The Fringe War is a fictional ongoing conflict in Larry Niven

Larry Niven

Laurence van Cott Niven / ˈlæri ˈnɪvən/ is an American science fiction author. His best-known work is Ringworld , which received Hugo, Locus, Ditmar, and Nebula awards. His work is primarily hard science fiction, using big science concepts and theoretical physics...

's Ringworld

Ringworld

Ringworld is a Hugo, Nebula, and Locus award-winning 1970 science fiction novel by Larry Niven, set in his Known Space universe and considered a classic of science fiction literature. It is followed by three sequels, and preceded by four prequels, and ties into numerous other books set in Known Space...

series. It takes place in the novels The Ringworld Throne

The Ringworld Throne

The Ringworld Throne is a novel by Larry Niven, first published in 1996. It is the direct sequel to his previous work The Ringworld Engineers...

and Ringworld's Children

Ringworld's Children

Ringworld's Children is a 2004 science fiction novel by Larry Niven, the fourth in the Ringworld series set in the Known Space universe. It describes the continuing adventures of Louis Wu and companions on Ringworld.-Plot summary:...

.

Once the existence of the Ringworld is revealed to the Human and Kzinti governments, both factions attempt to invade the Ringworld in order to acquire its advanced technology, and possibly also to colonize its vast amounts of land. The Ringworld is defended by a loose alliance of native Protectors

Pak Protector

Pak Breeders and Pak Protectors are two forms of fictional life in Larry Niven's Known Space universe. The Pak first appeared in "The Adults," which appeared in Galaxy in 1967; this story was expanded into the novel Protector by Larry Niven...

, each from one of the major Hominid

Hominids of the Ringworld

The Hominids of the Ringworld, like the humans of Larry Niven's other works about the Known Space fictional universe, are descendants of the species called the Pak, whose "breeder" stage resembled Homo habilis, and who utilize a symbiotic virus to then develop into a hyper-intelligent Protector...

 species of the Ringworld. Their main defense is a massive laser

Laser

A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...

 powered by artificial solar flares, capable of vaporizing an asteroid

Asteroid

Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...

 at distances of light-hours.