X-COM: UFO Defense — Classic XCOM on Windows
X-COM: UFO Defense is an early game in the X-COM series built around global defense, UFO interception, base building, research and tactical ground missions.
UFO interception and ground combat
Choose where to build and maintain bases, intercept UFOs, and decide which engagements are worth the operational risk. Ground battles are tense because visibility, movement and alien reactions can punish aggressive scouting.
Research and strategic management
Recovered alien technology is central to progression. Research projects, manufacturing and government funding influence which tactical options you can afford.
Classic game vs modern XCOM
UFO Defense has an older interface and different rules from the reboot. Do not assume the same cover, action economy or progression systems found in XCOM 2.
Playing on a modern Windows PC
Check the compatibility guidance for the particular distribution you own. Historical Windows requirements do not guarantee the original executable runs natively on a recent Windows machine; a supplied compatibility layer may be involved.
Frequently asked question
Are X-COM: UFO Defense and UFO: Enemy Unknown related?
They are regional names for the classic X-COM title, separate from the later reboot XCOM: Enemy Unknown.
Sources and related Windows guides
All Windows guides · Best XCOM games · XCOM 2 · Chimera Squad
Editorial note: This article summarizes published game information and does not claim hands-on testing of every Windows configuration. Updated October 21, 2026.