Crystal skull

(
Name	crystal skull
Appearance	crystal skull
Base price	800 zm
Weight	59
Material	glass
Monster use	May be used offensively by monsters.

A crystal skull is a type of magical tool that appears in dNetHack, notdNetHack and notnotdNetHack. It is made of glass.

Generation

Crystal skulls are not randomly generated, though they can be wished for or found in bones.

Some monsters can be generated with crystal skulls very rarely:

• A mind flayer has a ¹⁄₆₀ chance of being generated with a crystal skull if they are created in R'lyeh (the lowest floor of the Lost Cities and the Neutral Quest), a ¹⁄₃₀ chance if they are created in the future (i.e. the Anachrononaut quest and Android quest), and a ¹⁄₁₂₀ chance if they are created elsewhere.
• A master mind flayer has a ¹⁄₂₀ chance of being generated with a crystal skull if they are created in R'lyeh, which always occurs if the monster is being placed during level creation for those floors. Master mind flayers created in the future have a ¹⁄₃ chance of being generated with a crystal skull, and have a ¹⁄₉₀ chance otherwise if they are created elsewhere.
• Alhoons are always created with crystal skulls.
• The Mad Grazi is always created with a crystal skull containing Blibdoolpoolp's mindgraven champion, which will be activated immediately upon generating the Mad Grazi on the Drow Healer quest goal level.

A user has suggested improving this page or section as follows:

"Elaborate on possible crystal skull monsters."

Description

Applying a crystal skull will summon the monster and the inventory contained within it and place that monster adjacent to the user's square: this monster is treated as an ally of the crystal skull's user, so they will behave as a pet if the hero applies their crystal skull. A crystal skull's monster cannot be changed and is effectively immortal—if the summoned monster is either killed or unsummoned by some other means, such as a hero leaving the current level without the monster being able to follow, they will reappear within the skull and can be summoned again once a cooldown period has expired.

The inventory of a monster within a crystal skull is always generated each time the monster is summoned, even if the item was used up or destroyed while it was summoned previously, e.g. a crystal skull monster that is summoned carrying a potion of full healing and quaffs the potion will be generated with another one the next time they are summoned. Items that are created from the inventory of a monster summoned from a crystal skull will vanish when that monster is 'killed' or unsummoned. Applying a trephination kit to a crystal skull can be used to add up to 1000 aum worth of items to the inventory of that skull's monster or remove said items, and those changes will be applied the next time that monster is summoned.

Monsters can use this item, but only if they are some form of illithid, and hostile ones will apply them upon seeing the hero. If a copy of a crystal skull is created by summoning a monster from a crystal skull who has their own crystal skull in their inventory, that copy of the crystal skull cannot be activated by either heroes or monsters. This is done to prevent potential chain summoning from occurring if a mind flayer or master mind flayer is created with the summon nasties monster spell.

A hero cannot place trephination kits or the artifact Esscooahlipboourrr into a crystal skull, nor can they add any of the following ensouled items:

• soul wages
• soulstones
• worm gnawed skulls
• effigies
• dolls
• holy symbols of the black mother
• figurines
• statues
• magic lamps
• candles of invocation
• rings of wishes
• amulets of life saving
• misotheistic pyramids
• dimensional locks
• preservative engines
• armor salves
• living masks
• antimagic rifts
• catapsi vortexes

Strategy

For heroes seeking to snag crystal skulls, the Neutral Quest as a whole contains seven guaranteed ones: five are found in the possession of master mind flayers in R'lyeh, while the other two are obtained from defeating the two alhoons encountered within the quest.

For drow Healers, the crystal skull that the Mad Grazi is generated with will contain the quest artifact Esscooahlipboourrr as part of the inventory for Blibdoolpoolp's mindgraven champion—the Mad Grazi is also generated with a trephination kit, so the hero will always be able to retrieve it from the crystal skull, assuming they can defeat the champion and take out the Mad Grazi before he can resummon them.

Messages

You awaken the imprisoned mind!

You used a crystal skull to summon the pet inside.

The imprisoned mind is dreaming.

You tried summoning the pet while it is already summoned.

The imprisoned mind is exhausted.

You tried summoning the pet before the cooldown expired.