Final Fantasy XV is based on the Fabula Nova Crystallis mythology that revolves around a struggle between divine beings and the l'Cie, servants chosen by these gods and granted magic powers to fulfill a predetermined task. However, the precise impact of these concepts on the story is not known. The game is set in modern times, but the city-like country Lucis which protagonist Noctis hails from is the only technologically advanced location, otherwise surrounded by medieval nations. The reason for this divide is a cold war waged over crystals, the last of which Lucis holds. The other nations used to have their own crystals, but lost them due to ongoing conflicts. They have since focused their efforts on the development of weapons rather than on the progress of their culture, which left them in their regressive state. Just as the cold war ends and a treaty on the peaceful use of crystals is declared, the nation Niflheim unexpectedly invades Lucis, forcing Noctis and his friends to escape. Having waged wars against the countries Solheim, Tenebrae and Accordo, Niflheim's forces conquer the last remaining crystal, but Noctis tries to stop them before they can leave the city.