Masterbook is a generic role-playing game that was created by West End Games as a follow-up to the multi-genre role-playing game Torg and the science fiction game Shatterzone, which used a modified version of the Torg system. As of January 2011, it is published by Precis Intermedia Gaming.
Like Torg, the Masterbook system utilized two complementary forms of in-game conflict resolution: a unified dice mechanic, which was based on a roll of two ten-sided dice, and a game-specific deck of cards (the MasterDeck, similar to the Drama Deck in Torg) that influenced random number generation, character actions, and the game's plot. Masterbook was used for several licensed properties, most notably The World of Indiana Jones, Tales from the Crypt, Species, and Brian Lumley's Necroscope. It was also used for unique settings such as Bloodshadows.
The system was, ultimately, a commercial failure despite these licenses, thanks to a combination of factors, including the high level of detail in game mechanics, the unusual synthesis of dice- and card-based conflict resolution, and the low level of player character power and effect even in fantastic or pulp-style settings such as Indiana Jones. This last factor was in direct contrast to Torg, which helped to isolate many fans of the game's predecessor and drive them to play games whose systems were more directly accommodating to their preferred style of gameplay.