Traveller Book 3. Worlds and Adventures. The core rules for creating worlds using Traveller's unique Universal World Profile, plus animal encounters, and adventure creation. For Classic Traveller, the term Books has a special meaning: Books present additional rules on specific subjects, expanding on Traveller's basic concepts. Books run 48 to 56 pages and may be used independently or together, but all require the basic rules sets. The first three Books 1-2-3 were part of Basic Traveller; the other books were expansions on specific subjects: the Navy, the Military, the Scouts, the Merchants, and Robots.