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!

Image RSS Feed Screens
Living quarters outbound Hazard Course Concepts

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

Operation Black Mesa DEV.BLOG: Advanced AI

Operation Black Mesa DEV.BLOG: Advanced AI

2 years ago News 52 comments

Our team proudly presents our new AI system we implement for our NPCs. Check out this for more information and a video.

Greenlight incoming for Blue shift and Opposing force remakes !

Greenlight incoming for Blue shift and Opposing force remakes !

2 years ago News 29 comments

Few words about Greenlight, progress and more about Guard Duty and Operation Black Mesa.

Guard Duty and Operation Black Mesa- MOTY update

Guard Duty and Operation Black Mesa- MOTY update

2 years ago News 12 comments

Tripmine studios decided to give you some new media from Operation Black Mesa and Guard Duty. Hope you enjoy them.

Report for duty

Report for duty

3 years ago News 15 comments

Small update and invitation to our multiplayer session in the original Opposing Force: Multiplayer.

RSS Feed Downloads
Elevator to hell

Elevator to hell

4 years ago Music 4 comments

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



4 years ago Music 3 comments

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

Sigh of relief

Sigh of relief

6 years ago Music 6 comments

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

Post comment Comments  (30 - 40 of 1,468)
TheMuffinMan2360 May 4 2015 says:

Which mod do you put more work/time into as a group? Will this affect the development speed of Guard Duty?

+1 vote     reply to comment
MR.sugar Creator
MR.sugar May 6 2015 replied:

A lot of assets is shared, so it's more about the level designers. We try to dedicate our work to both projects equally.

+2 votes   reply to comment
Mr_Walrusman Apr 29 2015 says:

When will we be getting a update?

+1 vote     reply to comment
MR.sugar Creator
MR.sugar May 3 2015 replied:

There is currently no ETA for an update. We just work behind the curtain. for now.

+1 vote   reply to comment
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
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Guard Duty
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