D&D Library Rating System

This was originally posted in 1997, when I was playing AD&D regularly.

Miguel Bazdresch came up with the following system for rating books and, subsequently, libraries. This is the slightly revised version:

"Any given book has a rating from 0 to 20. A 0 book contains nothing especially relevant - maybe kitchen recipes, first-grade history, or simple drawings. As the rating gets progressively higher, the book gets more and more useful and rare. They start talking about a particular creature’s weaknesses or features, useful historical insights (read: treasure sites), up to how to create potions, magical items and magical creatures, how to conjure undead, maybe even how to turn into a lich.

"A book can also have a subject matter, for example, it might be a ‘rated 3 book on golems,’ for example. I might also rule that in order to build a golem, a wizard needs 100 book points on golems. For the wizard to turn into a lich, maybe 500 points would be required. That is, of course, in addition to any time, material or other requirements.

"Books on general stuff only have a rating, not a subject matter. These books might be useful as general background. For example, a wizard who is researching a 6th level spell might need 60 points of general knowledge in his library.

"So to describe a library, public or private, large or small, I usually use a rating. For example, your large library could be composed of 1000 0-books, 100 1-books, up to maybe 2 15-books. If the characters get to one of the useful books, be prepared to tell them something useful. But in general, these books would be guarded by clerics or something.

"This also makes wizards in my campaigns eager to search in defeated wizard’s or monster’s libraries, not only for spellbooks, but for special books also. The thrill of finding a 20-book on staves is comparable to that of finding a 6th level scroll. The anticipation on building a large library feels great, also. A wizard can feel proud not only for his filled-up spellbook, but for his triple-digit library also."

To this system, I added:

"If you have a book that is rated low (say, 0-5), you could probably read it and understand it immediately. If you have a moderate book (say, 6-12), you could study it for a while to understand it, or maybe it would require a particular proficiency. Beyond that (rated 13-20), you would have to have 1-3 prerequisites to be able to use the book:

1. You would have to have already studied 10-50 points of that subject to understand the book.

2. One of the books you studied within those 10-50 points should have been of a complexity level of at least 8-12.

3. You could understand it with the correct proficiency/proficiencies.

"That way, you don’t have Joe Mage picking up a series of books on advanced studies in the art of Neuromancy (each rated 20 points), and being thoroughly educated in that art. He would have no basis to understand the advanced topic!"

As always, feedback is welcome.