Sometimes this term is used in the same way as Stichomancy and Libromancy, which is a form of divination that seeks to know the future by randomly selecting a passage from a book, frequently a sacred text.
Among Christians, the Bible is most commonly used (in the Sortes Sanctorum), and in Islamic cultures the Qur'an. In the Middle Ages the use of Virgil's Aeneid was common in Europe and known as the sortes Virgilianae. In the classical world the sortes Virgilianae and sortes Homerica (using the Iliad and Odyssey) were used.
Because book owners frequently have favorite passages that the books open themselves to, some practitioners use dice or another randomiser to choose the page to be opened. This practice was formalized by the use of coins or yarrow stalks in consulting the I Ching. Tarot divination can also be considered a form of bibliomancy, with the main difference that the cards (pages) are unbound.
Another variant requires the selection of a random book from a library before selecting the random passage from that book. This also holds if a book has fallen down from a shelf on its own.
Bibliomancy is a type of Stichomancy: "divination from lines". Some sources refer to bibliomancy as a specialized form of stichomancy, often falsely attributing the word root "biblio" to "the Bible", rather than books in general.
In The Book of Webster's (1993) by J. N. Williamson, the sociopathic protagonist Dell uses the dictionary to guide his actions.
The popular 'lonelygirl15' internet fiction series mentions the use of bibliomancy as part of the main character's religious beliefs.
In the novel Man in the High Castle by Philip K. Dick, every major character uses bibliomancy, mainly by casting yarrow stalks in conjunction with the I Ching. Dick himself reportedly used this process for deciding key points in the story, even going so far as to blaming the I Ching for plot developments that he himself did not particularly care for.