The development of Final Fantasy XV, a Japanese action role-playing video game, began in 2006 shortly before its announcement at that year's Electronic Entertainment Expo. Square Enix handled primary development on XV, and the game was released worldwide in November 2016; the total development time covered approximately ten years. The game was originally announced as Final Fantasy Versus XIII, a PlayStation 3-exclusive spin-off title. It was part of Fabula Nova Crystallis Final Fantasy, a subseries of games linked by a common mythos: while retaining thematic links, specific references were removed to aid with marketing. Additional media was created to portray the world of XV without using sequels; dubbed the "Final Fantasy XV Universe", it included a feature film, an original net animation, a virtual reality simulation game, multiple mobile projects including an abridged version of the game, ports to Windows and Stadia, and a novel The Dawn of the Future depicting an alternate finale.
The game was originally directed by Tetsuya Nomura, who also created the story concept and main character designs. Nomura wanted to create a darker Final Fantasy title unsuitable for the main series. The initial development went slowly, and by 2007 the scale of the project generated discussions about rebranding the game as the next main entry in the series. Production on Versus XIII ended in 2012, when it was rebranded as Final Fantasy XV and transferred over to the PlayStation 4 and Xbox One. The PlayStation 3 version, which was originally built using the company's proprietary Crystal Tools game engine, was abandoned due to concerns about the platform's shortening life cycle. Its engine was changed to the Luminous Engine, custom-built by Square Enix for eighth-generation gaming hardware.
After its change of platforms, the production team headed by Hajime Tabata, whose previous work included Crisis Core: Final Fantasy VII and Final Fantasy Type-0, was brought on board to aid production. Tabata became co-director, and was eventually promoted to sole director after Nomura was transferred to work on other projects within the company. After the transition to eighth-generation hardware, multiple changes were made so that it better suited the new consoles and its new status as a mainline game: these included radical staff reshuffles, and the reevaluation of the game's content. The latter part resulted in some scenes and characters from Versus XIII being cut. Later in production, multiple other studios were brought in to help with various aspects of the game.
Since its original announcement, release of information became sporadic, leading to video game journalists labeling it as vaporware and eventually to rumors of its cancellation. After its public rebranding in 2013, the silence continued until its appearance at the 2014 Tokyo Game Show, at which point development and progress information was released on a regular basis. A demo for the game, Final Fantasy XV: Episode Duscae, was released in March 2015 with first print copies of Final Fantasy Type-0 HD. Promotion for the title was effectively restarted at the 2015 Gamescom. Its release was delayed due to polishing work and the wish for a simultaneous worldwide release, something no other mainline Final Fantasy title had managed to accomplish. Cosmetic, gameplay and story-based downloadable content (DLC) were developed between 2016 and 2019 to fix issues raised by players and expand upon the base game.