Ringworld

The Pak looped a million-mile-wide, harder-than-steel ribbon around a star, and set the ribbon spinning. Like a lariat the scrith band spun evenly, in an orbit comparable to Earth's. Air came, and water and soil, and beneath a sun always at high noon lived and died man-like beings who knew no other reality. Mysteriously, the Pak died out, but upon the Ring there came to be many species with intelligence - Ghouls, City Builders, Grass Giants, Machine People - and their empires and destinies grew bright or dimmed... ~ COMPONENTS: EXPLORER BOOK; TECHNOLOGY BOOK; CREATURES BOOK; GAMEMASTER BOOK; OTHER COMPONENTS include explorer sheets, game reference sheets, visions of Ringworld (four essays), the Ringworld printout.