Half-Life: Opposing Force

1999 expansion pack for the science fiction first-person shooter video game Half-Life

Half-Life: Opposing Force is an expansion pack for the game Half-Life. The game was developed by Gearbox Software and Valve and published by Sierra Entertainment for Windows in 1999. Opposing Force was the first expansion for Half-Life and was announced in April 1999. Lead designer Randy Pitchford believed Gearbox was selected to develop Opposing Force because Valve, the creators of Half-Life, wanted to focus on their future games. The name is a pun on the scientific term “opposing force”.

Half-Life: Opposing Force
Developer(s)Gearbox Software Edit this on Wikidata
Publisher(s)Sierra Entertainment (CD-ROM) Valve Corporation (Steam)
Designer(s)Randy Pitchford Edit this on Wikidata
Composer(s)Ben Houge Edit this on Wikidata
SeriesHalf-Life Edit this on Wikidata
EngineGoldSrc (GoldSource, Previously Named Half-Life Engine)
Microsoft Windows Edit this on Wikidata
Genre(s)First-person shooter
science fiction video game Edit this on Wikidata

Opposing Force returns to the same setting as Half-Life, but instead portrays the events from the perspective of a U.S. Marine, one of the enemy characters in the original game. The player character, Adrian Shephard, is sent in to neutralize the Black Mesa Research Facility when a incident causes it to be invaded by aliens, but quickly finds that the Marines are outnumbered by enemies. The game is notable for featuring an entirely new alien faction called Race X that is never seen anywhere else in the series, as well as new weapons and mechanics like commanding squads of marines and using night-vision instead of a flashlight.



Adrian Shephard


Adrian Shephard is the Protagonist and the Main Character in Half-Life: Opposing Force tasked with neutralizing Black Mesa after a resonance cascade, but now has to escape and team up with Other Employees after Adrian’s Designated helicopter Crashes.