Books are both randomly generated and prewritten bits of texts scattered throughout the world of Qud.
Aside from reading them for their contents, their secondary function is to donate these books to Sheba Hagadias, Librarian of the Stilt for experience.
How much each book is worth in experience is based on the commerce value of the item. The formula is as follows:
A book with the "illuminated" modifier has a commerce value that is 30% higher, which amounts to a 69% higher experience gain when given to Sheba Hagadias.
Yellow books are not markov chain generated and have their contents in Books.xml. This does not mean they do not have some form of randomness to them, however. Corpus Choliys will always have randomized cures. The two books that do not have a Books.xml entry are A crumpled sheet of paper and Heirlooms of Qud, which have their own cs file for generation.
Green books are recipe books which teach the player the recipes within once read.
White books are markov generated. Each one has a chance of containing one clue of the location of the Ruin of House Isner.
List of Books
White books, also referred to as markov books due to their content generation method, have a randomly assigned commerce value from 50-150. This means that they will grant 100 to 900 experience, and 169 to 1,521 experience when illuminated.
Note that merchant advertisements cannot be donated.
Sultan relics can sometimes appear as books with random markov-chain text, and a special relic effect.