Fabula Nova Crystallis – Latin for “The new tale of the crystal” - is the term for the new series of Final Fantasy XIII games, which so far include: Final Fantasy XIII, Final Fantasy Versus XIII, and Final Fantasy Agito XIII. Though they are within the same compilation these games are not sequels, instead existing in the same universe as unrelated stories, with the Crystal theme tying them together.

Final Fantasy XIII is an upcoming game developed and published by Square Enix exclusively for the Sony PlayStation 3. First appearing at E3 2006, the game features a futuristic, high-tech world, and a storyline focusing on "those who resist the world".

Alongside Final Fantasy XIII and Final Fantasy Agito XIII, the game Final FAntasy versus XIII is a part of the Fabula Nova Crystallis Final Fantasy XIII compilation. The game focuses on a mysterious protagonist who is the last heir of a dynasty ruling over the only remaining city to control crystals. Under unforeseen circumstances, he makes a stand against marauders seeking to take the crystal as their own.

Final Fantasy Versus XIII; is, according to its developers, a wholly independent story unfolding with different characters and a different visual design. And, although it is set within the same Final Fantasy XIII universe, it is unrelated to any other entry within the compilation.