Blade Runner is a 1982 American science fiction film, directed by Ridley Scott and starring Harrison Ford, Rutger Hauer, and Sean Young. The screenplay, written by Hampton Fancher and David Peoples, is based loosely on the novel Do Androids Dream of Electric Sheep? by Philip K. Dick. The film depicts a dystopian Los Angeles in November 2019 in which genetically engineered organic robots called replicants—visually indistinguishable from adult humans—are manufactured by the all-powerful Tyrell Corporation as well as other mega manufacturers around the world. Their use on Earth is banned, and replicants are exclusively used for dangerous, menial or leisure work on Earth's off-world colonies. Replicants who defy the ban and return to Earth are hunted down and "retired" by police special operatives known as "blade runners". The plot focuses on a brutal and cunning group of recently escaped replicants hiding in Los Angeles and the burnt out expert blade runner, Rick Deckard, who reluctantly agrees to take on one more assignment to hunt them down. Blade Runner initially polarized critics: some were displeased with the pacing, while others enjoyed its thematic complexity. Despite the box office failure of the film, it has since become a cult classic, and is now widely regarded as one of the best films ever made. Blade Runner has been hailed for its production design, depicting a "retrofitted" future, and it remains a leading example of the neo-noir genre. Ridley Scott regards Blade Runner as "probably" his most complete and personal film. In 1993, Blade Runner was selected for preservation in the United States National Film Registry by the Library of Congress as being "culturally, historically, or aesthetically significant".