Spell Memorizing and Spell Books: if a caster has studied his books within the last 24 hours or has not cast spells in any intervening day since he studied his books, he can spend his spell slots to cast any spell he knows. If he has not consulted his books, he can only cast spells he has studied from a scroll he has with him.
Magic-users begin with a level 1 spell book. Dues-paying members of magic guilds receive a spell book from the guild when they reach each new spell level. If they aren’t in a guild, they must create or acquire a new spell book for 750gp times the spell level. Likewise, if a magic-user loses his spell book he must create or buy a new one for the same price. If a magic-user captures an enemy spell book, he may use it to study spells he knows, once he has cast Read Magic on that particular spell in the book. All magic-users begin play with 1 scroll of 1 spell from their first level spell book in order to allow them to travel and function as magic-users.
Clerics receive a level 1 spell book from their temple when they reach 2nd level and each additional time they gain a new spell level. If a clerical book is lost or destroyed, the cleric is issued a replacement, but is also assigned a penance task for failing his god. Spell books from another religion do clerics no good.
Spell books are large and fragile. Each volume fills an entire back pack or saddlebag. A person cannot carry more than 1 volume (without some sort of magical help) in any circumstance. Each day a spell-book is carried on adventure, roll 2d6, if the total is 12, the volume has been destroyed in some mishap. If the book is subject to any sort of water, magical or fire attack on an adventure, it is automatically destroyed. A book can be transported safely if packed securely in a locked chest, lain flat in a sturdy 4-wheeled wagon that travels on a road. If travelling well-packed in a ship, there is a 1 in 20 chance every 3 days that it will be ruined on the trip.