Story: You're Alexander Shepard - Corporal and a soldier of the Hazardous Environment Combat Unit. You don't know exactly what's going on. But orders came in to pack up everything and head out for a highly classified mission. The destination - Black Mesa research facility. Nobody knows for sure what has happened down there but you will find out soon enough.

This map pack plays during the events of Half-Life, Blue Shift,Op4,Decay.

Mod features:

- 16 maps
- few custom voices
- many model props
- story plot based upon Op4, Blue Shift, Hl1, Decay
- Op4 music +1 custom music track
- Approximate game play time between 1 to 2 hours.
- Op4 entities
- Additional NPC custom skins

Mod download - exclusively hosted on:

Mod download

or here on moddb itself.

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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

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Military Duty - Low Definition Pack

Military Duty - Low Definition Pack

Skin Pack 4 comments

Low Definition Pack for Military Duty mod! Hope you enjoy.

Black Mesa Helicopter set (reskinned)

Black Mesa Helicopter set (reskinned)

Vehicle Skin 4 comments

To my knowledge the first set of model props ever released which contains Helicopters in model format based upon the Black Mesa Research Facility. The...

Military Duty Version 1.0.1 Final

Military Duty Version 1.0.1 Final

Full Version 22 comments

This is the final release of Military Duty fixing numerous bugs which popped up during the initial release. I wish everyone fun and advice reading the...

Comments  (0 - 10 of 52)

I want to know something, how you able to spawn zombie with a worker and a second hecu skin? Opposing Force didn't had a releasing SDK so how you do it? Can you please tell me?

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23-down Creator

alialatrach Sub skins are added within the models itself. MDL Modelviewer can decompile models.. In them you can add other files which are basically nothing else than text and picture documents containing the model information and textures.

Half-Life and Opposing Force can unfortunately only support a limited number of skins per model as that's hard coded.

I once had Op4 Grunts containing like 16 different heads. Pity they didn't work. Heads were swapping when they died or played animations. :P

For that amount of heads you indeed need to rewrite parts of the code for the game to allow more than that fixed number of sub models.

Reply Good karma+1 vote

Thanks for the reply. I'll see what i can do.
And one other thing. I enjoy it the mod especialy the last part. Me and my hecu friends must hold the line until the evacuation train arrive, better than escape alone.

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23-down Creator

Glad you liked it. :)

Reply Good karma+2 votes

3 unofficial games have already been ported to the eternal ps2
half life 1
blue shift
I'm anxious, I need a response from you, times have changed 2019 would be ideal port for PS2
a magnificent game exploring the complex black table

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23-down Creator

Port is to Ps2.. I don't mind jonatasv

Reply Good karma+1 vote

running this mod on a Macbook Pro using Steam, i edited liblist.gam so it would work with mac as with all the other mods i've played so far

gamedir "Military_Duty_v1"
game "Military Duty"
startmap "mil_duty1"
trainmap "training"
url_info ""
version "1"
size "96000000"
svonly "0"
cldll "1"
hlversion "1108"
type "single"
mpentity "info_player_deathmatch"
gamedll "dlls/mil_duty.dll"
gamedll_osx "../valve/dlls/hl.dylib" (<----- only new line added)

the intro cutscene works fine, enemies are still in proper spots but there are no soldiers after the intro. the engineer doesn't spawn either, it's like a ghost town :(

I installed it off here ( and followed their directions. I think the directions are wrong though since the HUD display is that of Half-Life & uses a flashlight instead of NVG.

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23-down Creator

Thanks for letting me know about that k2baby. I may add official support for that in the future..

As for the Op4 content missing. Naturally you also need to link to the osx folder for Gearbox.

So best to make a copy of Gearbox.dylib and rename it to mil_duty.dylib and place it inside the folder where those files are stored in within mod folders.

Reply Good karma+1 vote
23-down Creator

You need to make a copy of your opposing force opfor.dylib and copy it into my mod dll folder.

MAC support obviously wasn't something I even considered or thought about.

So the line should read like this: gamedll_osx "../mil_duty/dlls/opfor.dylib"

Not sure whether mil_duty.dll + it's entry in the libist.gam will still be required afterwards or not. Test it out.

Reply Good karma+1 vote

I just realized that the custom voices in the beginning chapter are from Operation Flashpoint: Cold War Crisis.

Ah that brings back memories

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Half-Life: Opposing Force
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Highest Rated (4 agree) 10/10

Well, what can I say. It was a long time after I played a decent GldSource mod set in the Half Life universe. And this one is more than decent. This is epic. From the very start, till it's climatic ending. The story simple: You are a HECU soldier, trying to cover up the whole Black Mesa incident and ending up fighting for your own survival. But, in this mod you can actually see the huge mobilization of the HECU military division (trucks, jeeps, tanks and equipment laying around) and their struggle…

Jun 29 2015 by Thanoshld

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