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 Report abuse Latest News: 2014 Kickoff Update

21 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

Media RSS Feed Latest Audio
Downloads RSS Feed Latest Downloads
Elevator to hell

Elevator to hell

Jun 15, 2011 Music 1 comment

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  (70 - 80 of 1,405)
papatub154 Oct 21 2013, 2:32am buried:


is there any way we can have the hands? like a demo maybe just to replace the default gordon hands in Black Mesa. i LOVE black Mesa but i dont wanna be a scientist anymore.

-7 votes     reply to comment
Crypt Oct 24 2013, 10:34pm replied:

What is up with people asking unreleased mods for their assets? I don't get it.

+5 votes     reply to comment
Guest1982 Oct 18 2013, 5:27am says:

This mod will be awesome!

+4 votes     reply to comment
alucard1k Sep 14 2013, 10:59am says:

Greenlight only for OBM and not for Guard Duty or is GD integrated in the OBM mod?

+3 votes     reply to comment
afterwars Sep 14 2013, 1:08pm replied:

There will be a separate Greenlight page for GD later on, at the moment the focus is on OBM.

No, GD is not part of OBM.

+4 votes     reply to comment
Guest Aug 24 2013, 1:59pm says:

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Guest Aug 18 2013, 4:50pm says:

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walton Aug 10 2013, 12:03pm says:

this is very interesting. I will follow this till its completion

+6 votes     reply to comment
KCKI113R Aug 8 2013, 2:14pm says:

Hey guys, will you add Kleiner, Eli and Magnusson to the later chapters of Guard Duty? I'm glad Black Mesa did that, but will your team do that? (BM failed with Magnusson, he was supposed to be included, plus if you add them it will add a sense of continuity between the Half Life games and it will allow you to extend the ending sequence by making 1 more person go through (more enemy encounters could also be added there))

+2 votes     reply to comment
Crypt Aug 9 2013, 12:28am replied:

When do Kleiner, Eli and Magnusson make an appearance in Blue Shift?

Also, BM didn't fail with that, Magnusson was never confirmed as having made an appearance.

+2 votes     reply to comment
KCKI113R Aug 9 2013, 9:01am replied:

Actually, in episode 2 he said "Oh and Freeman, if you pull this off, I might just forgive you for that dabacle at Black Mesa. You know the one I mean. Involving a certain microwave casserole," and he is referring to the microwave scene in Half Life, near the beginning. It also states he was a character there in the HL wikia. And Kleiner, Eli and Magnusson can be added in the "Focal Point", "Power Struggle", "A Leap Of Faith" and "Deliverance". They could be the replacement for Simmons and Walter Bennet because they are just generic people. It also, as I said, adds a sense of continuity between the games and helps explain better how they all came "in touch" after the resonance cascade.

+1 vote     reply to comment
MR.sugar Creator
MR.sugar Aug 9 2013, 11:19am replied:

We don't plan to replace these cahracters. As for magnusson, maybe it was his casserole, but it doesn't mean he was present in the room. Maybe he put it into microwawe and go somewhere else in the mean time ;)

+4 votes   reply to comment
KCKI113R Aug 9 2013, 3:56pm replied:

Okay. You should at least give Harold, Walter Bennet and Simmons different models from the rest of the scientists to make them feel more important and memorable

+7 votes     reply to comment
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