You are Barney Calhoun, a security guard at the Black Mesa Research Facility. Unknowingly to you, the next few hours of your shift will change your life forever...
Re-live the exciting adventure of Blue Shift on the award winning Source Engine and prepare for the shift of your life!
Welcome to Guard Duty.


- As a total conversion mod, Guard Duty aims to be composed of entirely custom content
- All original maps re-created and re-envisioned for better realism and gameplay.
- Some maps are enlarge/extended to create a more lengthy and immersive game.
- Improved AI, making enemies smarter and even more dangerous than ever before.
- More enemy encounters to keep the action fresh.
- Scripted scenes with all the original Blue Shift characters to help bring the story to life.
- Textures and models that will push the limit of the Source Engine, to bring you as much artistic detail as possible.
- All new voices, sounds and music.
- Multiplayer, which may (or may not) contain various game modes.

And much more!

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Living quarters outbound Hazard Course Concepts
Blog RSS Feed Post news Report abuse Latest News: 2014 Kickoff Update

27 comments by Uphys on Mar 29th, 2014

Welcome to our first media update this year!

Read Full Article.

Multiplayer Beta Release Q1 2014 Cancelled

Our plan to bring you the multiplayer beta of Operation Black Mesa early this year didn't work out, regrettably. Several factors and circumstances forced us to completely keep it under the hood until further notice.

Multiplayer Progress

Multiplayer will feature classic maps such as Yard, Crossfire and Boot Camp as well as brand-new ones like Deptcharge and Gambit from day 1.
Currently in development: CTF mode and weapon placement.


Singleplayer Campaign

Development is running smoothly; those NPCs aren't going to animate themselves though! If you're interested in joining our team, check out the jobs page where you can find all positions currently open. We look forward to welcoming you on board!

Pit Worm's Nest

Remember Guard Duty (Blue Shift: Source)? We're making solid progress here too:

Living Quarters Outbound

OBM: The Video Game?

We've been given the option of developing our projects as full indie titles to be sold on Steam!
This opens up a whole lot of attractive possibilities to consider; however no decision has been reached yet as to this matter.

Alien Controller

M1A1 Tank

Thanks for your support in making all of this possible!

Until next time,
Tripmine Dev Team

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Elevator to hell

Elevator to hell

Jun 15, 2011 Music 4 comments

An example from our soundtrack. This track is made by "Becket007".



Jun 15, 2011 Music 2 comments

An example of Xen track. This track is created by 8BitLord.

Sigh of relief

Sigh of relief

Oct 16, 2009 Music 6 comments

An example from our soundtrack. This track is made by "Mordekai"

Post comment Comments  (30 - 40 of 1,462)
Mr_Walrusman Apr 14 2015 says:

Is the game dead? If not I suggest you should make a update, we haven't gotten one for a year.

0 votes     reply to comment
staffssuckshit May 9 2015 replied:

This mod will not dude for sure.

+1 vote     reply to comment
MR.sugar Creator
MR.sugar Apr 20 2015 replied:

No, we are not dead..

+7 votes   reply to comment
Mr_Walrusman Apr 23 2015 replied:


0 votes     reply to comment
Guest Apr 22 2015 replied:

This comment is currently awaiting admin approval, join now to view.

Petereverett Feb 24 2015 says:

How can you get a permission of valve? There is a guy want to know that. Please answer me.

+1 vote     reply to comment
Mr_Walrusman Apr 23 2015 replied:

Valve allowed Black Mesa (a HD remaster for Half-Life 1) to be sold so they should allow this too.

+1 vote     reply to comment
redyoshi8300 Jun 22 2015 replied:

This project was already approved on the Steam Green Light, so that might mean something on the store front.

+1 vote     reply to comment
Head_Humpers May 1 2015 replied:

Actually Half-Life Blue Shift and Half-Life Opposing Force were both made by Gearbox Software, Valve hardly did ****. All the hard work was Gearbox Software.

+1 vote     reply to comment
Mr_Walrusman May 7 2015 replied:

And your point is? Valve paid them to do it, it wasn't fan made like this, the property would still belong to Valve. And besides that, the Half-Life franchise belongs to Valve and they do what ever with it.

+1 vote     reply to comment
r21d21-the-damager Mar 12 2015 replied:

they are just ok with it

+2 votes     reply to comment
r21d21-the-damager Feb 24 2015 says:

would you mind adding iron sights?
to this and obm?

-1 votes     reply to comment
MR.sugar Creator
MR.sugar Mar 3 2015 replied:

We do not plan to add ironshights.

+1 vote   reply to comment
r21d21-the-damager Mar 3 2015 replied:

would be nice though

-4 votes     reply to comment
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