1.The Combine is a fictional powerful alien race and empire from the first-person
shooter computer
game Half-Life 2. During the
game, it is also referred to as the Universal Union, and as "our benefactors" in
propaganda.
2.The Combine is a vast empire spanning multiple parallel universes. The empire is inhabited by an unknown number of sapient species, and appears to be governed by a race of bizarre, artificially evolved Advisors. The Combine expands its empire by invading worlds and enslaving the dominant species to be exploited as it sees fit. By manipulating these inhabitants through methods including bioengineering and implantation, the Combine creates a race of super-soldiers uniquely adapted for the environment of that particular
world. This process results in a highly mobile and adaptive military
force which is able to respond to any threat and crush any opposition. The reasons behind the Combine's imperialism remain unknown throughout the
game.
3.The Combine Advisors are the face of the Combine Empire, suggesting that they are probably the original master race behind the alien empire.
4.The primary military
force of the Combine on
Earth is the humanoid Combine Overwatch (referred to by
Doctor Breen as the "Transhuman arm of the Combine Overwatch"): humans who have been modified into "transhuman" (or "post-human", as referred to by
Dr. Kleiner) cyborgs. They are the most frequently encountered foes throughout Half-Life 2. This could also be another possible reason why they are called the Combine, because they are a "combination" of humans and alien technology.