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Opposing Force is the first official expansion for Half-Life, developed by Gearbox Software under the supervision of the original creator Valve. The storyline of the base game is interwoven into the add-on, as players take on the role of Corporal Adrian Shephard, one of the soldiers sent to the Black Mesa facility to "clean up" the incident and silence any witnesses.

Shephard never reaches his final destination, though: his helicopter is shot down, his squad killed, and he finds himself in a battle for survival against the invading aliens.

Opposing Force takes place concurrently with Half-Life, and Shephard will witness some of the same events (though from a different perspective) and visit some of the same places as Half-Life's protagonist Gordon Freeman did in the original game. The add-on uses the same style of storytelling as Half-Life: everything is seen from the eyes of the protagonist.

The expansion pack consists of 12 new interconnected "levels". There are new weapons and new enemies: Zombie Grunt, Pit Drone, Shock Trooper and Voltigore, plus some new boss creatures.

Another new feature is the ability to command AI-controlled teammates, belonging to different classes: standard grunts and heavy gunners can be called upon for support fire, engineers can cut through doors and medics can restore lost health. Some areas of the game can only be completed with the squadmates' help.


Half-Life: Opposing Force Windows Shot from the "Full Metal Jacket"-style boot camp level
Half-Life: Opposing Force Windows On Xen again...
Half-Life: Opposing Force Windows Loading screen, note that Gordon Freeman now is switched to a bad-ass marine.
Half-Life: Opposing Force Windows Toxic wastes usually require jumping-on-the-crates tactic.

Promo Images

Half-Life: Opposing Force Screenshot
Half-Life: Opposing Force Screenshot
Half-Life: Opposing Force Screenshot
Half-Life: Opposing Force Screenshot


Alternate Titles

  • "OF" -- Common abbreviation
  • "Hλlf-Life: Opposing Force" -- Cover / in-game title
  • "ハーフライフ: オポージングフォース" -- Japanese spelling

Part of the Following Group

User Reviews

Another facet of a gem. Windows Ray Soderlund (3608)
The Making of Adrian Shepard Windows vicrabb (7291)
True example of better add-on sequel than the original. How's that possible? :) Windows MAT (207136)
That's what an expansion should be! Windows JudgeDeadd (26596)
Isn't it nice to become the enemy for once? Windows Katakis | カタキス (41128)
Opposing Farce is more like it... Windows MasterMegid (902)
Redfines what an expansion pack should be! Windows jeremy strope (171)
Sweet game. Better than the original. Windows The Big Ragu (3)

Critic Reviews

GamePro (US) Windows Nov 24, 2000 5 Stars5 Stars5 Stars5 Stars5 Stars 100
Daily Radar Windows 1999 4 Stars4 Stars4 Stars4 Stars 100
Gamer's Pulse Windows 1999 94 out of 100 94
GameSpot Windows Nov 24, 1999 9 out of 10 90
Vgames Windows Feb 10, 2000 88 out of 100 88
PC Joker Windows Jan, 2000 88 out of 100 88
GameSpot (Belgium/Netherlands) Windows Dec 13, 1999 86 out of 100 86 Windows Dec 02, 1999 17 out of 20 85 (UK) Windows Dec 02, 1999 7 out of 10 70
Computer Games Magazine Windows Dec 06, 1999 3.5 Stars3.5 Stars3.5 Stars3.5 Stars3.5 Stars 70


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Installing Opposing Force automatically patches Half-Life to version The patch not only fixes several bugs, but adds the multiplayer mode Team Fortress Classic.

German version

There are a number of changes in the German version:
  • All blood and gore effects after hits against enemies or the player were removed.
  • If a human non-enemy is killed, he does not die but sits on the floor and shakes his head.
  • In multiplayer mode, the human skins (except assassin) were replaced with the "Helmet" skin.
A detailed list of changes can be found on (German).


  • In original Half-Life, when you played the scientist Gordon Freeman, you jumped into some huge generated portal to reach the alien world. In this game, when playing military corporal Sheppard, you actually see Freeman how he jumps into that portal, and then come to the same point only the portal crashed before you manage to follow, but you exterminate what's left of the flying aliens around, though.
  • The game contains easter eggs which reference DOOM II, The Beating of a High School Janitor song by Adam Sandler, David Michael Mertz and James Bond. Detailed information about how to reach them can be found in the tips & tricks section.


  • GameStar (Germany)
    • Issue 03/2000 - Best Add-on in 1999
Information also contributed by -Chris and Sciere.

Related Web Sites

  • Hints for Opposing Force (The solutions are given gradually in this hint file so other parts of the game are not revealed until you need them.)
Contributed to by Alsy (18652) and MAT (207136)