One-on-One (alternate title: 1-on-1) Adventure Gamebooks is similar to the 'Lost Worlds' and 'Ace of Aces' games. Each player has a different adventure book offering a series of choices. At each point, the choice each player makes drives the story to a different outcome.There were 11 gamebook sets published the subject matter ranged from a generic fantasy duel ('Castle Arcania', whcih pitted a swordsman against a mage), to comic books ('The Doomsday Device', with the Fantastic Four facing Dr. Doom). - BoardGameGeek