A replacement engine for the original X-COM tactical strategy games.
SetupYour game files requiredOpenXcom engine screenshot reference showing tactical movement preview; not a capture of the WebAssembly build.
Game imagery remains copyright its respective rights holders. Image published at https://openxcom.org/screenshots/.
Source & attribution ↗View image ↗A replacement engine for the original X-COM tactical strategy games. The current website points downloads to OpenXcom Extended, a separate project. This entry preserves the original OpenXcom repository and is classified as source/build.
In the original UFO Defense, defeating an alien squad is only part of your job. You also direct the organization that intercepts UFOs, researches recovered equipment and manufactures better weapons. Ground missions feed that strategic layer: bringing alien technology home creates opportunities that simply surviving a firefight does not.
That connection is the attraction for a player who likes decisions to matter beyond one battle. Spending resources and recovering useful material shape the tools available to your next squad. OpenXcom covers both UFO Defense and its separate sequel, Terror from the Deep; each needs its own original resources.
OpenXcom replaces the engine while reading the original games’ artwork and other resources. The source-build route here uses the original OpenXcom repository. OpenXcom Extended is a separate project, so a feature advertised for Extended should not be assumed to exist in this engine.
Customization is a substantial part of OpenXcom. Standard mods accompany the engine, and additional mods live in the user directory and are enabled through Options → Mods. Begin with an unmodified installation before adding a ruleset: the project specifically warns against using already altered XcomUtil data as the base.
The engine separates original data, configuration and user files. UFO and TFTD resources belong in their corresponding data subdirectories, while the user directory holds saves, screenshots and installed mods. Keeping track of that user directory makes it easier to preserve a campaign when moving or rebuilding the engine.
Windows, macOS and Linux use different default locations, and command-line options can select explicit data, user and configuration folders. The README also explains a common mod-installation problem: an extra directory level inside an archive can hide its rules and terrain from the engine. Check the documented directory layout if an installed mod does not appear.
Unmodified resources from UFO: Enemy Unknown (X-COM: UFO Defense) or X-COM: Terror from the Deep. Modded XcomUtil installations are not suitable base data.
Creator-reported · Project guideBuild the OpenXcom engine using its platform instructions, then copy the UFO or TFTD resource folders into the matching data subdirectory.
Creator-reported · Project guideThe source documents Windows, macOS and Linux builds.
Creator-reported · Project guideThe current website points downloads to OpenXcom Extended, a separate project. This entry preserves the original OpenXcom repository and is classified as source/build.
Creator-reported · Project guideOpenXcom engine screenshot reference showing tactical movement preview; not a capture of the WebAssembly build.
Image credits ↗OpenXcom’s alien-defense campaign with local game files, persistent saves and offline caching.
Jagged Alliance 2 Gold publisher screenshot reference; not a capture of the browser port.
Image credits ↗JA2 Gold’s tactical campaign through Stracciatella, using your own Data folder.
Map excerpt from the Freeciv-web community server’s published 2021 screenshot. It illustrates the project, not a current session or compatibility test.
Image credits ↗Caesar III with modern compatibility and small usability improvements.
OpenRA creator footage still showing its Red Alert ruleset. Other included rulesets have different units and settings.
Image credits ↗Classic Westwood real-time strategy games reimagined in a modern native engine.
