"X4: Foundations" is the fourth major installment in the history of the X-Universe. Since 2018, Egosoft has released several expansions that enhance the base game elements by introducing new ships, stations, sectors, storylines, factions, and occasionally entirely new gameplay mechanics.

A wealth of Steam achievements serves as both a motivation and a guideline.
The storylines of the DLCs are told through missions that reward players upon completion with unique ships or the unlocking of new sectors. There are also many smaller tasks offered to the player while flying past stations — ranging from trivial to highly difficult. Completing these tasks increases the player's reputation with the respective factions, which grants special privileges.

While exploring deep space, anomalies and lockboxes with valuable content can be discovered. With a bit of luck, unclaimed ships can also be found and taken over. Spaceships can be actively captured, and in the advanced stages of the game, even capital ships can be boarded.
Blueprints for ships and their equipment can be purchased from faction representatives. Blueprints for station modules to build your own industrial complexes can either be bought or hacked.
The in-game encyclopedia serves as a comprehensive reference guide for all aspects of the game and the universe, greatly enriching the overall experience.