Spellbook of invisibility
| spellbook of + invisibility 
| |
|---|---|
| Appearance | random |
| Abundance | 2.5% |
| Base price | 400 zm |
| Weight | 50 |
| Turns to read | 15 |
| Ink to write | 20–39 |
| Spell type | escape |
| Level | 4 |
| Power cost | 20 Pw |
| Direction | non-directional |
| Equivalent | potion of invisibility |
| Special for | ranger |
In NetHack, the spellbook of invisibility can be read 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.
Contents
Generation
Spellbooks of invisibility make up 1⁄40 (2.5%) of all randomly-generated spellbooks.
A spellbook of invisibility is always generated in a chest generated within a random closet on the middle level of Vlad's Tower.[1]
Writing a spellbook of invisibility with a magic marker uses up 20 to 39 charges.
Description
Casting this spell at any skill level causes the hero to become invisible for 31 to 45 more turns.
The following information pertains to an upcoming version (NetHack 3.7.0). If this version is now released, please verify that the information below is still accurate, then update the page to incorporate it.
Per commit f83a57c5, the spell grants (6d100)+100 more turns of invisibility, the same as the effect of the hero quaffing an uncursed potion of invisibility.Strategy
Though this spell might be useful if you want temporary invisibility that does not prevent you entering shops, there are multiple 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; permanent invisibility is often easier to obtain than the spell itself, and Rangers in particular are very unlikely to make much use of this spell before they find a mummy wrapping.
One niche use for the spell is to cast it before eating a stalker corpse to make the invisibility permanent and gain the see invisible intrinsic - 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.
History
The spellbook of invisibility is introduced in NetHack 1.3d.
Variants
Some variants make the spell of invisibility more viable by lowering its level.
SLASH'EM
In SLASH'EM, the spell of invisibility is moved to the newly-added list of body spells, and is still a fourth-level spell.
dNetHack
In dNetHack, invisibility is one of the spells that can take advantage of spell maintenance.
The Windowless Tower has a spellbook of invisibility in the same place as Vlad the Impaler's tower in NetHack.
FIQHack
In FIQHack, invisibility is also a spell that can be maintained and kept in effect.
xNetHack
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.
EvilHack
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 eligible to generate as part of a Wizard's starting inventory.
