XCOM, is a science fiction video game franchise featuring an elite international organization tasked with countering alien invasions of Earth. The series began with the strategy video game X-COM: UFO Defense created by Julian Gollop's Mythos Games and MicroProse in 1994. The original lineup by MicroProse included six published and at least two canceled games, as well as two novels. The X-COM series, in particular its original entry, achieved a sizable cult following and has influenced many other video games; including the creation of a number of clones, spiritual successors, and unofficial remakes.

Strategy is a major video game genre that emphasizes thinking and planning over direct instant action in order to achieve victory. Although many types of video games can contain strategic elements, as a genre, strategy games are most commonly defined as those with a primary focus on high-level strategy, logistics and resource management. They are also usually divided into two main sub-categories: turn-based and real-time, but there are also many strategy cross/sub-genres that feature additional elements such as tactics, diplomacy, economics and exploration.