
Rather, it is an "extension" of Half-Life and, as such, requires that you have the original Half-Life.

In Half-Life, the player takes on the role of Gordon Freeman, a scientist involved in an accident that opens an inter-dimensional portal to the. While the game offers a new episode, it is not a sequel to Half-Life. Opposing Force is set in the same location and timeframe as that of Half-Life, taking place at a remote New Mexico laboratory called the Black Mesa Research Facility. Half-Life: Opposing Force offers new weapons, both military and alien, new levels, new enemies and a new multi-player experience. Left stranded, dazed and confused, you'll need to work with those you were sent in to "contain." A few squads of military personnel are still alive within the complex as well and you'll need their help to escape alive. However, before you are given your orders, something goes horribly wrong and your whole platoon is killed. Your mission? Silence Gordon Freeman and his fellow scientists. In Half-Life: Opposing Force, you play the other side: Cpl.

In Half-Life, you were Gordon Freeman, a scientist struggling to escape the horrific facility.
