In Blade Runner, the Nexus series of replicants – genetically engineered by the Tyrell Corporation – are virtually identical to an adult human being, but have superior strength, agility, a wider temperature range tolerance, and variable intelligence depending on the model. Earth law forbids replicants on the planet, except in the huge industrial complex where they are created. The law does not consider replicants human and therefore accords them no rights nor protection. Like all replicants, they had a limited lifespan, the Nexus-6 being genetically designed to have a very short lifespan of just a few years. Roy Batty, perhaps the most perfect of this series, and the other replicants returned to Earth to seek more life, but Tyrell said he was unable to alter the genetic make-up of the series.
Blade Runner (1982)
On Earth, androids known as replicants are illegal; especially feared is the new Nexus-6 variety, which cannot be reliably detected through the complicated eye scans used on previous models.
In fact, the Tyrell Corporation advertises this model as “More human than human.”
Roy Batty, model number N6MAA10816, is the leader of the renegade Nexus-6 replicants and the main antagonist of the film. He is very intelligent, fast, and skilled at combat, and yet still learning how to deal with developing emotions. He leads a few of his fellow replicants on what is inevitably a fruitless search for more life.
Replicant Leon Kowalski is a friend of Roy Batty. His emotions are at a much lower level of development than Roy’s, but he evidently believes in Roy’s quest for more life. Leon is classified mental level C. There is a debate about whether this means he is less intelligent compared to the average human, or just less intelligent compared to the average Nexus-6 Replicant.
Zhora is a Nexus-6 replicant who has returned to Earth with Roy Batty in search of a way to extend her lifespan. She has found work as an exotic dancer at Taffey’s Bar. In his scanning of photos obtained from a search of Leon Kowalski’s apartment, Deckard finds Zhora & identifies a custom tattoo of a snake on her neck, tying it to a snake scale he found in Leon’s bathtub.
Pris Stratton is the “basic pleasure model”, created for entertainment and thus even more of a slave-object than the others. However, she shows that she can be quite adept at manipulation of the human male as she uses her wiles to “make friends” with J.F. Sebastian, a man who until then, literally made his friends. Pris is also the girlfriend of fellow replicant, Roy Batty.
Rachael is a prototype Nexus-6 with implanted memories from Eldon Tyrell’s niece. Tyrell developed Rachael as an experimental replicant with false memory implants, so she would think she was human. Tyrell said that these memories would act as a “pillow” to cushion her developing emotions. As a result, Rachael behaved in a far more “human” manner than earlier model replicants.