Second Variety

"Second Variety" is a science fiction novelette by American writer Philip K. Dick, first published in Space Science Fiction magazine, in May 1953, with illustrations by Alex Ebel. Set in a world where a war between the Soviet Union and the United Nations has reduced most of the world to a barren wasteland, the story concerns the discovery, by the few remaining soldiers left, that self-replicating robots originally built to assassinate Soviet agents have gained sentience and are now plotting against both sides. It is one of many stories by Dick examining the implications of nuclear war, particularly after it has destroyed much or all of the planet.

The story was adapted into the film Screamers in 1995. The short story "Jon's World", written in 1954, serves as a sequel.