Creatures in The Half-Life Series - Combine

The Combine, also referred to as the Universal Union, is a fictional multidimensional empire, which serves as the primary antagonistic force in the Half-Life video game series, developed by Valve Corporation. The Combine consist of alien, synthetic and human elements, and dominate Earth. They are regularly encountered throughout Half-Life 2 and its episodic expansions as hostile non-player characters as the player progresses through the games in an effort to overthrow the Combine occupation of Earth.

The Combine are frequently shown as harsh rulers over the citizens of Earth, suppressing dissent with brutality, policing using violence and using invasive surgery to transform humans into either soldiers or slaves. Throughout the games, the player primarily battles with transformed humans as well as synthetic and mechanical enemies that are the product of Combine technology. The atmosphere generated by the dystopian Combine state has been praised by reviewers, although the artificial intelligence of the transhuman Combine characters was thought to be inferior to that of other characters in Half-Life 2. In addition to their role within the Half-Life series, the Combine have been adapted for machinima productions and one synthetic enemy character of the Combine has been made into a plush toy by Valve.