Half-Life: Opposing Force is an expansion pack for Valve Software's science fiction first-person shooter video game Half-Life. The game was developed by Gearbox Software and published by Sierra Entertainment on November 1, 1999. Opposing Force is the first expansion for Half-Life and was first announced in April 1999. Randy Pitchford, the lead designer on the game, later noted that he believed Gearbox was selected to develop Opposing Force because Valve wanted to concentrate on their future projects. Over the course of development, Gearbox brought in a variety of outside talent from other areas of the video games industry to help bolster various aspects of design. 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.

Image RSS Feed Latest Screens
Gargantua Dam Poor Scientist Opposing Force
Blog RSS Feed Post news Report abuse Latest News: Military Duty - Mod Release

About Military Duty with 2 comments by 23-down on Jun 28th, 2015

Howdy folks. Today I'm proud to announce you the release of a new Half-Life: Opposing Force mod (Op4 not required) It is a map pack that consists of 15 maps in decent quality. The mod features custom skins, few new voice lines as well as rather balanced game play. There're still few minor glitches in it which eventually may get addressed in a future patch but nothing serious. The mod is completely playable.

Military Duty

Story wise the map pack plays during the events of the official Hl1 games , Op4, Blue Shift, Decay & the original Hl with Freeman. So nothing fancy here.

Anyway for those unfamiliar with this project so far. Let me introduce it a little bit for you. This mod has been a little side project of mine that I started several years ago but just recently I finally managed to return for it and to finish it. Keep in mind though that this is my first mod release ever for Half-Life. So I'm hoping for many comments from you people either here or on the site that hosts my mod. Positive feedback as well as constructive criticism would be most appreciated.

Special thanks go to all of you my followers and my team mates which helped me on this package as well as my beta testers and everyone else who was somehow involved on this project. But enough talking. I'm sure each one of you would like to play it now.

Important: In it|s current state the mod is not fully compatible with the old WON version of Half-Life. Please keep that in mind. I suggest playing it on steam only.

So here you go:

Download here

Media RSS Feed Latest Video
Downloads RSS Feed Upload file Latest Downloads
Opposing Force: Source

Opposing Force: Source

Jun 12, 2015 Demo 1 comment

Ok before i say anything about this i need to say this: DO NOT SAY THIS: AW HECK YA ITS OUT!!! Its not out its just what i made so far OH that reminds...

Half-Life: Opposing Force FGD for Jackhammer

Half-Life: Opposing Force FGD for Jackhammer

Jan 3, 2015 Mapping Tool 2 comments

This FGD file modified for the Half-Life: Opposing Force enables the visualization of models (weapons, enemies, items ...) in Jackhammer editing screen...

Half-Life: Opposing Force SP Map fixes patch

Half-Life: Opposing Force SP Map fixes patch

Dec 14, 2014 Patch 3 comments

Contains bug fixes for various map for Half-Life: Opposing Force - single player. To note that the structure of the maps isn't changed at all , only entities...

Half-Life: Opposing Force


Oct 21, 2014 Improvement weapons models Full Version 0 comments

Full version. Improvement weapons models for Opposing Force. Full version. Improvement weapons models for Opposing Force. Full version. Improvement weapons...

Sledge Alpha Build

Sledge Alpha Build

Aug 19, 2014 Half-Life Mapping Tool 5 comments

Sledge is a completely free and open-source replacement for Valve's Hammer Editor, with a focus on compatibility with both Goldsource and Source engines...

Half-Life Dreamcast Strategy Guide

Half-Life Dreamcast Strategy Guide

Jul 3, 2014 Half-Life Guides 2 comments

A Strategy Guide for the Half-Life Dreamcast version was written but never released. I have updated it on Moddb because it's not sold anywhere! It can...

Post comment Comments  (20 - 30 of 72)
Baphomet‪ May 6 2012, 11:02pm says:

I prefered this expansion more than the base game, lol.

+8 votes     reply to comment
ShadowFear Apr 11 2012, 7:53pm says:

I found the Opposing Force CD yesterday. I put it in the cd player for my car and there's absolutely nothing like driving around to this song.

Youtu.be It just screams "KILL!"

+4 votes     reply to comment
Dr.Goupyl Online
Dr.Goupyl Dec 23 2011, 5:33am says:

The best expansion ever made.

+4 votes     reply to comment
Garyn Dakari Oct 1 2011, 6:41am says:

Just finished HL1, HL:OF, and HL:BS.

HL was near perfect in my mind, 10/10 all the way.

OF added some fun new weapons and gameplay mechanics, but almost nothing to the story. And the main character and villain just seemed to be copies of the ones from HL. I liked that one boss fight though, where you had to turn on the Gearbox, activate the Steam vents, and turn the Valve to kill the beast :P 8/10

BS didn't add any new gameplay or weapons, which was slightly annoying, but it made sense. It cleared up a few things about the story which was good, and the Gordan cameos were pretty funny. It was also really short and REALLY easy. I didn't ever die against an enemy in the whole game, and it only took 2 hours to play. And, without spoiling anything, I thought the ending was kinda lame. I'd give it a 7/10

All in all, I loved HL, and liked the expansions. I'll call HL a "Must play" and recommend the expansions if you like HL.

Haven't played HL2 yet, so no rating on that ;)

+2 votes     reply to comment
E3Pointman Apr 18 2011, 6:03pm says:

I love this Game , i just love it!!!!Ahhh good memories :P

+2 votes     reply to comment
AmaroqDricaldari Apr 10 2011, 9:28am says:

I want someone to make the LongJump Module useable in Half-Life 2, GMod, and Half-LIfe Opposing Force. I am starting to get annoyed that nobody has done that yet.

+1 vote     reply to comment
notasinglenamedperso Oct 29 2011, 9:06pm replied:

They cannot do it for HL2 or Gmod because that is on the source engine and that would be porting and if they did port it it would be illegal and it wouldn't work. For opposing force you do not need to download anyhting just when your in the main menu open the console and type "sv-cheats 1" without the quotes and load a level and then open the console again and type "give item_longjump" without the quotes. it will automaticaly give you hl1's longjump and you can use it.

-1 votes     reply to comment
RangerC Mar 19 2011, 7:23am says:

OP4 + Joebama's server = maximum WIN

+4 votes     reply to comment
sasasa Dec 27 2010, 9:01am says:

anyone interested in making new/ high quality drill instructor, 9mm, 9mmAR,.. And all of the others?
don't mention about the redux
oh, and HD map textures???

+1 vote     reply to comment
JrComissarValvatorez Dec 30 2010, 8:07am replied:

Right now I'm just crossing my fingers and hoping Opposing Force is the next thing Richard does after Half Life for his Ultra definition packs.

+1 vote     reply to comment
Post a Comment
click to sign in

You are not logged in, your comment will be anonymous unless you join the community today (totally free - or sign in with your social account on the right) which we encourage all contributors to do.

2000 characters limit; HTML formatting and smileys are not supported - text only

Half-Life: Opposing Force
Gearbox Software
Send Message
Release Date
Released Oct 1999
Game Watch
Track this game
Community Rating



238 votes submitted.

You Say


Ratings closed.

Highest Rated (4 agree) 10/10

The campaign is almost as good as HL's but the multiplayer is just the icing on the cake, Oh but the the cake is lie... oh well.

Nov 21 2010, 10:17am by X-LAyer2

First Person Shooter
Single Player
Half-Life: Blue Shift
Half-Life: Blue Shift Single Player First Person Shooter
Half-Life: Decay
Half-Life: Decay Multiplayer First Person Shooter
Required to play
Half-Life Single & Multiplayer First Person Shooter
Embed Buttons

Promote Half-Life: Opposing Force on your homepage or blog by selecting a button and using the embed code provided (more).

Half-Life: Opposing Force Half-Life: Opposing Force
Half-Life: Opposing Force
Last Update
2 weeks ago
142 members