# Spellbook

Item classes

"&nbsp;Amulets

[&nbsp;Armor

%&nbsp;Comestibles

$&nbsp;Coins

*&nbsp;Gems

!&nbsp;Potions

=&nbsp;Rings

?&nbsp;Scrolls

+&nbsp;Spellbooks

`&nbsp;Statues

(&nbsp;Tools

`&nbsp;Boulders

)&nbsp;Weapons

/&nbsp;Wands

A spellbook, +, is a type of book that appears in NetHack and contains runes describing a spell. You learn the spell by reading the spellbook with r and attempting to memorize it; if you have a blank spellbook and a magic marker, you can also attempt to write your own copy of any known spellbook in the game (see Magic_marker#Writing_success_chance). Both actions obviously break the illiterate conduct.
In tty mode, both brown books and closed doors share the + symbol.
Spellbooks have a weight of 50 aum, and the base price of a spellbook is 100zm per level.

Contents

1 Description
2 List of spellbooks

2.1 Attack
2.2 Clerical
2.3 Divination
2.4 Enchantment
2.5 Escape
2.6 Healing
2.7 Matter
2.8 Other

3 Success rate of reading

3.1 Failure effects of spellbook reading

4 Strategy

4.1 Learning spells
4.2 Safely reading non-blessed spellbooks
4.3 Carrying spellbooks
4.4 Cursed spellbooks

5 History
6 Messages
7 Variants

7.1 SLASH'EM
7.2 UnNetHack
7.3 FIQHack

8 Encyclopedia entry
9 See also
10 References

Description
The odds of you learning a spell from reading the spellbook are dependent on the level of its spell and the book's beatitude; if the spellbook is cursed, or else uncursed and too difficult, you will not learn the spell, but suffer harmful effects instead. A blessed spellbook will always be read successfully; a pair of lenses increases the chance of successfully reading an uncursed spellbook by 10 percentage points, and reduces the amount of actions needed to read the book by about one-third.
Attempting to read a spellbook with the randomized appearance of a "dull spellbook" may cause you to fall asleep for a number of turns, based on your Wisdom and the spellbook's level; sleep resistance prevents this effect.
Spellbooks cannot be read while blind. Attempting to read a spellbook while confused will always fail, and has a 1⁄3 chance to destroy the spellbook.[1]
Reading an unpaid-for spellbook in a shop while in the presence of the shopkeeper incurs a usage fee. ("This is no free library, cad!")
After successfully learning a spell from a spellbook, you will retain memory of that spell for 20,000 turns afterward, and the 'read' counter for that spellbook is incremented by one. A spellbook that has been 'read' three times will fade after refreshing the spell from it, making spell and book management quite important.[2][3] Re-reading a spellbook "early" – i.e., while you still know the spell and are more than 2,000 turns from forgetting it – has no effect beyond exercising wisdom.[4] If you polymorph a spellbook, it will increment the 'read' counter by one.
Roles that start with spellbooks in their initial inventory will begin the game already knowing the pertinent spell(s); the books themselves are always treated as brand-new.[5]
Dipping a spellbook into water (or a fountain) will blank it; spellbooks made blank this way will retain their beatitude.

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 apply a spellbook to flip through the pages and appraise how fresh it is; per commit b55165e, this was adapted from UnNetHack. See the Messages section below.
List of spellbooks
The following is a list of all spellbooks, listed alphabetically by the school of magic they represent and ordered by difficulty within the schools.
Directional spells behave just like zapping a wand, with the same range.
The "Probability conditional on price" column is for use with price identification. If you know the price of the book, this column tells you how likely it is to be a given spell. (For instance, a spellbook with a base price of 700 zm is 75% likely to be cancellation, and 25% likely to be finger of death.)
The "Actions to read" column tells you how many player actions are needed to read the spellbook. This is equal to the number of game turns for a hero whose speed is 12; a faster hero will take fewer turns to read the book. Lenses reduce this number of actions by approximately one third.
The "Skill changes" column denotes spells that behave differently if the player has a higher skill level in that spell's school.  "B" indicates that the spell behaves differently at a skill level of basic or greater, "S" indicates that the spell behaves differently at skilled or greater, and "E" indicates that the spell behaves differently at expert.  Note that most ray spells have a higher hit chance when cast at a higher level.

Attack

Spellbook
Spell level
Direction
Relative probability
Probability conditional on price
Actions to read
Skill changes

Spellbook of force bolt
1
beam
3.56%
12.2%
4

Spellbook of drain life
2
beam
1.01%
4.3%
4

Spellbook of magic missile
2
ray
4.58%
19.1%
4

Spellbook of cone of cold
4
ray (distant if skilled)
1.01%
8.3%
23
S

Spellbook of fireball
4
ray (distant if skilled)
2.03%
16.7%
14
S

Spellbook of finger of death
7
ray
0.5%
25.0%
82

Clerical

Spellbook
Spell level
Direction
Relative probability
Probability conditional on price
Actions to read
Skill changes

Spellbook of protection
1
non-directional
1.83%
6.3%
5
E

Spellbook of create monster
2
non-directional
3.56%
14.9%
5

Spellbook of remove curse
3
non-directional
2.54%
10.8%
12
S

Spellbook of create familiar
6
non-directional
1.01%
19.6%
44

Spellbook of turn undead
6
beam
1.62%
31.4%
50

Divination

Spellbook
Spell level
Direction
Relative probability
Probability conditional on price
Actions to read
Skill changes

Spellbook of detect monsters
1
non-directional
4.37%
15.0%
3
S

Spellbook of light
1
non-directional
4.58%
15.7%
3

Spellbook of detect food
2
non-directional
3.05%
12.8%
5
S

Spellbook of clairvoyance
3
non-directional
1.52%
16.5%
8
S

Spellbook of detect unseen
3
non-directional
2.03%
8.6%
10

Spellbook of identify
3
non-directional
2.03%
8.6%
14
S

Spellbook of detect treasure
4
non-directional
2.03%
16.7%
17
S

Spellbook of magic mapping
5
non-directional
1.83%
47.4%
37

Enchantment

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.

Some enchantment spell levels have changed: sleep is level 3, confuse monster is level 1, and charm monster is level 5.

Spellbook
Spell level
Direction
Relative probability
Probability conditional on price
Actions to read
Skill changes

Spellbook of sleep
1
ray
5.09%
17.5%
3

Spellbook of confuse monster
2
non-directional
3.05%
12.8%
4
S

Spellbook of slow monster
2
beam
3.05%
12.8%
4

Spellbook of cause fear
3
non-directional
2.54%
10.8%
8

Spellbook of charm monster
3
non-directional
2.03%
8.6%
8

Escape

Spellbook
Spell level
Direction
Relative probability
Probability conditional on price
Actions to read
Skill changes

Spellbook of jumping
1
non-directional
2.03%
7.0%
5
BSE

Spellbook of haste self
3
non-directional
3.36%
14.2%
10
S

Spellbook of invisibility
4
non-directional
2.54%
20.8%
17

Spellbook of levitation
4
non-directional
2.03%
16.7%
14
S

Spellbook of teleport away
6
beam
1.52%
29.4%
38

Healing

Spellbook
Spell level
Direction
Relative probability
Probability conditional on price
Actions to read
Skill changes

Spellbook of healing
1
beam
4.07%
14.0%
4
S

Spellbook of cure blindness
2
non-directional
2.54%
10.6%
4

Spellbook of cure sickness
3
non-directional
3.25%
13.8%
8

Spellbook of extra healing
3
beam
2.74%
11.6%
12

Spellbook of stone to flesh
3
beam
1.52%
6.5%
4

Spellbook of restore ability
4
non-directional
2.54%
20.8%
17
S

Matter

Spellbook
Spell level
Direction
Relative probability
Probability conditional on price
Actions to read
Skill changes

Spellbook of knock
1
beam
3.56%
12.2%
3

Spellbook of wizard lock
2
beam
3.05%
12.8%
5

Spellbook of dig
5
ray
2.03%
52.6%
32

Spellbook of polymorph
6
beam
1.01%
19.6%
50

Spellbook of cancellation
7
beam
1.52%
75.0%
66

Other
Spellbook of blank paper—"plain spellbook", 1.83% relative probability
Book of the Dead—"papyrus spellbook", unique item
Novel—"paperback book", Terry Pratchett tribute.
Success rate of reading
The probability of successfully reading an uncursed book is:[6]

A hypothetical level 0 character needs 16 INT to read a hypothetical level 0 spellbook safely. For every spell level, increase the required INT by two. For every two experience levels (odd ones count as the level below), decrease it by one. If wearing lenses, decrease it by two. 
A Wizard will be warned when reading an uncursed spellbook if this chance is below 100%, with a slightly different messages if the chance is below 60%; a cursed spellbook will never prompt a warning.
The numbers are tabulated in the NetHack Spellbook Reading Spoiler.

Failure effects of spellbook reading
Failing to read a spellbook (or reading a cursed spellbook) paralyses the player for a number of turns equal to the number of player actions needed to read the book minus two. Thus, the minimum duration of the paralysis is one turn (detect monsters, light, sleep, knock) and the maximum duration is 80 turns (finger of death). A ring of free action will not protect the player from this effect.
A random effect is chosen in addition to the paralysis, with the list below numbered to match the minimum spellbook level needed for that effect to occur:[7][8]

You are teleported to somewhere else on the level; this takes effect immediately, with paralysis applied after.
All monsters on the level are woken up and unparalysed.
You are blinded for 250–349 turns.
All your visible gold vanishes.
You are confused for 16–22 turns.
You lose 1–10 HP and 3–6 strength (1-6 HP and 1–2 strength if poison resistant); gloves protect you from this effect, though gauntlets of power will corrode in the process.
The book explodes, dealing 7–25 points of damage unless you have magic resistance and destroying itself.
There is a 1⁄3 chance of the spellbook crumbling to dust for each failed reading, assuming that the book has not exploded. You will then be prompted to name the spellbook if it was not identified or already type named.

Strategy
Learning spells
Do not attempt to read a spellbook unless you have tested or identified its beatitude, and you are certain it isn't cursed. Unless you are a Wizard, do not attempt to read a non-blessed spellbook unless you know which level it is; this can be easily determined via price identification at the appropriate shop.
Whenever you successfully read a spellbook:

Type-name it with the current turn number, so that you will know when you need to rememorize it. You can review the type-names of identified items with the \ key.
Individual-name it '1', or increment the existing number, so you know how many times you have read it.
When studying a forgotten spell, read the book again immediately afterwards to make sure it won't turn blank (and fail to refresh the spell) the next time you need to read it - as noted above, if the spellbook is still viable, nothing bad will happen to it.

Safely reading non-blessed spellbooks
In practice, the biggest dangers when reading non-blessed spellbooks are losing the book and getting teleported to a random location on the level while paralysed. Teleport control allows you to choose where you will teleport, rendering this effect mostly harmless. A unicorn horn will cure blindness, confusion and strength loss; wearing gloves will prevent strength loss and damage from poison in the first place, while blindness and confusion will wear off eventually. Bagging your gold when reading spellbooks will prevent it from being lost, and magic resistance will protect you from the damage inflicted by a book exploding.
Reading such spellbooks while carrying unpaid goods in shops is especially perilous - if you are teleported, the shopkeeper will become angry and call the Keystone Kops while you are paralyzed.
You can read spellbooks of up to level 5 in relative safety if you have teleport control, lock yourself in a closet with Elbereth engraved on the floor and drop your gold. To safely read level 6 and higher spellbooks, you also need gloves and/or a unicorn horn and, for level 7 books, magic resistance or at least 26 HP. If you don't have teleport control, you can instead read them on a non-teleport level, such as inside the closets on the top level of Sokoban.

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.

Unicorn horns can no longer restore reduced attributes. Alternatives include potions of restore ability, the restore ability spell, prayer, or the potion of gain ability.
Carrying spellbooks
Roles that start with spellbooks will probably want to stash them at the first opportunity, both to reduce encumbrance and to avoid losing them to sources of fire. Selling them to a shop, if you can find one that takes them, is a useful source of extra gold in the early game; by the time you need your books back on turn 20,000, you should easily be able to afford them.
If you have a 1⁄3 or higher net markup on your buying price (which is likely the case for an early-game character), reading a shop-owned book unbought and paying the usage fee is cheaper than buying the book, then reselling it after reading.

Cursed spellbooks
Occasionally, if you have teleport control, don't need the book, and power is at a premium, you might want to (write and) read cursed spellbooks of detect monsters, light, sleep, or knock for their teleport effect since these books will paralyze you only for one turn and are cheap to write. The guaranteed teleport effect may be useful as an escape if other resources for this are scarce. A speed runner might even write cursed books to conserve power and scrolls of charging.

History
Spellbooks are introduced in NetHack 1.3d.
In NetHack 3.4.3, you can only read a spellbook to refresh memory of that spell with 1,000 turns of memory or less left. Additionally, due to a bug, a polymorphed spellbook would never fade if the spell was not already in your spellcasting menu Z, allowing you to read it once to learn the spell, which you could then rewrite with a magic marker for future reference. This was fixed in NetHack 3.6.0.[9]
NetHack 3.6.0 increases the turn threshold for refreshing spell knowledge from 1,000 to 2,000. The additional effect of dull spellbooks was also introduced in 3.6.0; in this version, it ignores sleep resistance. This was changed in NetHack 3.6.1.

Messages
This book is so dull that you can't keep your (eyes) open.
You attempted to read a dull spellbook, and do not have sleep resistance. You do not learn the spell, but are not subjected to the other failure effects.
This spellbook is 

<very> difficult to comprehend. Continue?
You are a Wizard, and were given a prompt to continue reading a spellbook that you do not have a 100% chance of learning the spell from; "very" is appended if the chance is below 60%.
You feel a wrenching sensation.You feel threatened.A cloud of darkness falls upon you.You notice you have no money!These runes were just too much to comprehend.
You failed to learn a spell from reading its spellbook, and are subjected to a detrimental effect based on its level, including the next two listed.
The book was coated with contact poison!
As above; you lose d10 HP and 3d2 strength, lowered to d6 HP and d2 strength if poison resistant.
As you read the book, it radiates explosive energy in your <face>!
As above; this effect destroys the book and inflicts 7-25 points of damage.
The book radiates explosive energy, but you are unharmed!
You triggered the above effect, but are magic resistant.
Being confused you have difficulties in controlling your actions.
You attempted to read a spellbook while confused; this will always fail and lead to one of the following two messages:
You accidentally tear the spellbook to pieces.
The spellbook is destroyed; this has a 1⁄3 chance to occur.
You find yourself reading the [first/next] line over and over again.
Nothing else happens.

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.

The [magical] ink in this spellbook is fresh.
You are flipping through a spellbook that has been affected 0 times.
The [magical] ink in this spellbook is slightly faded.
You are flipping through a spellbook that has been affected 1 time.
The [magical] ink in this spellbook is very faded.
You are flipping through a spellbook that has been affected 2 times.
The [magical] ink in this spellbook is extremely faded.
You are flipping through a spellbook that has been affected 3 times. It can no longer be used to learn a new spell.
The [magical] ink in this spellbook is barely visible.
You are flipping through a spellbook that has been affected 4 times. It can no longer be studied at all.
You hear the pages make an unpleasant rustling sound.
You are flipping through the Book of the Dead.
You see the pages glow faintly red.
You are flipping through the Book of the Dead while deaf.

Variants
SLASH'EM
Spellbooks have charges now.  When reading a non-cursed charged spellbook, one charge is consumed, and "The words on the page seem to glow faintly." This allows you to read the spelbook normally should you fail the reading roll, and triples the reading speed otherwise.

UnNetHack
In UnNetHack as of version 4, you can apply spellbooks to receive an indication of how many more times they can be read.[10]

FIQHack
FIQHack has numerous changes regarding spellbooks:

Monsters can learn spells from spellbooks.
When you successfully read a spellbook, you retain the spell for 60k turns instead of 20k.
Successfully reading a spellbook destroys it.
You never start with spells memorized, but will always start with the equivalent spellbooks.
The spellbook of haste self is now the spellbook of speed monster; the accompanying spell works the same, but can additionally be cast at other monsters.
Spellbook weight is tied to level: Blank spellbooks weigh 30 aum, while all other spellbooks weigh (level * 5) + 30.
The spell of protection only works if you are not wearing body armor.
Four new spellbooks are added (all level 7):
spellbook of charging (enchantment)
spellbook of phase (escape)
spellbook of astral eyesight (divination)
spellbook of summon nasty (clerical)
Encyclopedia entry

The Book of Three lay closed on the table.  Taran had never been allowed to read the volume for himself; now he was sure it held more than Dallben chose to tell him.  In the sun- filled room, with Dallben still meditating and showing no sign of stopping, Taran rose and moved through the shimmering beams.  From the forest came the monotonous tick of a beetle.
His hands reached for the cover.  Taran gasped in pain and snatched them away.  They smarted as if each of his fingers had been stung by hornets.  He jumped back, stumbled against the bench, and dropped to the floor, where he put his fingers woefully into his mouth.
Dallben's eyes blinked open.  He peered at Taran and yawned slowly.  "You had better see Coll about a lotion for those hands," he advised.  "Otherwise, I shouldn't be surprised if they blistered."

[ The Book of Three, by Lloyd Alexander ] 

See also
Spellcasting
The Book of the Dead
Novel
References

↑ src/spell.c in NetHack 3.6.6, line 179

↑ spell.c in NetHack 3.4.3, line 15

↑ spell.c in NetHack 3.4.3, line 350

↑ src/spell.c in NetHack 3.6.6, line 389

↑ initialspell in spell.c

↑ spell.c in NetHack 3.4.3, line 440

↑ cursed_book in spell.c

↑ Spells (learning, practising, and casting) in NetHack 3.4 by Kevin Hugo and Dylan O'Donnell

↑ src/spell.c in NetHack 3.6.0, line 395

↑ UnNetHack commit 65957ad: Applying a spellbook allows the player to flip through the pages, pro…

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