The Combine (/ˈkɒmˌbaɪn/ COM-byne) is a multidimensional empire which serves as the primary antagonistic force in the 2004 video game Half-Life 2, and the subsequent episodes developed by Valve. The Combine consist of organic, synthetic, and heavily mechanized elements. They are encountered throughout Half-Life 2 and its episodic expansions, as well as Half-Life: Alyx, as hostile non-player characters as the player progresses through the games in an effort to overthrow the Combine occupation of Earth.