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Body count: seven (an unnamed replicant mentioned in a conversation between Bryant and Rick Deckard, Zhora, Leon Kowalski, Dr. Elden Tyrell, J.F. Sebastian, Pris, and Roy Batty). Eight counting Hannibal Chew, although his death is unconfirmed. In the Final Cut, two replicants are mentioned to have died in the conversation, making a body count of eight instead of seven (nine if Chew is included). Dave Holden, who got shot by Leon at the beginning, appears to have been killed, but it is hinted in the film that he survived the attack (which was later confirmed in Blade Runner: Revelations (2018)).
Director Sir Ridley Scott and director of photography Jordan Cronenweth achieved the famous "shining eyes" effect by using a technique invented by Fritz Lang and his cinematographer Eugen Schüfftan known as the "Schüfftan Process": light is bounced into the actors' and actresses' eyes off a piece of half-mirrored glass mounted at a forty-five-degree angle to the camera.
Joanna Cassidy (Zhora) was at ease with the snake around her neck because it was her pet, a Burmese python named "Darling".
(at around 38 mins) After Pris (Daryl Hannah) first meets J.F. Sebastian (William Sanderson), she runs away from him, skidding into his car and smashing the window with her elbow. This was a genuine mistake caused by Hannah slipping on the wet ground. The glass wasn't breakaway glass, it was real glass, and Hannah chipped her elbow in eight places. She still has the scar from the accident, as can be seen in Dangerous Days: Making Blade Runner (2007), the "making of" documentary of this movie.
Rutger Hauer came up with many inventive ideas for his characterization, like the moment where he grabs and fondles a dove. He also improvised the now-iconic line "All those moments will be lost in time... like tears in rain". He later chose "All those moments" as the title of his autobiography.
Ridley Scott: [opening scroll] The movie opens with a scroll about the replicants and the Blade Runners.