OpenXcom requires a vanilla version of the original UFO: Enemy Unknown / X-COM: UFO Defense (any edition) with the latest patch. It is not compatible with other games in the X-COM series. If you don’t own a copy, you can buy it from one of these retailers.

Do not use modded versions of X-COM, as they may be incompatible with OpenXcom.

Check the Installation documentation for more details.



This section contains content made by fans to beef up your OpenXcom experience. Note that third-parties are not affiliated with OpenXcom, and we are not held responsible for any issues that their websites and/or content may contain.

Data Patch

Since OpenXcom depends on the original game data, it also suffers from bugs present in that data like map glitches and problems. To fix these you need to apply a data patch. However, it is recommended you keep a backup of the vanilla game data, in case you start experiencing issues after applying one of these.

Custom Audio

If you don’t like or have trouble getting the original X-COM audio to work, you can use custom ones, such as PSX music, remixes, etc. See the wiki for more details.

(extract to your data\SOUND folder)


OpenXcom has long been customizable, but 1.0 added support for properly packaged mods. Everything from custom maps, weapons, units and more can be easily downloaded and configured in OpenXcom. For installation and usage instructions, always check the included readme or the wiki documentation.

If you’re interested on making your own mods, check the wiki and forums for more details.


The OpenXcom translations are fan-maintained and update at a completely different pace from the milestone/nightly builds, so it’s impossible for us to keep them in sync. If you need the absolute latest translations, you can grab them here and extract them to your data\Language folder. Note that this includes everything available in Transifex, from the masterfully done to the woefully incomplete.