Stellaris was released on May 9, 2016 after being developed by Paradox Development Studios. Within the first day, it was reported that 200,000 games were sold. This was the company's fastest selling game ever. Since then, a wide variety of expansion packs have been created. These have all been named after famous science fiction writers, including Iain Banks, Douglas Adams, Ray Bradbury, Ursula K. Le Guin, Gene Wolfe, Arthur C. Clarke, Isaac Asimov, Robert A. Heinlein, and Mary Shelley. The game can be played by a single player or multiplayer. Platforms for Stellaris include Windows, macOS, Linux, PlayStation 4, and Xbox One. On May 24, 2016, the first patch was released which provided many improvements, along with the ability to play other races. Two years later a 2.0 patch was released in February 2018. Game mechanics were revamped. The 2.1 update was released in May 2018, which improved the base game. Many quality of life features were added with this update. In December of this same year, the 2.2 version was released, which improved how the planets are organized. There are many Stellaris mods that are able to be downloaded from different sources. These include downloading them manually from Paradox or automatically using Paradox Launcher. If you use the Steam version, you can find a mod using the Stream Client application. It may also be done through the User modifications sub-forum. This is manually done, but game registration is needed. There are many mods that can be used in the game. Planets can have a new class created that can be colonized, made into a star, or one that is not able to be inhabited. These planets can have rules that must be met in order for them to spawn. These rules may deal with the thickness of the planet, the size compared to other planets, and how saturated the atmosphere is.