Blade Runner is set in Los Angeles on November 2019. At this time, the former police officer Rick Deckhard is brought by Officer Gaff to his former supervisor, Bryant. As a “Blade Runner,” Deckhard is informed that four replicants (bioengineered creatures) have come to Earth illegally and they must be “retired” immediately. The replicants, which are Tyrell Corporation Nexus-6 models, are known to only have a four-year lifespan so their reason for coming to Earth must be to put an extension to their short lives.
Deckhard is shown a video demonstrating how replicants can be singled out based on their reactions to certain questions. On the video, a man named Holden asks the test subject, Leon about his mother. Not answering the question, Leon shoots Holden on the spot. Deckhard’s mission now is to track down Leon as well as the other replicants named Roy Batty, Zhora and Pris and kill them all. Deckhard does not want the job but Bryant makes some threats that push Deckhard to accept.
Deckhard starts tracking down the replicants by going to the Tyrell Corporation first. He wants to confirm if the test shown on the video works for all Nexus models. In Tyrell Corporation, Deckhard meets Rachael, an experimental replicant who thinks that she is a human. She is given false memories by her maker, Dr. Eldon Tyrell. These false memories allow her exhibit certain emotional tendencies. Because of this, further test is required to confirm if she behaves as a human or a replicant.
Things becomes complicated when Deckhard’s investigation when he learns that the illegal replicants are looking for Tyrell because they want him to extend their lives. Roy and Leon go to a laboratory that specializes in making replicant eyes. There, they find J.F. Sebastian, a genetic designer who is a close associate of Tyrell. Meanwhile, Rachael goes to Deckhard’s house and tries to convince him of her humanity. She hands him a family photo with her in it but Deckhard reveals that the photo is only part of the false memories that Tyrell has implanted on her. Rachael leaves in haste after this revelation. On the other hand, Pris searches for Sebastian and tries to win his trust.
Deckhard locates Leon’s room and there he finds a photo of Zhora. Clues on the photo lead him to a strip club where Zhora works. He tracks her down and kills her. After finishing the assignment, Bryant orders Deckhard to also kill Racheal who has gone missing from Tyrell Corporation. When Deckhard finds her, Leon tries to kill him but Rachael saves him by shooting Leon with Deckhard’s pistol. The two retreat to Deckhard’s place and Deckhard vows not to search for Rachael anymore.
Meanwhile, Roy informs Pris that the rest of their colleagues are dead. When he sees their dilemma, Sebastian tells them that he has Methuselah Syndrome, a genetic premature aging disorder that is currently shortening his lifespan. Sebastian and Roy decide to break into Tyrell’s house and Roy forces him to extend their lives. Tyrell tries to convince Roy that he can’t do that. Roy rants about the things that he has done but Tyrell just commends him for doing so much in such a short time. Roy ends up killing Tyrell. After witnessing this, Sebastian tries to escape but Roy catches up to him.
When he reaches Sebastian’s apartment, Deckhard is attacked by Pris but he kills her instead. At that moment, Roy comes back from Tyrell’s house. He sees Deckhard and runs after him. Simultaneously, his body starts shutting down. The chase ends up in the roof top where Deckhard tries to jump on another building. He misses and just manages to barely hang onto building. On the other hand, Roy jumps from one building to another without so much breaking a sweat. When Deckhard loses his grip, Roy saves him and pulls him up on the roof. Roy then dies and Gaff arrives shouting some warnings about Rachael. Deckhard rushes to his apartment and he finds Rachael sleeping on his bed. Deckhard spots an origami on the floor which reminds him that Rachael’s life is still in danger. The movie ends with Deckhard and Rachael rushing out of the apartment.