Obsidian Conflict is a cooperative multiplayer modification set in the Half-Life 2 universe.
It features a large amount of new gameplay features on all-new maps specially designed for the mod with focus on cooperative gameplay, as well as over hundred user-made maps following the same formula.

In addition to that, You're able to play through vanilla Half-Life 2 all the way up to Episode 2, as well as experimental support for cooperative Half-Life: Source play.

Key features:

- All Source engine Half-Life series games playable in co-op online (Half-Life: Source, Half-Life 2, Lost Coast, Episodes 1 & 2)
- A large set of included custom maps, some in the form of classic combat & teamwork puzzles and others offering extraordinary new gameplay experiences such as cooperative farming and fishing
- New weapons, including dual Uzis, Medkit, Sniper Rifle, the Alyxgun, the Tau Cannon, deployable Manhacks, as well as support for scripted weapons allowing use of weapons from Counterstrike and Day of Defeat Source
- New NPCs, including many from the original half-life such as a fully-functional ichthyosaur, as well as a working mortarsynth from HL2
- Special merchant NPC and related entities, offering gameplay where players can spend points from their score to purchase weapons and map-specific objects
- Many co-op related features, such as a server-side lives system, hud waypoints, player locator, attention & medic calls, and map objectives, as well as players' inventory carrying over between level transitions
- Great support for community mappers, including features like the mapadd system to easily edit existing maps without having to recompile them, as well as tutorials and prefab examples for all of OC's new entities and features
- Support for custom playermodels and custom colorizations on weapons and hud elements

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WIP Map OC HUD Mockup Military Tablet

Hello everyone, we’d just like to inform you that our community member jfm created an automatic mountfix installer, big thanks to him!

Please note that it is not created by the OC team and we do not take responsibility for any damage it might do to your system.

It comes in 2 versions, one with a full OC installer included and one with just the mountfix.
Please make sure .NET Framework 4.5 is installed and you're running at least Windows Vista, XP is not supported.


Zipped versions, for those that want them:

So how does it work and what does it do?

  • Before installing, make sure you have SDK Base 2007 and all the games you want to mount installed and fully working in Steam.
  • Now, you either just run the full installer, which will execute the mountfix.exe once it’s done installing OC, or
  • place the mountfix. exe in your existing Steamapps/Sourcemods/Obsidian folder, run it, either type "client" or "server" and hit enter.

The server part installs and configures a basic server config setup for first time server admins and requires a login.
The login is required for SteamCMD and is NEVER stored.

For more information and credits, check this Readme.

Please note that the mountfix can take a long time to complete and it may seem like nothing is happening at all. Don’t close the window, this is normal! The window will close once it’s done.

What the mountfix does is it first scans for your installed games, extracts the content from their depositories and then creates symlinks in your steamapps\common\Source SDK Base 2007 folder.
This process is very hard disk-heavy and thus can take a long time to complete.

This also doubles the disk space taken for each installed, mountable game since the files now exist twice; once in the normal Steam depositories and once as unpacked files which OC can read.

We are still working on a proper hotfix, but until then, this is a good stop-gap measure if you or your friends want to get into some OC action right now.

Breaking the silence

Breaking the silence

1 year ago News 19 comments Report

We have a hotfix in the works to address some of the problems that have been plaguing OC the last few months, it will fix the now-broken mounting system...

Obsidian Conflict Devblog Video #1

Obsidian Conflict Devblog Video #1

3 years ago News 25 comments Report

We've been quiet for too long again, heck, we almost could have reused the news post from last Christmas by now. So, to break the silence, we present...

Merry Christmas!

Merry Christmas!

4 years ago News 7 comments Report

We wish you all a Merry Christmas and hopefully a happy new year from all of the OC Team! While we're at it we would like to give you some news about...

New team members, next stop: Steamworks!

New team members, next stop: Steamworks!

4 years ago News 19 comments Report

We have been somewhat quiet the last few months, but we hope to change that. From now on we will try to make more frequent news posts to keep people updated...

Obsidian Conflict is a cooperative multiplayer modification set in the Half-Life 2 universe. It features a large amount of new gameplay features on all-new maps specially designed for the mod with focus on cooperative gameplay, as well as over hundred...
OC 1.35 Unofficial Mountfix (Full installer)

OC 1.35 Unofficial Mountfix (Full installer)

2 months ago Full Version 2 comments

Full installer, installs 1.35 plus hotfix and does the mountfix automatically. For detailed instructions, check the mountfix post. (File updated 07.08.2015...

OC 1.35 Unofficial Mountfix (Mountfix only)

OC 1.35 Unofficial Mountfix (Mountfix only)

2 months ago Patch 0 comments

Stand-alone mountfix, for existing installations. For detailed instructions, check the mountfix post. (File updated 07.08.2015 19:00)

Obsidian Conflict 1.35 Hotfix #1 (Client)

Obsidian Conflict 1.35 Hotfix #1 (Client)

3 years ago Patch 13 comments

For mod client only, not required on dedicated servers. (Requires 1.35 Full.)

Obsidian Conflict 1.35 Hotfix #1 (Server)

Obsidian Conflict 1.35 Hotfix #1 (Server)

3 years ago Server 1 comment

For dedicated servers only, DO NOT INSTALL ON MOD CLIENT!! (Requires 1.35 Full.)

Obsidian Conflict 1.35 Full Installer

Obsidian Conflict 1.35 Full Installer

5 years ago Full Version 96 comments

Note: The playermodel installer is currently unavailable. Just hit "Cancel" during that dialog pop-up and the installer will continue properly.

Obsidian Beta 1.34 Full

Obsidian Beta 1.34 Full

6 years ago Full Version 28 comments

Note: Only choose "Install client only" or the mod wont install properly.

Post comment Comments  (60 - 70 of 737)
TheFadedDarkness Sep 23 2013 says:

Anyone else getting this error..... CFileSystem_Steam::Init() failed: failed to find steam interface

+1 vote     reply to comment
OverTheGun Oct 16 2013 replied:

Yeah, I had that when trying to run any mod. I fixed it by deleting everything inside the Steam folder, except for steamapps, downloading the Steam installer from their site, and after running it, choosing repair.

I assume you've fixed it or don't care by now, but incase anyone else stumbles by with the same problem, the above should sort it out.

+1 vote     reply to comment
TheFadedDarkness Oct 20 2013 replied:

same error mate.
Thanks for trying though.

+1 vote     reply to comment
Braindawg Sep 17 2013 says:

you guys should release something.

Not like the next version, but like another hotfix to try to keep the playerbase stimulated.

+2 votes     reply to comment
Whitelightning51 Aug 2 2013 says:

Tis dead

-3 votes     reply to comment
Pavol838 Aug 5 2013 replied:

Man you have something wrong in head

+4 votes     reply to comment
Bublgum Jul 7 2013 buried:



-5 votes     reply to comment
Catie㋡(Boxxy) Jul 7 2013 replied:

TESLA posted on the forums: "Nope, we're not dead. It's just that stuff is taking longer than usual, but hopefully it'll be worth the wait."

+10 votes     reply to comment
Whitelightning51 Jul 19 2013 replied:

Wheres this forum i wanna have a look Please.

+1 vote     reply to comment
Humin Jul 20 2013 replied:


+1 vote     reply to comment
Technodude010 Jun 7 2013 says:

It's been quite a while since an update, but I guess people are busy and that ton of work they released screens of is going on.

Just a little word would be nice y'know...

+5 votes     reply to comment
Agent_John May 31 2013 says:

Ok... what is this? I downloaded the mod, installed it and started to play it. But practically EVERY server i go on is to do with either FISHING or FARMING. WHAT the **** is this?! I thought this was a Half Life 2 co-op rather than a freaking simulator type of thing... am i missing something here??? All i see is people doing the same maps over and over, Harvest and that Diving map. I am really confused.

+4 votes     reply to comment
evsey7 Sep 13 2013 replied:

Go f*cking play synergy if you want coop.

-4 votes     reply to comment
Humin May 31 2013 replied:

People tend to find those maps more fun.

+6 votes     reply to comment
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Official Page
Release Date
Released 2008
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618 votes submitted.

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Highest Rated (9 agree) 9/10

Nice option, almost perfect co-op mod and with a lot more options than Synergy. You should try it. :D

Dec 3 2010 by Killer_man_1996

First Person Shooter
Multiplayer & Co-op
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