It was released worldwide for Windows, macOS, and Linux on May 9, 2016,[2] and for PlayStation 4 and Xbox One as Stellaris: Console Edition on February 26, 2019.

[4] Early gameplay consists of exploring and colonizing increasing swaths of space, while mid-game activities may include engaging with warfare and/or diplomacy with other empires, but can also be filled with a vast amount of micro-management.

Paradox hoped that this feature would address a common late-game problem in 4X style games; whereby one faction is so powerful that their eventual victory is inevitable, resulting in frustrating gameplay.

[8] The game uses the same Clausewitz Engine that the studio has used since Europa Universalis III in 2007[9] albeit with some modifications, such as the usage of physically based rendering (PBR).

[11] Director Henrik Fahraeus describes his influences as "one third Star Control 2, one third Master of Orion 2 and one third Europa Universalis IV", to "create a strategy game with particular focus on exploration and expansion".

[12] The team also referenced Star Control II with several character concepts and personalities, including alien races who resemble birds, mushrooms, and gas clouds.

After launch, the developers confirmed that there would be a number of expansion packs, as well as free updates to address bugs and introduce new gameplay features.

[14] The updates were named after famous science fiction writers, including Arthur C. Clarke, Isaac Asimov, Robert A. Heinlein, Iain Banks, Douglas Adams, Ray Bradbury, Karel Čapek, Pierre Boulle, C. J. Cherryh, Larry Niven, Ursula K. Le Guin, Gene Wolfe, Tanith Lee, and Mary Shelley, until 2022, when they began to take the names of constellations starting with 3.3, "Libra".

The first major patch arrived on May 24, shortly after the game's release, featuring numerous improvements to the AI, as well as an additional playable race.

[15] The 2.0 patch (Cherryh), released in February 2018, revamps a significant amount of game mechanics, even for players who have not purchased the corresponding "Apocalypse" DLC.

The 2.1 (Niven) update, released alongside the "Distant Stars" DLC in May, revamped the base game play loop and added more quality-of-life features.

In a preview of the game at Rock, Paper, Shotgun, Adam Smith wrote that Stellaris "could be Paradox's finest hour, and a landmark in the development of both 4X and grand strategy design".

][not specific enough to verify] The more mixed reviews also noted that the mid-game could be less satisfying, thanks to an overly simple diplomatic system and a somewhat passive AI.[48][who?