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 (40 reviews) - 95% of the 40 user reviews in the last 30 days are positive.
Very Positive (1,961 reviews) - 94% of the 1,961 user reviews for this game are positive.
Release Date: Dec 5, 2014

Sign in to add this item to your wishlist, follow it, or mark it as not interested

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 (92)

February 24

Lambda Wars 3.01b Update

Hello, strategists!
We have released an update. Update version 3.01b (previous 3.01a).

Lambda Wars Update 25 February 2017 (3.01b)

  • Error model inside combine bunker
  • Tutorial now works properly
  • Shieldgen no longer requires power in Overrun
  • Fixed crash caused by spamming combine balls

  • Rebel CPU now builds junkyards near scrap
  • they are now more aggressive early game

  • Rescaled price for veterans by a bit
  • Reduced health for veterans to 120 (from 180)
  • Increased crossbow damage from 100 to 160
  • Increased crossbow explosive bolt damage from 100 to 240
  • Partisans with molotov and partisans with smg now share the same passive "Revolutionary Fervor"
  • Metropolice with pistols now require additional 1 power for production.

  • Optimized particle effects by reducing max particle count for some particle effects

  • Modified mortar effect a bit.

That's that.
If you have any questions, please leave them here or ask us directly at our Discord channel:


14 comments Read more

February 22

Status Update; 7 and 8

Hello everyone,

I hope this message finds all of you well. I only just recovered from a massive flu and I can finally start worrying about things again that surpass mild brain activity.

So, I finally come bringing you the news you want, and my apologies for the delay again.

I want to start today off by a topic I find of grave importance which is...

Our team size.

As you all know I went on board this team in the full knowledge the team scales are unevenly balanced. With an abundance of mappers, and our only coder getting snowed in on occasion, I feel we cannot develop this game in the manner and speed that I'd like. While I'm not asking for an update every week, the alternative now is once every three months, which is far from ideal, right?

So that's why we call to you!

The team behind this game is always looking to fortify its position*, and we're looking to have several posts filled, of which a couple are;
  1. Social Media Editors - With the recent restructure of how the team looks, we've found ourselves open to people who want to help us fortify our Facebook, Twitter and any other pages we own for our product.
  2. Discord Staff - We start all of our moderative staff out at Discord moderator level, and we're always looking to expand. From Discord Moderator it's very well possible you grow into a prominent community role.
  3. Public Relations and Management - Mostly the people assisting me with setting things up for public relations, and also assisting me with minor management issues within the project.
  4. Graphical Experts - We're looking for some volunteer folk who have a knack for various photo-manipulation programs to assist us in creating artwork that are for a variety of goals.

If any of these positions speak to you, feel free to drop me an add on Steam, or contact me on Discord under the name Songbird#2160. I look forward to speaking to all interested folk! No need to send a full resumé, a chat will be sufficient for me.

* ALL positions are volunteer only.

I feel I've droned on enough about this now, let's move on...

Development progress
It's a quiet week, and nothing much to report, other than that everyone is still working hard (if they're not sick, that is), and we've been mostly working at fixing and addressing leftover bugs from the new update. If you've got a bug, feel free to report it in our Steam forums, or on the Discord.

With that, I want to say I've been mostly out of the loop all weekend due to the flu hitting me hard, and unfortunately put me out of business ALL week last week, and the weekend, so I apologise for the short amount of information.

With best;
Songbird & Team.

11 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 (40 reviews)
Very Positive (1,961 reviews)
Review Type

Purchase Type


Display As:

(what is this?)
1,084 reviews match the filters above ( Very Positive)
There are no more reviews that match the filters set above
Adjust the filters above to see other reviews
Loading reviews...