About Lambda Wars (formerly Half-Life 2: Wars)


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. You also must legally own Half-Life 2: Episode Two. 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

For more questions and information please refer to our community forum.


NL Sandern
Programming, Level Design

US Arietta
Level Design

DE ProgSys
Models, Level Design, Interface

UK Pandango
Level Design

UK Sbeast64

DE Sergeant Toni

US Ennui


  • Dave
  • Sergeant Toni
  • Discrate
  • Fromagon
  • HellSpawn
  • pychnight
  • Hevcrab
  • Omi
  • Warbrand
  • Masked Death
  • Syn
  • Leadcold
  • LpSilent
  • Tank Dempsey
  • Quadtrike
  • Nakashimakun
  • [P]etya
  • Gauss5546


  • JLMCYT - Spanish Translation
  • Kriz - Menu Music
  • Jake - TNT Model
  • Anti Viper - Level Design
  • BiotecVirus - Textures and Trailers
  • Garrador - HUD Design and Textures
  • Jister - Beta 0.5 Building Models
  • Steve - 2007 to ASW Model Conversion
  • Lt_Commander - Textures
  • ChromeAngel - Various building models
  • Nqss[RUS] - Level Design


If you are interested in contributing to Lambda Wars - maps, models, textures, sounds, music, etc - please post on our community forum with examples of previous work.