"Blade Runner" is based on the Philip K. Dick novel Do Androids Dream of Electric Sheep? One of the most visually influential science fiction films ever made, it's easy to understand it's impact on the films that follow it, particularly in the genre of science fiction. See any classic works of Japanese anime( Akira, Ghost in the Shell, etc.) and you'll see "Blade Runner's" influence in nearly every frame. "Blade Runner" is as much a hard boiled film noir detective story as it is science fiction.

Los Angeles, 2019. Deckard (Harrison Ford) plays a hard-cop who has disturbing criminals to retire. They are called Replicants, used for slave labor to build off world colonies where healthy humans are migrating to now the planet is polluted. Their presence on Earth is illegal, and it's up to Deckard to find them and shoot them. All good science fiction should ask the question "What does it mean to be human?" What makes "Blade Runner" work so well is that it dwells on this question.