Spell memorisation is the process by which you learn spells from spell books in your inventory. This can be done by clicking on the spell book, viewing the Memorisation tab of your inventory screen, or pressing M and selecting the desired spell from the list.
While any character may gain access to spells, the following restrictions apply:
- You must be carrying or standing over a spellbook with that spell in to memorise that spell.
- You can memorise at most 21 spells. A scroll of amnesia or Sif Muna's Forget Spell ability will allow you to forget unwanted spells to free up space.
- Each spell has a spell level, ranging from 1 to 9. You can only memorise a total of (Experience Level-1 + (2*Spellcasting)) levels of spells.
- You can't memorise while confused or berserk.
- You can't memorise a spell whose level is higher than your experience level.
- In addition, some species cannot learn certain spells:
- Deep Dwarf: Regeneration.
- Felid: Excruciating Wounds, Portal Projectile and Spectral Weapon.
- Gargoyle: Statue Form and Sublimation of Blood.
- Ghoul: Beastly Appendage, Blade Hands, Spider, Ice, Hydra, Statue and Dragon Forms; Necromutation, Death's Door, Borgnjor's Revivification and Sublimation of Blood.
- Mummy: Same as ghouls, plus Regeneration.
- Vampire: Necromutation, Death's Door and Borgnjor's Revivification.
All spells not affected by the conditions above can be memorised, however memorisation takes the spell level of the spell you are trying to learn + 1 turns to complete (during which you cannot do anything else), and should you take damage during this time your memorisation will be interrupted.
In 0.22, spellbooks will be merged into a spell library (the memorisation menu) when picked up, meaning you will be able to memorise any spell that you have seen without having to carry around a spellbook containing that spell. This memorisation menu will allow hiding spells which you have no interest in learning (these can then be unhidden later), and using ctrl-f to find spells in the spell library. This will also remove the feature of being able to memorise from books on the floor, because the book has to be picked up for the spells to be added to the spell library.
Prior to 0.12, your chance of success at memorising a spell was related to your chance to cast the same spell. Failing to memorise a spell had no effect, except from a Book of Annihilations, a Grand Grimoire or a Necronomicon. In these cases, you'd suffer a (likely high level) miscast effect from Conjurations, Summonings or Necromancy, respectively.