These heavy leatherbound encyclopaedias of magic know more ancient and obscure lore than their thousands of pages actually hold. To use one, the reader must first ask a question aloud and open the book, which takes a full-round action. The book grants a +5 competence bonus to the reader’s Knowledge (arcana) check to answer this question, as on a successful check the book magically opens at the correct “page”.
If the check is successful, the page can be bookmarked for later perusal. If unsucessful, however, the book simply does not know the answer to this question and opens at a random page on some other topic. The book cannot answer a failed question even if asked by another person, or if the reader tries to ask a different question to learn the same piece of knowledge.
As the name suggests, each Tome is actually one in a series of four books. If the reader consults two differently-numbered books the bonus granted increases to +7. If three different books are consulted, the bonus increases to +8, and if all four are consulted it increases to +10. The process takes one round per book checked. As with a normal Knowledge skill check, however, retries are not possible - if the reader consults each Tome seperately it can only increase the bonus to the original roll as described above, not allow multiple attempts at the roll.
Variations on this book are known to exist which contain different sorts of knowledge, such as the Tomes of Planar Lore and Encyclopaedias of Engineering. These books should not be confused with the powerful ability score increasing items such as Tome of Clear Thought or Tome of Understanding.
Faint divination; CL 5th; Craft Wondrous Item, identify, creator must have at least 8 ranks in Knowledge (arcana); Price: 2,500gp; Weight: 10 lb.