From the back of the book: Shinobi Ryu includes a detailed history and description of a number of historical shinobi (aka "ninja") ryu or clans, NPC write-ups, and a sample shinobi village. Shinobi Ryu contains additional information for both GMs and players, including: - New Ryu (clans)! - New NPCs! - New Shinobi Profession Templates! - A Shinobi village, with map & key! ... and more! Can be used with Sengoku, the Usagi Yojimbo Roleplaying Game or any feudal Japan roleplaying game.