Early in the 21st Century, THE TYRELL
CORPORATION advanced Robot evolution
into the NEXUS phase -- a being virtually
identical to a human -- known as a replicant.
The NEXUS 6 Replicants were superior
in strength and agility, and at least equal
in intelligence, to the genetic engineers
who created them.
Replicants were used Off-world as
slave labor, in the hazardous exploration and
colonization of other planets.
After a bloody mutiny by a NEXUS 6
combat team in an Off-world colony,
Replicants were declared illegal
on earth -- under penalty of death.
Special police squads -- BLADE RUNNER
UNITS -- had orders to shoot to kill, upon
detection, any trespassing Replicants.
This was not called execution.
It was called retirement.