"Known Space" (also the commonly used title for Larry Niven's future history science fiction series) is about 80 light years in diameter with 10,000 stars, including Human Space (40 light years diameter, 524 stars in 357 systems, 30 billion humans, ⅔ on Earth), as well as neighbouring Alien civilisations.

Important Alien civilisations include the Puppeteers, paranoid pacifist herbivore centaurs, and the Kzinti, carnivorous warlike felines, who fought multiple wars over hundreds of years against the Humans, being defeated each time.

The game is intended to be set on the Ringworld itself, an enormous single world discovered at the far reaches of Known Space, a ring around a sun at approximately the orbit of the Earth.

They can be anthropologists, artists, doctors, police, or even zealots, who will explore the mysteries of this huge artificial world and its inhabitants.

[citation needed] A character is initially defined by his species or world of origin, which affects characteristics (for example, by determining the gravity to which it is accustomed).

At creation, each character gets to spend a number of points (based mainly on age, Education, and Intelligence) on skills determined by interests or career choice.

The authors are credited as Greg Stafford, John Hewitt, Sherman Kahn, Lynn Willis, Sandy Petersen, Rudy Kraft, Charlie Krank, Ed Gore, and Jeff Okamoto.

There are suggestions for creating scenarios and campaigns, and information on technology of various humanoid species of the Ringworld, and additional rules, including gravity, Credit Rating, and psionics.

The characters are hired by Captain Gregor Lopez, famous explorer, for a journey to the Ringworld that does not go completely as planned.

The authors are credited as Greg Stafford, John Hewitt, Sherman Kahn, Lynn Willis, Sandy Petersen, Rudy Kraft, and Charlie Krank.

The book starts with a diagram of the Ringworld and its star, EC-1752, new humanoids, aliens, plants and animals, technological objects, and original errata.

Phil Masters reviewed Ringworld for White Dwarf #59, giving it an overall rating of 6 out of 10, and stated that "This game takes a superb background idea, applies a good system of mechanics to it, and comes back with a disappointing result.

The actual mechanics of the game are top quality, yet background and atmosphere are what make or break a campaign, and in Ringworld this aspect could be somewhat daunting to the uninitiated.

Swan also pointed out that although there was a lot of background material, "there's not much help of any kind for the Ringworld referee; not only does he have his hands full managing a planet roughly the size of 3 million Earths, the game presumes he has a basic understanding of physics, embryology, and other sciences.

[7] James Davis Nicoll in 2020 for Black Gate said "Production values were very high, as was the price [...] Yes, that's a Ralph McQuarrie cover.

LNRW: RABtGA was also doomed, because scarcely had the game come out before Niven made a lucrative media deal and yanked the rights back from Chaosium.