A replicant is a fictional bioengineered humanoid featured in the 1982 film Blade Runner and the 2017 sequel Blade Runner 2049 which is physically indistinguishable from an adult human and often possesses superhuman strength and intelligence. A replicant can be detected by means of the fictional Voight-Kampff test in which emotional responses are provoked; a replicant's nonverbal responses differ from those of a human. Failing the test leads to execution, which is euphemistically referred to as "retiring." Several models of replicant were produced. The first seen model, the Nexus-6, has a four-year lifespan to prevent them from developing empathic abilities (and, therefore, immunity to the test). The successor model, the Nexus-7, were limited experimental models with the ability to procreate. Nexus-8 and Nexus-9 replicants also have open-ended lifespans, but the Nexus-9 line was incapable of disobeying human orders. Term Origin In his novel Do Androids Dream of Electric Sheep? (the inspiration for Blade Runner), Philip K. Dick used the term android (or "andy"), but director Ridley Scott wanted a new term to avoid audience preconceptions. As David Peoples was re-writing the screenplay, he consulted his daughter, who was involved in microbiology and biochemistry, who suggested the term "replicating," the biological process of a cell making a copy of itself. From that, either Peoples or Scott came up with replicant, and it was inserted into Hampton Fancher's screenplay. Fictional History Blade Runner Prior to the events of the film, replicants became illegal on Earth after a bloody off-world mutiny. Six replicants escaped the off-world colonies, killing 23 people and taking a shuttle to Earth; the film focuses on the pursuit of the replicants by Rick Deckard, a type of fictional police officer/bounty-hunter called a "Blade Runner," who investigates, tests, and executes replicants. Escaped replicants (all Nexus-6 models): Roy Batty (played by Rutger Hauer), a self-sufficient combat model for the colonization defence program Pris Stratton (played by Daryl Hannah), a "basic pleasure model" for military personnel Zhora Salome (played by Joanna Cassidy), "trained for an off-world kick murder squad" Leon Kowalski (played by Brion James), a combat model or loader of nuclear fission materials An unnamed replicant—"Hodge" in early versions of the screenplay—killed in an electrical field at the Tyrell Corporation The sixth replicant was named "Mary" in early versions of the screenplay. The only mention of this replicant occurs in the 2007 "Final Cut" version — Captain Bryant's dialogue has been