These books are a DICELESS fantasy combat system. Each player has a book, and you play by giving your book to your opponent, who reciprocates. You each pick a maneuver from your list of options, and tell the other player a page number. You each turn to the specified page number, and see what the other person is doing. For instance, you may choose to lunge at me, while I choose a side swing. When I turn to your page, I see you lunging at me, and when you turn to my page, you see yourself getting a hit on me. After I take a specified number of hits, I have lost the combat. It's very easy (the complete rules are included on each book) and very quick.