Lambda Wars is now a free standalone mod on Steam: Steam Store (December 2014)

Lambda Wars (formerly called Half-Life 2: Wars) brings the struggle between the human resistance and their Combine overlords to a multiplayer real-time strategy setting. The Lambda Wars beta only requires Alien Swarm installed to play. It features 3 multiplayer game modes: Sandbox, Annihilation and Overrun, showcasing the Rebels and Combine playable factions and a full-fledged RTS interface and HUD. There is also a singleplayer tutorial and a handful of singleplayer missions.

As of December 2014, we have released the game on Steam as a free, standalone mod. This means you DO NOT require Half-Life 2, Alien Swarm or any other Source game to download and play Lambda Wars on Steam.

For questions, comments, suggestions, and support for any of our past or upcoming betas, visit our forums or steam community hub.

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Lambda Wars Update

3 months ago News 16 comments

Last Wednesday we released our biggest update yet! This update includes three new units and two new buildings, many balance changes and improvements.

First off we replaced the Rebel Partisan with an updated version. This unit has two main attacks between which you can switch: throwing molotovs or stinkbombs. Molotovs do light damage at units around the target area, while stinkbombs slow units down. Second we got the new Riot Metro Police, equipped with a shield and stunstick. In offensive mode, this is a fast moving melee unit. Using the station ability you can deploy the unit, generating a cover spot for units behind the metro police.

riot preview

Furthermore we added the Rollermine to the Combine, which you can produce at the also new Mechanical Factory building. The Rebels got a new Offensive building, the Teleporter. Using this building you can teleport units to anywhere on the map, as long as you have vision. A teleportation takes 40 seconds to complete. During this time the units being teleported are unusable and rift is created at the target location, visible to enemies.


The full changelog is:

Gameplay & Balance
* Added Combine Metro Police Riot:
	- Replaces Combine early unit Metro Police with Pistol
	- Equiped with Stunstick and Shield
* Added Rebels Partisan wtih Molotov:
	- Replaces Rebels Partisan unit
	- Autocasting ability Molotov, setting the target units on fire
	- Ability stink-bomb, temporary slowing down the movement of hit units
* Added Combine rollermine: shocks enemy units with a small chance to stun
* Headcrab Canister launcher:
	- Now has three launch abilities for regular, fast and poison headcrabs
	- Reduced Canister health from 550 to 300
	- Increased range from 5000 to 9000.
	- Increased crawl out speed of Headcrabs
	- Spawned Headcrabs roam the map to find enemies
* Added Combine Mechanical Factory building:
	- Builds Scanners, Manhacks, and Rollermines
* Added Rebel Teleporter building
* Infested zombies now roam the map to find enemies
* Headcrabs can now damage buildings.
* BugBait:
	- Increased throw range from 800 to 1000.
	- Increased recharge time from 1 to 30.
	- Increased energy 30 to 50.
	- Uses smaller, faster antlion version.
* Dispel:
	- Increased recharge time from 2 to 3.
	- Increased energy from 30 to 50.
	- Increased range from 800 to 900.
* VortAttack:
	- Decreased energy from 10 to 5.
	- Decreased recharge time from 1.8 to 1.5
	- Decreased damage from 60 to 30.
	- Increased range from 575 to 590.
* Vortigaunt:
	- Increased in combat energy regeneration rate from 1 to 2.
	- Increased speed from 242 to 245.
	- Decreased build time from 48 to 42.
	- Decreased health from 300 to 250.
	- Decreased max energy from 370 to 200.
	- Changed cost from 45req, 50scrap to 50req, 36scrap
* Vortigaunt Den:
	- Decreased scrap cost from 40 to 30.
	- Decreased build time from 54 to 50.
* Manhack:
	- Removed light attribute.
	- Reduced health from 40 to 30.
* Veteran:
	- Requires Steady Position to attack.
	- Added Smoke Grenade ability.
	- Increased range from 870 to 1100.
	- Increased build time from 32 to 35.
	- Decreased health from 210 to 170.
	- Decreased view distance from 1200 to 1000.
	- Increased requisition cost from 45 to 50.
* Saboteur - Removed Smoke Grenade.
* Combine Sniper - Increased health from 110 to 160.
* Hunter - Reduced power cost from 50 to 30.
* Synth Factory - Reduced power cost from 50 to 40.
* Claw Scanner:
	- Mine automatically recharges after being deployed.
	- Mine is uncloaked, health increased from 40 to 100.
	- Mines no longer bounce and roll after being dropped.
	- Mines hop towards enemy.
	- Disabled bullet 2 bonus damage vs creature.
	- Disabled pulse 0.6 damage scale vs creature.
	- Disabled shock 50 bonus damage vs heavy.
	- Disabled shock 0.5 damage scale vs synth.
* Rebel & Combine Barricade - Added 1 extra cover point.
* Improved reliability of Dog Jump ability
* Hunter jump ability: Behaves more predictable and now acts on all Hunters in player selection
* Combine Manhacks can now be build at the Headquarters, with Armory building as requirement
* Replaced Combine Observer by not cloaked, faster and cheaper Scanner unit
* RPG attribute now has reduced damage against medium (-50%) and heavy (-30%) types of units
* Reduce flash ability recharge time from 60 to 25

* Vortigaunt starts at full energy when spawned
* Energy of all units is replenished between waves now

* hlw_synth, hlw_antarctica and hlw_aurora: update scrap points to use small versions
* hlw_thirst: mountains are now impassable and removed (confusing) day/night cycle
* Added: or_village (Overrun mode)
* sp_valley - Combine attack your flag on hard difficulty
* hlw_mine: tweak scrap marker position to fix an issue where engineers could get stuck

UI & Lobby:
* New loading backgrounds;
	- Metrocop loading background by Revvylo
* Show game mode for found online games
* Improved speed of creating or joining a lobby
* Fail to join lobbies on different game version (through friend invites), which would result in not joinable games
* Small performance improvements html UI

Unit Navigation:
* Simplified navigation meshes, preventing several issues and resulting in better performance
* Some unreachable cover spots are now filtered from being displayed

* Ability being cancelled before the player can target something due units dying in the selection
* Unable to place mountable turrets properly on some map spots (hlw_slums)
* Fix units not following a target unit properly after the target unit hold a position or was in cover
* Melee units (e.g. Zombies) not getting close enough to hit buildings 
* Fog of War toggle in Sandbox showing incorrect behavior
* Strider minigun shooting at feet of infantary rather than body
* Rebel rpg attribute not being applied to enemy units, resulting in missing bonus damage against synth type of units (Strider and Hunter)
* Potential exit crash due cleaning up CEF panels
* Fix (online) game lobby empty and unusable upon creation in some cases
* Fix black terrain, only in Simple lighting mode (e.g. Geforce 7 cards)
* Fix checkmark font character not displayed in game lobby on Windows 10

* Add Hungarian translations, provided by Bence Gercuj
* Russian translation updated by Chiffer

teleporter preview

To get Lambda Wars for free, visit our Steam store page:

Lambda Wars Beta HL2 RTS Mod Released For Free on Steam

Lambda Wars Beta HL2 RTS Mod Released For Free on Steam

11 months ago News 8 comments

Our first official Steam release since passing through Greenlight in January!

Lambda Wars Beta 2.3.6 Released

Lambda Wars Beta 2.3.6 Released

1 year ago News 2 comments

Beta 2.3.6 is a collection of bugfixes and small visual and balancing updates to the mod to help prepare for our release on Steam later this year.

Lambda Wars 2.3.5 beta is out. Heading for Steam release, recruiting!

Lambda Wars 2.3.5 beta is out. Heading for Steam release, recruiting!

1 year ago News 5 comments

Beta 2.3.5 is the first TOTALLY FREE release of the mod, not requiring players to own Half-Life 2: Episode 2. Check out its numerous bugfixes, gameplay...

Lambda Wars Beta 2.3.4 Released

Lambda Wars Beta 2.3.4 Released

1 year ago News 1 comment

Beta 2.3.4 is a minor bugfixing and balancing release, with both patch and full releases.

RSS feed Downloads
Lambda Wars 2.3.6 FULL EXE

Lambda Wars 2.3.6 FULL EXE

1 year ago Full Version 15 comments

The newest version you can now get directly on steam, completely free, no other games needed. Install Instructions: 1. Run the Installer and follow the...

Lambda Wars 2.3.6 FULL 7z

Lambda Wars 2.3.6 FULL 7z

1 year ago Full Version 2 comments

Install Instructions: 1. Extract contents into your sourcemods folder (default location: C:\Program Files (x86)\steam\steamapps\sourcemods). 2. Restart...

Lambda Wars 2.3.5 7z PATCH

Lambda Wars 2.3.5 7z PATCH

1 year ago Patch 4 comments

Install Instructions: 1. Extract contents into your sourcemods folder (default location: C:\Program Files (x86)\steam\steamapps\sourcemods) and overwrite...

Lambda Wars 2.3.5 FULL EXE

Lambda Wars 2.3.5 FULL EXE

1 year ago Full Version 6 comments

Install Instructions: 1. Run the Installer and follow the instructions. 2. Restart steam. 3. "Lambda Wars" should now appear in your games list. If you...

Lambda Wars 2.3.5 FULL 7z

Lambda Wars 2.3.5 FULL 7z

1 year ago Full Version 0 comments

Install Instructions: 1. Extract contents into your sourcemods folder (default location: C:\Program Files (x86)\steam\steamapps\sourcemods). 2. Restart...

Lambda Wars 2.3.4 FULL 7z

Lambda Wars 2.3.4 FULL 7z

1 year ago Full Version 1 comment

Install Instructions: 1. Extract contents into your sourcemods folder (default location: C:\Program Files (x86)\steam\steamapps\sourcemods). 2. Restart...

Post comment Comments  (70 - 80 of 1,975)
Firelord475 Jun 29 2014 says:

Would it be possible to change what kind of headcrab is fired from a headcrab canister launcher?

+3 votes     reply to comment
Guest Jun 29 2014 says:

Will vehicles ever be implemented? For instance, the Combine have their APC's and Hunter Choppers, et cetera, and the Resistance have techincals or old Warsaw Pact equipment? This is just wishful thinking on my part, but it'd be neat to see.

+3 votes     reply to comment
APGamer94 Jun 26 2014 says:

I feel that the Sandbox editor needs some improvement aswell. It is fun to be able to place objects anywhere you want and mess around, but players should also be able to save custom, modified/created maps for use in other gamemodes. This would probably be helpful considering some may want to continue their work after a match. Anyone else agree? :D

+1 vote     reply to comment
Pigbear2 Jun 24 2014 says:

How do you rotate buildings? is this just not implemented or am I stupid?

+2 votes     reply to comment
Sander Creator
Sander Jun 27 2014 replied:

The main reason it's like this is because the Navigation Mesh has square sized navigation areas aligned to the world grid ( Placed buildings would break these areas in a weird way. Unless we replace it, I don't think it's acceptable or worth it to have large rotable buildings.

+1 vote   reply to comment
ceu160193 Jun 25 2014 replied:

You can rotate only defensive buildings, rest of them can not be rotated.

+2 votes     reply to comment
ceu160193 Jun 24 2014 says:

Can Combine have bunkers just as effective as Aid Station? I tried many times - barricades + Regeneration Post is insufficient against rebel horde, while 2 AR2 Rebels in Aid Station can withstand rather big Combine assault (if put there 1 RPG guy, they can even withstand Strider encounter).

It appears that buildings provide higher damage reduction than cover.

+2 votes     reply to comment
The_Psycho Jun 20 2014 says:

I always have performance issues with this game, however I can run Half-Life 2 and Alien Swarm Med-High (****** PC) flawlessly. Oh, and BTW the CPU player always uses the same tactic, it builds lots of barracks then rushes into my base.

+3 votes     reply to comment
Reborn:X Jun 20 2014 replied:

The AI was designed at such, it is very hard to design a dynamic AI that actually surprises the player.

+2 votes     reply to comment
bobbyluuu Jun 20 2014 says:


unable to load surface prop file 'scripts/surfaceproperties_hl2.text' (referenced by manifest file 'scripts/surfaceproperties_manifest.text'

How do I fix this? it keeps popping up and I don't know what to do =( and it keeps closing my game when it happens!

+2 votes     reply to comment
Sander Creator
Sander Jun 20 2014 replied:

Validate Alien Swarm files in Steam.

+3 votes   reply to comment
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Released 2012
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1175 votes submitted.

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Highest Rated (14 agree) 10/10

Very original, very fun, and i see a LOT of great potential for this mod in the long run.

Nov 27 2010 by Heroman117


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Lambda Wars
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