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Lambda Wars
Platforms: PC
Languages: English
Dec 1, 2013 @ 9:59am
Dec 8, 2014 @ 7:28am

View Lambda Wars in the store

Store page
Recent Announcements View All (7)
Lambda Wars Beta 2.3.6 Released!
Recruiting a Gameplay UI Designer!
We're still looking for a gameplay UI designer to help us rebuild the interface (menus/lobby first and eventually the ingame interface) in HTML5 via Chromium Embedded Framework. If you're a visual designer adept with CSS and JS and have a knack for UI/UX get in touch via our recruitment forum[].

Lambda Wars 2.3.6 Changelog
Improvements and Balance:
  • Reduced Strider's Dark energy cannon damage radius from 200 to 100
  • Reduced Strider's Dark energy cannon cooldown from 30 to 20 seconds
  • Reduced black and regular headcrabs HP to 80
  • Reduced fast headcrabs HP to 60
  • Unit selection interface: control + left click unit type in hud unit selection will filter selection on that type, while control + right will do the inverse.
  • Add combine victory and defeat effects
  • UPDATED: hlw_base4 (flora)
  • UPDATED: hlw_meltdown (flora, various)
  • UPDATED: hlw_slums (flora)
  • UPDATED: hlw_synth (various)
  • UPDATED: hlw_village (flora, various)
  • UPDATED: hlw_waste (flora, various)
  • UPDATED: or_base4 (flora)
  • UPDATED: or_hill (flora)
  • UPDATED: or_washedaway (flora)
CPU Player:
  • Rebel CPU Player now collects scrap
  • Improve cleanup of stuck enemies
  • Headcrab cannisters are no longer launched between waves
  • Scaled down bounding box of Headcrab Poison boss to prevent navigation issues on or_trapped
  • Potentially broken buildings when the client requested a full game update due packet loss
  • Combine Elite AR2 alt fire ability firing at wrong target due faulty aim code
  • CPU player placing too many barracks, while not producing any units
  • CPU player is now always ready in overrun
  • Incorrect unit navigation when jumping off cliffs/edges (e.g. getting stuck)
  • Headcrabs flying up to an unreachable location after being spawned from a killed zombie (in particular or_base4)
  • Overrun game mode endless wave type not working
  • Overrun game mode waves not progressing
  • Strider's Dark energy cannon ability not taking resources
  • Fix fog of war incorrectly revealed around control points in some cases due mismatch between server and client parameters
  • Tooltips of units and abilities not disappearing on machines with a low framerate
  • Upgrade energy fields of medic being shared with saboteur and scout, due which they can stay invisible forever
  • Fortification of control point not removed after becoming neutral due a player being defeated
  • When a zombie dies "chopped", it would potentially not be removed and become invisible and not solid
  • Add name and description for "Ungarrison All" Ability
  • Updated Python from 2.7.6 to Python 3.4.1
  • Updated spanish translation, thanks to JLMCYT

Lambda Wars Beta 2.3.5 Released!
  • Control point fortification;
  • Maps now look and play much more lifelike due to interactive flora;
  • We're also glad to announce that Lambda Wars no longer require to own Half-Life 2: Episode Two. A free installation of Alien Swarm is now enough to play the mod!

And yes, we're advancing to Steam and need reinforcements to reach this milestone:
- Web-based Game UI Designer URGENT (
- Announcer/Voice actor (for lines such as "Building under attack" or "Need more requisition")

Get the latest full version or patch here, bug reports and feature suggestions are welcome at our
community forums[]!

Changelog for 2.3.5
Improvements and Balance:[/list]
  • Control Points can now be fortified, preventing capturing until fortification is destroyed and increases income
  • Added Rebel Radio Tower detecting cloaked enemies in a radius of 500 and performing
    Scan ability (moved from HQ)
  • Limited number of engineers which can salvage scrap at the same time
  • Raised population limit from 75 to 100
  • Added one additional Combine Population upgrade and updated existing population upgrades
  • Replaced Rebel Engineer smg1 weapon by pistol
  • Replaced Rebel Veteran weapons by Crossbow
  • Increased build time Barracks/Garrison to 80 seconds
  • Increased cooldown time of manhack deploy ability from 20 to 120 seconds
  • Turrets, barricades and sub-component buildings no longer count as valid main buildings in Annihilation mode for victory conditions
  • Reduce costs headcrab canister launcher builder from 40 req + 60 pow to 30 req and 40 pow.
  • Reduce costs of launching headcrab canisters from 50 req + 50 pow to 30 req and 60 pow
  • Reduce cooldown launching headcrab canisters from 30 to 8 seconds
  • Replaced sprite based detail props by flora models
  • Updated unit glow effect (less obtrusive)
  • Units now get a green tint when detected while cloaked. Additionally the team color glow is enabled again from the enemies point of view and can be targeted by the enemy player.
CPU Player:
  • Various adjustments in resource management
  • Added Hard difficulty
  • NEW: hlw_synth (8-player FFA)
  • UPDATED: hlw_waste (complete revamp & added flora)
  • UPDATED: sp_radio_tower (flora)
  • UPDATED: sp_valley (flora)
  • UPDATED: hlw_forest (flora)
  • UPDATED: hlw_washedaway (flora)
  • UPDATED: hlw_mine (flora)
  • UPDATED: hlw_aurora
  • REMOVED: hlw_battlemounds
Unit AI & Navigation:
  • Right clicking a barricade now makes selected units go into cover around the barricade
  • Improvements in navigation around barricades/mountable turrets
  • Now defaults to 10 waves to win the game
  • Increased preparing time between waves
  • Added button to indicate the player is ready for the next wave (skipping remaining prepare time)
  • Wave progress bar displaying the number of enemies left to kill
  • Player now starts with 25 population. Tier 2 increases it with 25 and tier 3 increases it with 50.
  • Tier 2 upgrade now costs 12 kills and tier 3 upgrade costs 15 kills (both were 20)
  • During Leap attacks of Antlion and Headcrabs, they no longer collide with units of their same team
  • Made various costs changes for Overrun. Hunter and Vortigaunt now cost 5 kills instead of 8 kills. AR2 soldier now costs 2 kills.
  • Added two bosses for Zombies wave mode. They start appearing at wave 7. One is a larger version of the poison zombie, which throws more black headcrabs at once. The other one is a giant black headcrab, which spits acid.
  • Boss type like units must be killed to progress to the next wave
  • Enemy fire/tracer/sound effects not visible/played when they shoot at your units from a position hidden in the fog of war
  • Soldiers holding weapon models incorrectly
  • Annihilation game mode does not directly ends after destroying the last building (waits until the destruction animation finished playing)
  • Unable to target Fuel or Explosive barrels using Attack Move ability
  • Hunter blood effects not stopping after being healed
  • Engineers not auto-casting "construct" ability after turning on autocast while being near a building needing construction or repairing.
  • Unit not shooting enemies while being in cover and uncloaking
  • Units going into cover at incorrect places when returning to idle position.
  • Weapons of cloaked units were visually not cloaked
  • Headcrab Cannister launcher still spawning headcrabs for a moment after being destroyed
  • Single moving units sometimes getting stuck along a wall
  • CPU difficulty not shown correctly to new players joining the game lobby
  • Improved behavior of pausing the game in single player (broken because of an Alien Swarm engine bug)
  • No longer required to own Half-Life 2: Episode Two. A free installation of Alien Swarm is now enough to play the mod!
  • Added partial Spanish translations
  • User Steam avatar is displayed in the to top left corner of main menu.

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.

Previously known as Half-Life 2: Wars, Lambda Wars has been in steady development with a long history of acclaimed public alpha and beta releases since late 2007 and only requires Alien Swarm (free) installed on Steam to play.
Click here[] to learn more and get started playing Lambda Wars right now.

  • 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
  • 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
  • Custom navigation code and deep Python integration - all unit and AI code is scripted in Python

Current Release: Beta 2.3
Download and play at

System requirements are the same as Alien Swarm, with the exception that GPU with Shader Model 3.0 support is required.

OS: Windows® 7 / Vista / Vista64 / XP
Processor: Pentium 4 3.0GHz
Memory: 1 GB for XP / 2GB for Vista
Graphics: DirectX 9 compatible video card with 128 MB, Shader model 3.0. NVidia 7600, ATI X1600 or better
Hard Drive: At least 2.5 GB of free space
Sound: DirectX 9.0c compatible sound card

OS: Windows® 7 / Vista / Vista64 / XP
Processor: Intel core 2 duo 2.4GHz
Memory: 1 GB for XP / 2GB for Vista
Graphics: DirectX 9 compatible video card with Shader model 3.0. NVidia 7600, ATI X1600 or better
Hard Drive: At least 2.5 GB of free space
Sound: DirectX 9.0c compatible sound card
Popular Discussions View All (54)
Dec 17, 2014 @ 12:36am
New Unit Ideas for rebels
Lord Toadster
Jan 26 @ 7:25am
New Unit Ideas for combie
Lord Toadster
Dec 6, 2014 @ 9:27pm
Add a vort faction.
< >
zombie May 14 @ 3:09am 
good game 10/10
Headshop-bitch! Apr 25 @ 11:05am 
Кароч та же дота
OxYDarkLight Mar 3 @ 4:07am 
very good game
Shas'ui Demotana Feb 27 @ 1:33pm 
You guys are legendary.
RESISTλNCE REBEL Feb 26 @ 2:14pm 
i never thought i would see the day
Василиск Jan 26 @ 7:09am 
Cool game!)
DudeBro Dec 9, 2014 @ 12:46pm 
Anyone know how to get this game to download? Whenever it reaches around 90% the download stops and displays the text:
An error occurred while updating Lambda Wars Beta (disk read error)
Ultimate Mayhem Dec 9, 2014 @ 9:38am 
FINALY! ITS Released! :D
Error54 Dec 7, 2014 @ 12:30am 
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>IG< Cid Del Cephalopod (TPE) Dec 6, 2014 @ 10:24am 
is there gonna be full LAN support, and any plans to make it a standalone game