Mr. Pohl had been a presence in science fiction since the 1930s, when he began to organize fan clubs and conventions. He published his first work — a poem under an assumed name — in 1937 and worked as an agent and editor before he turned 20.
He was a lifelong friend of the prolific author Isaac Asimov and, as an agent, helped publish Asimov’s first novel, “Pebble in the Sky,” in 1950.
But Mr. Pohl’s greatest achievement came through his own writing, which included more than 65 novels and 30 collections of short stories, many written with co-authors. He won science fiction’s Hugo and Nebula awards multiple times and in 1980 received an American Book Award (later called the National Book Award) for his novel “Jem: The Making of a Utopia,” about the efforts of three groups of people to survive after colonizing another planet.
Mr. Pohl touched on many common sci-fi themes in his writing: interplanetary travel, overpopulation, cryogenic preservation, cities under domes, parallel universes and colonies on Mars. But he may be most important as a pioneer of what has been called the “anti-utopian” branch of science fiction — or “sf,” as its aficionados often call it — in which an outwardly well-organized society disintegrates from internal pressures, rivalries and greed.
His first major novel, “The Space Merchants” (1953), written with Cyril Kornbluth, was built around the idea that the values of business and advertising had replaced governments, creating disastrous effects.
“They invented and played with ‘Sociological SF’ — alternate futures here on Earth, exaggerating and satirizing real-life social forces and trends,” author and critic Charles Platt wrote in “Dream Makers: The Uncommon People Who Write Science Fiction.”
“The Space Merchants” has never been out of print and is often cited as an influence on Philip K. Dick and other authors.
“Pohl’s work offers science fiction at its best,” Washington Post arts critic Joseph McLellan wrote in 1980. “Riddles posed, examined and solved; basic human problems ... woven deftly into an intricate plot; pure adventure happening to believable (if not deeply drawn) characters in surroundings almost beyond the borders of imagination.”
One of Mr. Pohl’s finest novels, by common consent, was “Gateway” (1977), which won the Nebula and Hugo awards. It was the first of five books about a lost civilization of aliens called the Heechee, who had left hundreds of spaceships at a docking station on an asteroid.
Future generations of space travelers attempted to master the controls of the abandoned spacecraft, which could carry them to other stars and unknown wonders. More often, though, the adventurers succumbed to age-old human emotions and frailties, and were plunged into oblivion.
“They were two lovely choices,” Mr. Pohl wrote in “Gateway.” “One of them meant giving up every chance of a decent life forever . . . and the other one scared me out of my mind.”
Frederik George Pohl Jr. was born Nov. 26, 1919, in New York City. He never completed high school, but in his 1979 memoir, “The Way the Future Was,” he wrote that he was captivated with science fiction by the time he was 10.
In the 1930s, he helped organize the Futurians, a group of sci-fi fans that included several future authors and editors.
After serving in Italy with the Army during World War II, he worked in advertising and as a literary agent. While writing his own novels and stories, he spent years as an editor at various publishing houses and was credited with publishing many notable writers, including Samuel R. Delany and Joanna Russ.
Mr. Pohl was always conscientious about the science in his fiction and sometimes revised his writing to accord with new research. Despite being a high school dropout, he was named a fellow of the American Association for the Advancement of Science and often spoke to military groups and NASA scientists.
In 2001, he published “Chasing Science,” a nonfiction book about his observations on astronomy, space travel, volcanoes, glaciers, archaeology, plate tectonics and other scientific matters. He also wrote the entry on the Roman emperor Tiberius for Encyclopaedia Britannica.
After living for many years in New York and New Jersey, Mr. Pohl moved to the Chicago suburbs in 1984, when he married his fifth wife, author and professor Elizabeth Anne Hull. She survives, along with four children from earlier marriages.
Mr. Pohl was named a grand master by the Science Fiction and Fantasy Writers of America in 1993 and was inducted into the Science Fiction Hall of Fame in 1998. His final novel, “All the Lives He Led,” was published in 2011.
In 1987, he wrote a novel about the Chernobyl nuclear disaster in the Soviet Union, which he had often visited for research.
“If you read science fiction,” he told The Post at the time, “nothing ever takes you by surprise.”