This nonfiction essay, first published in Vertex in April 1973, discusses the grandfather paradox.

Welcome to Ringworld, an intermediate step between Dyson Spheres and planets. The gravitational force created by a rotation on its axis of 770 miles per second means no need for a roof. Walls 1,000 miles high at each rim will let in the sun and prevent much air from escaping. Larry Niven's novel, Ringworld, is the winner of the 1970 Hugo Award for Best Novel, the 1970 Nebula Award for Best Novel, and the 1972 Ditmars, an Australian award for Best International Science Fiction.

This early Niven story was the first of many to delve deeply into the legal and ethical implications of organ-transplant technology. It introduces Known Space's organ banks and the breed of criminals known as "organleggers".

This nonfiction essay, first published in Galaxy in March 1969, discusses the many uses, implications, and limits of teleportation, from personal transportation to interstellar travel.

Nothing quite prepared telepath Larry Greenberg for mind-to-mind contact with an alien. In the interest of science, Larry tapped the mind of Kzanol - and that was his first mistake. Kzanol was a thrint from a distant galaxy. He had been trapped on Earth in a time-stasis field for two billion years. Now he was on the loose, and Larry knew everything he was thinking. Thrints lived to plunder and enslave lesser planets - and what the planet Kzanol had in mind was Earth!

Fleet of Worlds takes a closer look at Human-Puppeteer (Citizen) relations and the events leading up to Niven's first Ringworld novel. Kirsten Quinn-Kovacks is among the best and brightest of her people. She gratefully serves the gentle race that rescued her ancestors from a dying starship, gave them a world, and nurtures them still. If only the Citizens knew where Kirsten's people came from.

His name was Biron Farrill and he was a student at the University of Earth. A native of one of the helpless Nebular Kingdoms, he saw his home world conquered and controlled by the planet Tyrann - a ruthless, barbaric Empire that was building a dynasty of cruelty and domination among the stars. Farrill’s own father had been executed for trying to resist the Tyrann dictatorship and now someone was trying to kill Biron. But why? His only hope for survival lay in fleeing Earth and joining the rebellion that was rumored to be forming somewhere in the Kingdoms.

The Mote In God's Eye is their acknowledged masterpiece, an epic novel of mankind's first encounter with alien life that transcends the genre. No lesser an authority than Robert A. Heinlein called it "possibly the finest science fiction novel I have ever read".

Once upon a time, in the magical land of San Francisco, there lived a not-so-ordinary girl named Laurel Pettigrew. She was supposed to be the Chosen One. The plan was simple: She would vanquish the great evil Tybus in an epic battle. But destiny had other ideas, and Laurel's performance in the whole heroics department was a colossal flop. Now, instead of being a legendary hero, Laurel's the resident pariah of the magic realm. And what’s worse, the dark wizard Tybus swooped in, took over the realm, and forced all supernatural creatures to live under his tyrannical rule.

the near future, Los Angeles is an all but uninhabitable war zone, wracked by crime, violence, pollution and poverty. But above the blighted city, a Utopia has arisen: Todos Santos, a thousand-foot high single-structured city, designed to used state-of-the-art technology to create a completely human-friendly environment, offering its dwellers everything they could want in exchange for their oath of allegiance and their constant surveillance.