Lambda Wars is a free standalone multiplayer Source Engine modification set in the Half-Life 2 universe that brings the war between mankind and their brutal Combine overlords to a traditional real-time strategy (RTS) setting.
User reviews:
Very Positive (49 reviews) - 95% of the 49 user reviews in the last 30 days are positive.
Very Positive (1,926 reviews) - 94% of the 1,926 user reviews for this game are positive.
Release Date: Dec 5, 2014

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Community-Made Mod

This is a free community-made modification for Alien Swarm set in the Half-Life 2 universe.

Click here to learn more about mods on Steam.

Install Lambda Wars Beta

Free Alien Swarm Mod


Recent updates View all (85)

January 16

Thanks for betatesting!

Hey, Strategists!

A lot of you joined us tonight and played with us on the developer's build, or were just there for a friendly chat.

In any event, we want to thank you so much for helping us out tonight, and we hope you've had good fun!

If you were one of the betatesters, you've been granted a badge. A small thanks to the following people;
Doggo of Metaphysics,
Cpt Jack,
Dr Mad,
An obscure loss and
Rick Guyface

For betatesting and helping us find middleground!

Thanks a bunch folks!

If you have been part of the betatesting, or occurred bugs, feel free to report them in the form available on Discord.

See you all Sunday!

~Songbird, JJ, ProgSys and Pandango.

12 comments Read more

January 15

General Update (15th of Jan) & Tournament Information

Hello strategists!

It's been a hell of a first week, and the team behind Lambda Wars has been absolutely amazing in helping me find my way around! I've evolved into Project Manager, rather than just Community Manager. I run this position with the close cooperation of Mr. Darkness and Pandango, whom I hope to work with and to steer us in a new, reinvigorating path, and motivation and morale has risen once more within the team. I'm happy to say I'll have plenty to speak of in the development-oriented update of the 22nd.

First things first... What changed over this week?

Well, I'm not sure where to start.

First of all, like I mentioned, the official title I'm holding has changed, with the consent of the Development Team. I've been named Project Manager, and I mostly facilitate in day-to-day operations, offering my insight and guidance, and general workflow management. Ontop of that, I've also been allowed to introduce new additions to the team, who I'd like to give a short mention here.

Cole (Brax), kennyrkun and Riekelt are all new additions to our team as Assistant Developers, who are highly motivated to help us progress this Mod as we always intended, so please give them a warm welcome.

Well, that's the team update, let's get onto the real point of the story here!

Today I come bearing joyful news, in which that I - and Hayden - have organised a new tournament, to start at the 10th of February (pending some work, of course.) intended for all large and small communities for Garry's Mod that orient themselves on Roleplay (idea by Hayden), and we've been met by overwhelming responses and enthusiasm. I've made mention of this before, but I want to thank everyone for their input, enthusiasm and consideration in all of this, it's really a big motivation for us!

All tournament information (for as far as decided upon) can be found here.

We hope to see many of you during the live streams and video recordings, and we hope to see a lot of buzz going to be surrounding this event. I speak on behalf of the developers, and the full team when I say we've made great strides this week, and continue to try and do so in the future.

Stay tuned for the 22nd, which is next week Sunday! The much anticipated development update post will arrive then to discuss what we're releasing, what we're working on, and to answer some burning answers and requests from our Community. I can't wait, personally!

Enjoy the rest of your weekend, strategists!
~Songbird & Team.

12 comments Read more

About This Game

Lambda Wars is a free multiplayer Source Engine modification for Alien Swarm set in the Half-Life 2 universe that brings the war between mankind and their brutal Combine overlords to a traditional real-time strategy (RTS) setting. Lead the uprising as a commander of the Resistance or crush the rebellion as an overlord of the Combine, with both factions featuring a full host of units, abilities, buildings, research and defenses. Lambda Wars features full-fledged RTS gameplay and a robust RTS interface and is focused on multiplayer but strategic AI opponents and dedicated singleplayer missions are also included.


  • Classic real-time strategy (RTS) gameplay in the Half-Life 2 world
  • Multiplayer support and game lobby including spectator mode
  • Wide variety of maps for up to 8 human or AI players
  • Play as either Combine or Resistance (and also Antlions in Sandbox mode)
  • Full unit tech tree that allows you to command everything from Manhacks to Striders
  • Full-fledged RTS interface and HUD with everything from minimap and fog of war to unit and production building groups
  • Build production and research facilities to requisition better units and unlock abilities and upgrades
  • Defensive structures, turrets and mines help defend your headquarters and vital resource points
  • Multiple game modes
  • Singleplayer missions, tutorial map and offline AI skirmish mode

System Requirements

    • OS: Windows 7
    • Processor: Dual core from Intel or AMD at 2.8 GHz
    • Memory: 3 GB RAM
    • Graphics: nVidia Geforce 8600GT, AMD Radeon HD2600 or better
    • DirectX: Version 9.0c
    • Storage: 4 GB available space
    • Sound Card: DirectX 9.0c compatible sound card
Customer reviews Learn More
Very Positive (49 reviews)
Very Positive (1,926 reviews)
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