The 1982 science fiction film Blade Runner, starring Harrison Ford and directed by Ridley Scott, loosely based on the novel Do Androids Dream of Electric Sheep? by Philip K. Dick, depicted a dreary, rainy, and polluted Los Angeles in 2019. In the film genetically manufactured, bioengineered biorobots called replicants—visually indistinguishable from adult humans—are used for dangerous and degrading work in Earth's "off-world colonies." After a minor replicant uprising, replicants are banned on Earth; and specialist police units called "blade runners" are trained to hunt down and "retire" (kill) escaped replicants on Earth.
The film, which became a cult classic for many reasons, including its unique sets, lighting, costumes and visual effects, is considered the last great science fiction film in which the special effects were produced entirely through analog, rather than digital or computer graphics methods, using elaborate model-making, multiple exposures, etc.
Scott's original director's cut of the film was first issued as a DVD in 1999. In 2007 the so-called "Final Cut" with a great deal of supplementary material, including three previous versions of the film, and a "definitive" documentary, even longer than the original film, was issued on DVD and Blu-ray. The documentary, and the collection of versions of the film, presented a superb opportunity to gain insight into way that Ridley Scott created a film.