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 replicants are referred to in the two Blade Runner films. The first seen, the Nexus-6, has a four-year lifespan. The successor model, the Nexus-7, is a limited experimental model with the ability to procreate. Nexus-8 and Nexus-9 replicants have open-ended lifespans. The Nexus-9 line was incapable