There are two types of spell books, standard ones with a set name and list of spells and randomly generated (randart) books that contain multiple random, but often thematically linked, spells.
Besides finding them on the dungeon floor or shops, spell books can be obtained by using acquirement or gifted by Sif Muna or Kikubaaqudgha. Mage and warrior-mage backgrounds get a starting book and Wanderers sometimes get one as well.
Spell books are identified automatically once player steps on the square where the book is located.
Followers of Trog have the ability to burn spell books on the floor to produce clouds of flame.
Spell books are not exactly rare, but there are so many different ones out there that finding a specific spell book may be difficult or even impossible in a given game. While book shops provide a large, random assortment to choose from, spell books are also generally rather expensive. Thus, obtaining a specific spell book that you want can be a hassle, but you can alleviate this by worshiping the right god.
Sif Muna and Kikubaaqudgha both grant spell books as gifts. Sif Muna is the most generous in this regard: since the types of spell books granted depend on magical skills, you can influence them by training specific skills, and thus raise your probability of getting the most useful spells for your play-style. Followers of Sif Muna will eventually have access to every spell in the game this way. Meanwhile, Kikubaaqudgha only grants Necromancy-related books (including the Necronomicon at the final piety level). It is also worth noting that Kikubaaqudgha starts granting his books sooner than Sif Muna. Vehumet doesn't gift spell books, but instead offers Conjuration spells directly.
Note that you keep your gift books even if you abandon your god. Some advanced players take advantage of this, serving Kikubaaqudgha until they get the Necronomicon (and can survive divine retribution), then leaving for another god who offers further powers.
- See also: List of spells by book
- Book of Air: Shock, Swiftness, Static Discharge, Airstrike, Lightning Bolt
- Book of Alchemy: Sublimation of Blood, Ignite Poison, Petrify, Alistair's Intoxication, Irradiate
- Book of Annihilations: Poison Arrow, Chain Lightning, Lehudib's Crystal Spear, Glaciate, Fire Storm
- Book of Battle: Infusion, Shroud of Golubria, Song of Slaying, Spectral Weapon, Regeneration
- Book of Beasts: Summon Butterflies, Call Canine Familiar, Summon Ice Beast, Summon Mana Viper, Summon Hydra
- Book of Burglary: Swiftness, Passwall, Passage of Golubria, Lee's Rapid Deconstruction, Darkness, Invisibility
- Book of Callings: Summon Small Mammal, Call Imp, Call Canine Familiar, Summon Guardian Golem, Summon Lightning Spire, Summon Ice Beast
- Book of Cantrips: Confusing Touch, Animate Skeleton, Summon Small Mammal, Apportation
- Book of Changes: Beastly Appendage, Sticks to Snakes, Spider Form, Ice Form, Blade Hands
- Book of Clouds: Mephitic Cloud, Conjure Flame, Poisonous Cloud, Freezing Cloud, Ring of Flames
- Book of Conjurations: Magic Dart, Searing Ray, Dazzling Spray, Fulminant Prism, Iskenderun's Mystic Blast, Iskenderun's Battlesphere
- Book of Death: Corpse Rot, Sublimation of Blood, Agony, Dispel Undead, Excruciating Wounds, Bolt of Draining
- Book of Debilitation: Corona, Slow, Inner Flame, Portal Projectile, Cause Fear, Leda's Liquefaction
- Book of Dreams: Ensorcelled Hibernation, Silence, Darkness, Shadow Creatures
- Book of the Earth: Leda's Liquefaction, Bolt of Magma, Statue Form, Iron Shot, Shatter
- Book of Enchantments: Cause Fear, Yara's Violent Unravelling, Silence, Deflect Missiles, Discord
- Book of Fire: Ignite Poison, Fireball, Bolt of Fire, Delayed Fireball, Ring of Flames
- Book of Flames: Flame Tongue, Throw Flame, Conjure Flame, Inner Flame, Sticky Flame, Fireball
- Book of Frost: Freeze, Throw Frost, Ozocubu's Armour, Throw Icicle, Summon Ice Beast
- Book of Geomancy: Sandblast, Passwall, Stone Arrow, Petrify, Lee's Rapid Deconstruction
- Book of Ice: Ice Form, Metabolic Englaciation, Ozocubu's Refrigeration, Bolt of Cold, Freezing Cloud, Simulacrum
- Book of Maledictions: Corona, Ensorcelled Hibernation, Confuse, Tukima's Dance, Dazzling Spray
- Book of Minor Magic: Magic Dart, Blink, Call Imp, Repel Missiles, Slow, Conjure Flame, Mephitic Cloud
- Book of Necromancy: Pain, Animate Skeleton, Vampiric Draining, Regeneration, Animate Dead, Control Undead
- Book of Party Tricks: Summon Butterflies, Apportation, Lesser Beckoning, Tukima's Dance, Alistair's Intoxication, Invisibility
- Book of Power: Fulminant Prism, Iskenderun's Mystic Blast, Venom Bolt, Bolt of Magma, Iron Shot, Orb of Destruction, Spellforged Servitor
- Book of Spatial Translocations: Blink, Shroud of Golubria, Lesser Beckoning, Gell's Gravitas, Teleport Other, Passage of Golubria
- Book of Summonings: Recall, Aura of Abjuration, Summon Demon, Summon Forest, Summon Mana Viper, Shadow Creatures
- Book of the Dragon: Flame Tongue, Cause Fear, Bolt of Fire, Dragon Form, Dragon's Call
- Book of the Sky: Summon Lightning Spire, Airstrike, Silence, Deflect Missiles, Conjure Ball Lightning, Tornado
- Book of the Tempests: Static Discharge, Lightning Bolt, Fireball, Tornado, Shatter
- Book of the Warp: Gell's Gravitas, Portal Projectile, Force Lance, Dispersal, Controlled Blink, Disjunction
- Book of Transfigurations: Irradiate, Statue Form, Hydra Form, Dragon Form
- Book of Unlife: Recall, Animate Dead, Control Undead, Cigotuvi's Embrace, Death Channel, Simulacrum
- Fen Folio: Corpse Rot, Stone Arrow, Leda's Liquefaction, Summon Forest, Hydra Form, Summon Hydra
- Grand Grimoire: Monstrous Menagerie, Summon Greater Demon, Malign Gateway, Summon Horrible Things
- Necronomicon: Haunt, Borgnjor's Revivification, Death's Door, Infestation, Necromutation
- Young Poisoner's Handbook: Sting, Mephitic Cloud, Olgreb's Toxic Radiance, Alistair's Intoxication, Venom Bolt
- Removed book: Book of Control
- High level spell books no longer restrict learning from them based on skill levels
- Removed book: Book of War Chants
- Added books: Book of Battle