nearby hostile or even as a result of starvation if they are paralyzed long enough. Once a hero obtains enough HP and a blindfold or other means of blinding themselves at will, gas spores and floating eyes are annoyances at best, though the latter can still catch even late-game players off guard if they move too quickly and lack a source of free action or reflection.

The elemental spheres are quite annoying due to their 13 speed being slightly higher than that of a normal hero, as well as the destructive potential of their explosions, but there are several means to deal with them: they have no MR score and so can be put to sleep or otherwise immobilized, with the former option preferable for a hero low on resources; poisoned weapons can make short work of them as well; and stronger pets can be used to attack spheres and cause them to explode before reaching the hero, though they may still end up caught in the resulting explosions and wake up sleeping monsters or waking nearby ones. Cancellation that hits through their mediocre 4 AC will reliably disable their explosive abilities and render them harmless.

More cautious or risk-averse players may consider targeting one or more spheres for genocide, with shocking spheres being a particularly frequent target since their explosions can destroy valuable rings and wands. A hero that has a source of an extrinsic resistance property has a ⁹⁹⁄₁₀₀ chance per item of preventing a sphere's explosion from destroying inventory, and in a pinch against flaming and freezing spheres they can quickly throw on a spare dwarvish cloak to have a ⁹⁄₁₀ chance of protecting their inventory.

Be sure to keep gas spores and spheres away from leprechaun halls, treasure zoos and similar rooms of monsters that you do not want awakened if possible, and if any of them are generated within zoos, try to save them for last if at all possible—stealth can be a useful aid for both purposes, though it will not always prevent sleeping monsters from awakening.

History

The floating eye and freezing sphere appear in Hack for PDP-11, which is based on Jay Fenlason's Hack, and is included in the initial bestiary for Hack 1.0—in Hack 1.21, the evil eye (not to be confused with the evil eye from variants of NetHack) and ice ball are somewhat similar monsters included in the bestiary.

NetHack 3.0.0 introduces the eye or sphere monster class and moves the floating eye and freezing sphere to their current glyphs. The flaming sphere first appears in NetHack-- 3.0.10, while the shocking sphere and gas spore appear in SLASH 6, and all three make their vanilla NetHack debut in NetHack 3.3.0.

In versions up to NetHack 3.4.3, flaming and shocking spheres are capable of picking up items—this is bug C343-138, and is fixed via commit cbab68a4.

In versions up to NetHack 3.6.7, including some variants based on those versions, the explosion attacks of elemental spheres target a single monster (or the square are believed to occupy if the target is invisible or has displacement): these explosions can miss and have no effect if directed at the wrong square, and the hero can also "duck" these explosions and take reduced damage based on their dexterity, while a hero or monster blasted this way will take no damage at all if they have the appropriate resistance property. The current behavior of spheres is introduced in NetHack 5.0.0 via commit 6b60618e and commit eb22a810, with the explosion behavior adapted from xNetHack.

Variants

Many NetHack variants make the deferred beholder functional as part of adding new monsters to the monster class, and some variants created prior to NetHack 5.0.0 may or may not retain the behavior of spheres from previous versions.

SLASH'EM

SLASH'EM implements the Beholder as the boss of the Neutral Quest and adds two other monsters to the monster class:

• e bloodshot eye
• e blinking eye
• e Beholder

The spheres mostly behave as they do in NetHack 3.4.3.

GruntHack

GruntHack implements the beholder and gives it significant buffs, while retaining all other monsters from NetHack 3.4.3. The spheres mostly behave as they do in NetHack 3.4.3.

UnNetHack

UnNetHack adds several monsters to the monster class:

• e evil eye
• e dungeon fern spore
• e arctic fern spore
• e blazing fern spore
• e swamp fern spore
• e fern spore

Floating eyes use the same glyph with a different color: e

dNetHack

dNetHack implements the beholder and changes it significantly, and adds many other monsters to the monster class:

• e monoton
• e duton
• e triton
• e quaton
• e quinon
• e ballistospore
• e sphere of force
• e pursuer
• e vexing orb
• e flaming orb
• e beholder
• e ball of light
• e eye of doom
• e ball of radiance
• e aphanactonan audient
• e aphanactonan assessor
• e bloody sunset
• e ball of gossamer sunlight
• e eternal light
• e dungeon fern spore
• e swamp fern spore
• e burning fern spore
• e Moon-entity eye-cluster
• e many-eyed seeker
• e Axus

notdNetHack

notdNetHack and notnotdNetHack retain the monsters added in dNetHack and adds two other monsters to the monster class:

• e Death Eye
• e Great Mother