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Free & open-source reimplementation of Imperium Galactica. Download the Installer below the file list!


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Current game version: BETA Latest GitHub Release Version

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Download options


Please download the game files via these methods to preserve the free GitHub bandwidth granted to free projects.

Download size

  • 1.21 GB (1.309.131.999 bytes)


  • SHA1 67b3e8f81d2b25b68fc351ecd5ad7b737335b218 *
  • SHA256 e2154b8d5bbcceb8d2f250ef6bc4bf309d77ddd069dc6d4d2a23a5aa921746b8 *

Last resort

If the preferred methods don't work for some reason, you can download just the launcher which will download the rest of the files from this project page.


Open Imperium Galactica (Open-IG) is an open source JavaTM reimplementation of the Digital Reality game Imperium Galactica, a popular, 4X (eXplore, eXpand, eXploit, and eXterminate) real-time space strategy game developed around 1996 in Hungary.

The project contains all necessary files (with the permission from the copyright owner Digital Reality) to run the game standalone, there is no need for the original Imperium Galactica files.

System requirements

Minimum Recommended
Java 11 x86 or newer1 Java 11 x64 or newer
Any operating system with graphical user interface 64 bit operating system with graphical user interface
A mouse with scroll wheel A mouse with scroll wheel
832 MB RAM 3 GB available RAM
1.4 GB disk space 2 GB disk space
1.5 GHz Dual Core CPU 2 GHz Quad Core CPU

1Technically, Java 7 is enough but running the launcher with it may cause trouble connecting to GitHub due to outdated TLS support in Java 7.

I recommend picking up the latest version from site.

Supported languages:

  • English
  • Hungarian
  • German
  • Russian
  • French
  • Spanish (graphics and text only)

Notable Enhancements over the original game


  • Resizable game window beyond 640x480
  • Scalable user interface
  • Alternative font rendering
  • Rain and snow effects
  • Higher resolution ingame videos

User interface

  • User profiles
  • Switch between languages
  • Achievements screen
  • Statistics screen
  • Black Market screen
  • Quick research panel
  • Quick production panel
  • Tooltips
  • Video subtitles
  • Mouse-based map dragging
  • Add/remove 10s/100s of items
  • Mission objectives display
  • Dropdown menu listing the screens
  • Planet problems icons
  • Planet overview panel
  • Planet listing with more status information
  • Zoom in/out on planets
  • Right and middle mouse usage
  • Watch unlocked ingame videos/cutscenes
  • Audio volume controls & mute settings
  • More mouse, visual and game settings


  • All game speeds avaliable from the start
  • All music available from the start
  • Spacewar and groundwar speed controls
  • Additional game speed option
  • Moddable campaigns
  • Customizable skirmish games
  • Empire & AI Traits
  • Pave over surface features
  • Transfer colonists
  • Abandon colonies
  • Non-cheating AI
  • AI managed planets
  • Request colonization
  • Spacewar and groundwar unit grouping
  • Auto- and quicksaves
  • Buy ships and vehicles from a Black Market


Some systems and configurations may not run the game properly. Please refer to the Troubleshooting guide for workarounds and resolutions.




Thanks to Bajor "Danyetz" Dániel for the spying related work for IG2 DLC, weather effects and some other new developments.

Big thanks to Grigoriev Kirill for the Russian translation.

Thanks goes to Silvern Tiger for testing and translation.

Big thanks goes to Norbert "Silver83" Pellny, who took the enormous job and cleaned the game background images, helped with the german version and tested the game tirelessly.

I'd like to thank Torma "Joe" József for his intensive testing and help with the sound, graphics, AI, concepts and many more things.

I'd like to thank TCH from DOSGames forum for helping me discover the animation file format. He gave the idea to check for two compression steps instead of only one.

I'd like to thank my colleague Galaxy for creating the new Open-IG splash screen and helping me with the data model behind Open-IG.

I'd like to thank Harrach Gergely for the Credits data, ship firepowers, subtitles and other stuff.

I'd like to thank Góz Tamás from for identifying some of the voice actors.