Crystal ball

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( Crystal ball.png
Name crystal ball
Appearance glass orb
Base price 60 zm
Weight 150
Material glass
Monster use Will not be used by monsters.

The crystal ball is a magical tool that appears in NetHack. It is made of glass, and appears as a glass orb when unidentified.

The Orb of Fate and Orb of Detection are artifact crystal balls, as is the defunct Palantir of Westernesse.


A randomly generated crystal ball is normally generated with 1-5 charges and has a 25% chance of being blessed, a 50% chance of being uncursed, and a 25% chance of being cursed.[1]

Elvenkings have a 2% chance of being generated with a crystal ball.[2]

The fourth variant of Medusa's Island will always generate a crystal ball underwater in the kraken's dwelling, on the square just outside the door leading to it.[3]


Applying or #invoking a charged crystal ball while not blind will initiate an Intelligence check - if the result of a d20 is less than or equal to your Intelligence, the check succeeds and can then search for a symbol on the current level, consuming a charge.[4][5] A cursed crystal ball will always fail the check when used, and a failed check will produce on of the following effects:

  • No further effect.
  • You are confused for d100 turns.
  • You are blinded for d100 turns.
  • You hallucinate for d100 turns.
  • The ball explodes, destroying it and dealing d30 damage. This is affected by half physical damage, and artifact crystal balls will not break this way.

Applying a crystal ball will always put you into a helpless trance for 1 to 10 turns - a ring of free action will not prevent this. Applying a crystal ball with no charges will always reveal nothing, but does not risk negative effects.

On a successful check, you can specify any symbol representing a monster, object or trap. If you try to search for anything else, such as stairs or other dungeon features, you will instead receive a message hinting at the location of a special level: Delphi, Medusa's lair, the castle, or the Wizard of Yendor's tower chosen at random.[6][7][8] The message you receive depends on whether you are in the same dungeon branch as the target level and its dungeon level relative to yours: "You see <foo>, <where>."[9] The exact message and location <where> is determined based on the information in the following table:

Dlvl difference Message (in the same branch) Message (not in the same branch)
greater than 8-10[10] "far below/above" "far away"
greater than 1 but no greater than the above number "below/above you" "away below/above you"
1 "just below/above" "in the distance"
0 "near you" "in the distance"[11]

Attempting to use a crystal ball while blind will fail with no chance of negative effects, and does not consuming a charge. Using a crystal ball while hallucinating still activates the Intelligence check, but if you pass you will simply be given a useless message; failure still has the usual consequences.

Reading an uncursed scroll of charging and selecting a crystal ball will add one charge, up to a maximum of 5, while a blessed scroll will set the crystal ball to 6 charges instead.

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.

You can now search for dungeon features by entering any of < > _ \ # { - doing so will find all of these features regardless of which one you entered.

The intelligence check when applying a crystal ball now uses a d8 instead of d20 if it is your own quest artifact, or d16 for other blessed crystal balls.

Crystal balls are now generated with 3-7 charges. Uncursed charging adds 1-2 charges up to the maximum of 7. Blessed charging increases the number of charges to 7 and also blesses the ball. Cursed charging removes all charges and curses the ball.

Applying a cancelled crystal ball now destroys it, regardless of whether or not it is an artifact.


The crystal ball is characterized by its shortcomings at least as much as its strengths - it is quite heavy, and successful use makes the player helpless for a period of time. Even with 18 Intelligence there is a non-trivial 10% chance of failure, and only elves can raise the stat to 20 naturally without aid from a helm of brilliance. If it does work, it only allows the user to search for a single class of monster or object, whereas most searching items are completely reliable, non-incapacitating, and will reveal all monsters or objects on a level.

Generally, do not use a crystal ball if you are in a position where you could be attacked in the next 10 turns, have less than 31 HP, or lack a quick cure for impairments - failure can prove deadly, especially for low-level characters. Non-artifact crystal balls can also easily shatter and so should be handled with care - especially if you are carrying one in open inventory or within a non-magical container, and if you are punished in particular.[12]

That said, the crystal ball can still be used effectively beyond polyfodder for a magic marker. The most relevant of these uses is for finding the vibrating square or portal detection. Though reading a scroll of gold detection while confused is usually preferable and takes much lighter resources, crystal balls may be more ideal for conduct players (e.g., illiterate and/or pacifist) or very cautious players that do not know the scroll of gold detection or other means of object detection. In addition to use on the Elemental Planes, it can also be used to detect traps or else search for vaults to clear them out and/or find the magic portal to Fort Ludios.

Tourists are in a somewhat unique position to employ a crystal ball - The Platinum Yendorian Express Card grants almost unlimited access to charging, and crystal balls do not explode from overcharging.

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.

As the intelligence check for your own quest artifact crystal ball uses a d8, Valkyries and Archeologists can reliably use their quest artifacts to find the vibrating square and/or spot magic portals on the Planes. A blessed crystal ball can also be reliably used with a minimum of 16 intelligence, making them much easier for non-elves to apply.


The crystal ball is introduced in NetHack 3.0.0.


The crystal ball is typically associated with the art of scrying (known in this form as "crystal gazing" or "crystallomancy"), with a history of such going back to the writings of Pliny the Elder in the 1st century CE; crystal gazing was a particular popular pastime in the Victorian era as well. The crystal ball served as a medium through which thoughts were focused, with the intent of detecting significant messages or visions for various purposes: personal guidance, prophecy, revelation, inspiration, or even divination and fortune-telling.

The small chance that Elvenkings will be generated with a crystal ball is based on the palantír, a fictional magical artifact from J. R. R. Tolkien's Middle-earth novels that appears as an indestructible ball of crystal, and is used for communicating and viewing the past and future. This serves as the inspiration for the Palantir of Westernesse, as well as for the fact that only elven player characters can naturally reach the required Intelligence stat to use crystal balls without a chance of failure.

The crystal ball in Medusa's domain may be an allusion to the Graeae - three daughters of the sea-deities Phorcys and Ceto and sisters to the Gorgons. The Graeae shared a single eye and tooth; Perseus stole their shared eye in order to ransom it for information on the whereabouts of either Medusa herself or the three objects needed to slay her.


You may look for an object or monster symbol.
You successfully peered into a crystal ball, and may select a symbol to search for.
Too bad you can't see the crystal ball.
You applied a crystal ball while blind.
The vision is unclear.
You applied a crystal ball without any charges, or else successfully peered into one but did not reveal anything.
You see the Wizard of Yendor gazing out at you.
This is a joke message that has a 1% chance of occurring on a successful peer that does not reveal anything; the purpose is explicitly to try and make players nervous.[13]
Whoa! Psychedelic colors, <dude/babe>!
All you see is funky <color> haze.
You grok some groovy globs of incandescent lava.
The crystal pulses with sinister <color> light!
You see goldfish swimming above fluorescent rocks.
Oh wow... like a kaleidoscope!
You see tiny snowflakes spinning around a miniature farmhouse.
You "successfully" peered into a crystal ball while hallucinating.



In SLASH'EM, crystal balls are notably the only tool not affected by the amnesia-inducing waters of the Castle's moat.

SLASH'EM's precursors, NetHack Plus and SLASH 6, introduce additional orbs - the orb of charging, orb of destruction and orb of enchantment - that share the same appearance as the crystal ball. These glass orbs had a base price of 750 zm and weigh 75 aum, making it somewhat easy to tell an actual crystal ball apart from them via weight testing or price identification. These orbs remain in the code of SLASH'EM as deferred feature.[14][15]

NetHack brass

NetHack brass adds the glass orbs from NetHack Plus and SLASH 6, but replaces the orb of destruction with the orb of maintenance. Additionally, the crystal ball now weighs 75 aum like the other glass orbs, meaning that price identification is the most reliable method to informally identify a glass orb.


In EvilHack, a crystal ball is one of the few ways to see the object type of the Sokoban prizes behind each door and potentially determine their identity.


In xNetHack, crystal balls start with d25 charges and weigh only 100 aum. Gazing into them no longer paralyzes you, and a blessed or cursed ball counts as +5 or −5 toward the intelligence check - they will never explode unless cursed. Entering an invalid character to search for in a crystal ball will prompt you again rather than wasting the charge. Uncursed charging of a crystal ball will add (d5)+5 charges.

One of Itlachiayaque's invocation effects allows the holder to gaze into it for the same effect as a crystal ball of the same beatitude, akin to the vanilla Orb of Detection that it replaces.

Encyclopedia entry

You look into one of these and see _vapours swirling like
clouds_. These shortly clear away to show a sort of video
without sound of something that is going to happen to you
soon. It is seldom good news.
[ The Tough Guide to Fantasyland, by Diana Wynne Jones ]