A bog-standard, normal, ordinary spellbook

Spell Books

The only difference between them is that clerics call theirs prayer-books, there is otherwise no functional difference.

A spell-using character can, with study, understand and use the contents of the book of another character of the same class, but no other magic-using class. That is, a magic-user could use spells from the book of another magic-user, but not from an illusionist's book.

General Description

Before the introduction of modern methods of paper production, most European books were made of wood, metal and leather. They were heavy, bulky and expensive. Spell books are no exception; in fact, if anything, they tend to be even more expensive than their mundane brethren.

The example shown here (a medieval Bohemian manuscript of 1397) is the sort of thing one might expect to find in your average wizard's workroom or backpack. It's a no-nonsense book designed for the road — the loose soft leather flap is called a chemise binding, and is supposed to be wrapped around the body of the book to protect the edges of the pages from dust, dirt and the elements. The whole package is held together with straps, which in this case latch on to simple prongs on the front cover, though more elaborate latches and buckles were also commonly used.

It consists of about a hundred leaves, of which the first twenty or so are paper (added at a later date than the main body of the book), and the remainder are vellum, which is a fine-grained unsplit lambskin, kidskin, or calfskin prepared especially for writing on or for binding books. The covers are of leather-bound wood, the vulnerable corners protected by brass plates. The dimensions of the book are roughly 20cm x 30cm (that's just a little narrower than an AD&D rulebook, and a little taller) and about 11cm thick. It weighs just on 6kg (about 13½ lbs).

This would be an example of a "lowest common denominator" spell book. They may be substantially more elaborate than this one, and they may be much larger and much more expensive. Very valuable books would be likely to include cunningly designed latches and locks to keep out prying eyes and fingers, and covers may be made of exotic hides or metals. And, of course when you're dealing with wizards, there's always the likelihood of magical traps to contend with.

So, What's Inside?

A single arcane (wizard or illusionist) spell book (like the one shown here) can contain up to 100 levels worth of spells; about 1 level per leaf (both sides of one page). They tend to be bulky and heavy, and a nuisance to keep dry and safe. They're also valuable, and a prime target for the nimble-fingered, so watch out.

The prayer-books of clerics differ from wizards' spell-books in that they do not contain individual spells to be learned, but rather the prayers, chants, and meditations required to be able to create their divine miracles. At minimum, a cleric will need one prayer book for each two levels of spells: that is, a "beginner" book for spells of levels one and two, an intermediate grade book for levels three and four, and so on. A High Priest, able to create seventh-level miracles, would need four Holy Books.

The Getting of Magical Spells

When a magic-user character is created, they begin at level one with a rather limited magical repertoire consisting of Read Magic and 1-4 other randomly determined first-level spells. These are the spells allowed them by their erstwhile master before being thrust out into the world to make their own way.

When they train to rise in level, they come away from their training with one new spell of their new level. Note that this assumes that the training is done under the guidance of a Master of higher level; if the wizard self-trains, then no new spell is gained.

Apart from the above circumstances, new spells must invariably be garnered in the course of the wizard's adventuring career.

The idea of a free exchange of knowledge is far from common amongst the wizarding community, and as a rule, magicians tend to become more and more secretive about their knowledge and skills as they gain in power. The only other wizard who can be relied on to share knowledge is the Master under whom one's apprenticeship was taken, and even then only if the Master and apprentice parted on good terms, and only to a very limited degree. The price for this cooperation is generally an undertaking to perform any tasks required by the Master, and naturally those tasks will likely be those the Master would rather not have to take care of themselves, due to their unpleasant or tedious or dangerous nature (or, likely enough, all three). Note that this is pretty much the only reason that any wizard would burden him or herself with an apprentice at all; few magicians are of a naturally charitable nature.

Transcribing Spells From Scrolls

The most common source of new spells is from scrolls: bought, found or stolen — and only the most common and puny of spells will generally be available for sale. Scrolls, unlike the spells inscribed within a spellbook, are essentially charged one-use magic items and must be reverse-engineered to be transferred into a reusable set of instructions. This will require the use of one Read Magic spell per two spell-levels (round up), to read the text without activating its magic, and to allow a literal transcription to a non-volatile form. Once that is done, the wizard can attempt to transcode the scroll text into their own notational system as if translating spells from another wizard's spellbook (see below).

Note that this transcription will not activate the spell, but it will ruin the spell on the scroll.

Transcribing Spells From The Spellbook Of Another

Every wizard, in the course of their career, develops their own unique and idiosyncratic system of notation, based originally on that taught to them by their original Master, but diverging further and further as they undergo their own unique experiences and develop their own mnemonic codes and so on. For this reason, the spellbook of another wizard will almost never be immediately comprehensible, and will inevitably require careful study to allow a workable translation.

Assuming that magical means of translation aren't available, the chance of being able to decipher enough of a specific wizard's code to be able to then start transliterating the spells within his or her book(s) has a base of 50%, assuming the writer of the book is of the same level as the magician attempting to decode it.

This is modified by plus or minus 5% per level of difference between the reader, and writer at the time of writing. For example, a 5th level reader trying to decode the book of a 10th level wizard (5 levels below) would have a 25% chance of success. The same 5th level reader deciphering the book of a 1st level magician (4 levels above) would have a 70% chance to succeed.

This initial period of study takes 4-24 days, after which the d100 is rolled for success. A further period of study can be employed following a failure, but if that too fails, the spellbooks will remain incomprehensible until the reader has risen at least one level, at which time they can try again.

If the reader succeeds, they can then begin translating the instructions within the book into their own system of notation. As a rule, this will take 2d4 hours of uninterrupted concentration per page, and will, of course, require access to inks, pens, and drawing instruments. This process requires absolute precision, and is not the sort of thing it would be wise to undertake in the Wild or the tunnels of the Underdark.

The chance of successfully transcribing a spell is the same as that of deciphering the notational system, but there is no limit to the number of times a failed attempt can be repeated. Note that in general the only way to find out if you have correctly transliterated the instructions is to attempt to cast the new spell.

Decoding a spell already known is considerably easier than attempting to decode instructions to one that is completely new. Add 5% to the chance of a successful transliteration for every character level above that of the level required to cast the known spell. For example, a 5th level decoder attempting to transliterate a known 3rd level spell would be at ±0 to their chance of success, while a 7th level caster would add +10% to the chance of success (2 levels difference = +10%).

Each time a spell from a particular source is successfully transliterated, add 5% to the overall chance of success, to a maximum of +25%, as the decoder becomes more and more familiar with the original system. For this reason, it can be worth while spending the time to decode the descriptions of low-level spells the transcriber already knows, to gain familiarity with the notation system before moving on to completely unfamiliar spells. Success is never absolutely guaranteed however, and can never rise above 99%. (This includes multiple spells taken from scrolls, assuming that all were created by the same wizard).

Learning Daily Spells

All magic-using characters have limitations on the number of spells they can have in mind at any one time. A caster need not fill up their minds with spells all at once — spell "slots" can be left free, to allow for some flexibility in which spells to learn — but under normal circumstances, the daily limit cannot be exceeded. Once a spell slot has been filled, even if it is emptied either by casting the spell, by consciously forgetting it, or by being knocked on the head, it cannot be refilled until the following day.

Generally speaking, a new magical day begins at dawn.

Learning a spell, or meditating on a miracle, takes 15 minutes per spell level of study and/or meditation and what-not. Every iteration of a spell must be learned individually — even if you have sufficient slots to cast three Lightning Bolts in a day, if you learn it only once, you can cast it only once.

Losing Spells

You will lose all of your learned spells in mind if you are knocked unconscious, if you are reduced to zero hit-points or below, if you are killed and then revived, or if you are the target of a Feeblemind spell.

Sleep, either natural or magical, will not remove any learned spells.

You can also choose to forget a spell, a process which takes one minute per spell level. You might do this in order to replace an un-cast spell with a different one of the same level at the beginning of the day, or in preparation for the next day's spell learning session.