The Combine are a fictional multidimensional alien empire which serve as the primary antagonistic force in the 2004 video game Half-Life 2 and its subsequent episodes developed and published by Valve Corporation.

The Combine are depicted as cruel rulers, suppressing dissent with brutality, using excessive violence to police humanity, and forcibly performing surgery on some to transform them into slaves.

The name "Combine" itself is a tribute to Ken Kesey's novel One Flew Over the Cuckoo's Nest, which features a collection of authorities which mechanistically manipulate and process individuals.

[4] Combine soldiers in Half-Life: Alyx are voiced by actors including Rich Sommer, Isaac C. Singleton Jr., Jason Vande Brake, Michael Schwalbe, Rajia Baroudi, and Rick Zieff.

[5] Little is revealed of the Combine's activities outside of Earth, but dialogue in Half-Life 2 states that they control worlds of various dimensions inhabited by a range of species.

The military Overwatch forces of the Combine attack human resistance bases in an effort to further solidify their authority in the urban centers.

Human citizens are clad in blue uniforms, living in designated apartment blocks and move around to different cities or locales in passenger trains by the Combine's will.

[1] The heart of the Combine's command over Earth in Half-Life 2 is the Citadel, a large tower constructed by them which reaches both tens of thousands of feet into the sky[8] and deep underground.

In addition, a variety of combat machines appear, ranging from APCs and helicopter gunships to a giant 'smart wall' enclosing occupied cities and gradually destroying anything in its path, as well as a number of weaponized alien 'synths'.

[13][14] Although Advisors are usually seen in protective pods guarded by Combine soldiers, they also possess psychokinesis with which they are able to float through the air and immobilize other creatures so that their proboscis can examine victims without interference.

[15] The Civil Protection is the Combine's primary law enforcement agency on Earth, whose ranks are drawn from unmodified, volunteering humans.

[12] Civil Protection makes use of smaller drones called manhacks, which are equipped with razor-sharp rotating blades to attack targets with laceration injuries.

[13][18] Militarily, the Combine make use of both synthetics, creatures augmented with machinery, and traditional machines such as armored personnel carriers and attack helicopters.

[12] The most prominent of the synthetic machines are the insect-like gunships; and Striders, 50-foot-tall (15 m) armored creatures which walk on three legs and are armed with a high powered cannon and a head-mounted pulse turret.

Earth's surrender was negotiated by Dr. Wallace Breen, administrator of the Black Mesa Research Facility at the time of the incident, who discovered a means of communicating with the Combine.

After Alyx acquires an encrypted copy of the message to be sent, Overwatch forces desperately attempt to stop the pair from escaping the city, spurred on by Combine Advisors.

[24] They also discover that Alyx's encrypted data from the Citadel can reverse the portal, and so traverse the countryside to deliver the packet to another resistance headquarters at White Forest.

[note 1] The related Portal series hints at the presence of the Combine, with malevolent AI GLaDOS claiming that she is the only thing standing between Chell and "them".

1UP.com praised the "epic feel" built up by the Combine and their harsh rule of City 17 in Half-Life 2, stating that this created "a world governed by newspeak, decorated with urban decay, and lacking any hope".

While stating that overall the artificial intelligence for the game was "extremely competent", they expressed the opinion that Combine non-player characters "could have used better survival instincts", citing their reluctance to take cover and tendency to charge at the player and into a shotgun blast.

[36] In Playing Dystopia, the Combine are directly compared with the Party in George Orwell's Nineteen Eighty-Four as a totalitarian regime organized according to an ideology.

The book notes that Dr. Breen represents an archetypal father figure who lies that the Combine have created a utopia in order to justify the invasion.

The Combine also create the image of a utopia through mind manipulation and propaganda, causing humanity to accept a false sense of safety and "womb-like security".

The suppression field deployed by the Combine to prevent new births and destroy the concept of the family was also compared to P. D. James' The Children of Men.

[38] Aliens in Popular Culture describes the Combine's uniforms and architecture as referencing communism and fascism, comparing its overtones to Starship Troopers.

One issue shows a Civil Protection briefing for attempting to capture the comic's protagonist Gordon Frohman, in which officers are instructed to cluster around explosive barrels, seek cover on unstable structures and rappel down from bridges in front of fast moving vehicles.

[43][44] PC Gamer UK noted that "the suggestion, of course, is that Scientology's purpose or self-image in some way resembles that of the homogenizing intergalactic murderous alien collective".