Spellbook of invisibility
|spellbook of |
|Base price||400 zm|
|Turns to read||15|
|Ink to write||20–39|
|Power cost||20 Pw|
|Equivalent||potion of invisibility|
In NetHack, the spellbook of invisibility allows you to learn the spell of invisibility. It is a level 4 escape spell, and the spellbook takes roughly 15 turns to read. It is the special spell for Rangers.
There is a ~2.54% chance that a randomly generated spellbook is a spellbook of invisibility.
There is a guaranteed spellbook of invisibility generated in a chest on the middle level of Vlad's Tower.
Casting this spell at any skill level causes you to turn invisible for 31 to 45 (more) turns.
This spell might be useful if you only want temporary invisibility so you can still enter shops later on. However, there are other sources of both temporary and permanent invisibility (e.g. via wand, ring, cloak, or potion) that are more convenient; at worst, if you are permanently invisible in a way that cannot be undone, you can still enter shops using a mummy wrapping or teleportation. Such permanent invisibility is often easier to obtain than the spell itself, and Rangers in particular are very unlikely to be able to make use of this spell before they find a mummy wrapping.
One niche use for this spell is to cast it before eating a stalker corpse to make the invisibility permanent and gain the see invisible intrinsic - but even then, other methods for this niche are more available in comparison to the spell, to say nothing of having a ring or cloak that can ideally be worn and removed at will.
Some variants focus on making the spell of invisibility more viable.
In SLASH'EM, the spell of invisibility is moved to the newly-added list of body spells (where it is still a fourth-level spell).
In dNetHack, the Windowless Tower has a spellbook of invisibility in the same place as Vlad the Impaler's original dwelling. Invisibility is also one of the spells that can take advantage of spell maintenance.
In FIQHack, invisibility is also a spell that can be maintained and kept in effect.
In xNetHack, the spellbook of invisibility is no longer randomly generated, but can still be written or wished for. It is now a level 1 escape spell, making it far easier to write and cast, and permanent invisibility is also no longer available as an intrinsic (though extrinsic sources are unchanged). This gives the spell much more of a use case compared to vanilla NetHack.
In EvilHack, the spell of invisibility is lowered to a level 3 escape spell, making it more feasible for Rangers and some other roles to utilize; this also makes the spellbook an eligible candidate for generation as part of a Wizard's starting inventory.