Concept and creation
The concept and setting of Final Fantasy XV, initially a spin-off titled Final Fantasy Versus XIII (ファイナルファンタジーヴェルサスXIII Fainaru Fantajī Verusasu Sātīn), was created by original director Tetsuya Nomura. Initially in development for PlayStation 3, Versus XIII was shifted to the eighth generation consoles PlayStation 4 and Xbox One. During this transition, Final Fantasy Type-0 director Hajime Tabata became co-director; later in development, he assumed full directorial duties from Nomura. The development period ultimately lasted about ten years, although Tabata now refers to Versus XIII and XV as different games.
The game was originally part of Fabula Nova Crystallis Final Fantasy, a collection of games united by a common mythology and shared themes. When it was renamed, XV "disconnected" from Fabula Nova Crystallis; although the mythos was retained, its role in the story was reduced and its unique terminology was removed to aid with marketing and provide Final Fantasy XV with an individual identity. A surviving theme from the mythos was the struggles of humans chosen by a divine crystal. The central concept behind the world of XV is "a fantasy based on reality": the setting is based on the real world and the fantasy elements grew out of familiar settings. Realizing this aspect of the game was quite difficult for Nomura before the game's move onto eighth-generation hardware. While the story was similar to other entries, he wanted to create more realistic characters. His ambition was to make XV "about man in the real world", including less fantasy elements. He also described Final Fantasy XV as the darkest entry in the series, acknowledging that this atmosphere might narrow its target audience while feeling that the time was right for such characters. Nomura wanted to depict a story centered on a group of men traveling the world, much like that of a road movie. This approach was inspired by experiences from his youth, in which he often witnessed single-gender groups taking extended trips. Nomura also did not want the protagonists to be drawn together by a grand destiny, instead being natural friends confronted with bizarre and dangerous situations. To help convey the road movie theme, the team created towns featuring both strange and familiar elements, taking inspiration from the opening scenes of Back to the Future Part II.
The initial story themes were "misery" and "bonds", with all characters representing these themes through their actions and circumstances. It was intended to be a painful story that emphasized the power of friendship. The theme of bonds was represented in Final Fantasy XV by the relationships between Noctis and his comrades, as well as Noctis and his father, Regis. A key narrative element was Noctis' personal journey from prince to king. The original script was written by Kazushige Nojima, who described his story for Versus XIII as "Myth vs. Reality". When Versus XIII became FInal Fantasy XV, multiple aspects were changed. A scene that was removed was the original opening, in which Noctis met another character at a treaty-signing party, then had to escape Lucis when the forces of Niflheim attacked; those scenes were changed to have the group being away at the time of the invasion. However, other characters revealed during earlier trailers were retained and would have important roles in the story. When consulted over how his original draft could be reworked, Nojima said that he would be content as long as the overall concept remained faithful to the original. This gave the team the confidence to rework and realize the original story within XV. This rewriting was primarily done by Saori Itamuro, who was credited as "Lead Scenario Designer". The story takes place over a ten-year period, and the characters' appearances were altered as they aged: this bucked the trend of many similar JRPGs, with the team wanting to properly represent the characters growing through their journey. The game's opening depicts a scene late in the game; this approach was inspired by Crisis Core: Final Fantasy VII, which featured a conclusion linked to the original Final Fantasy VII. In both cases, the developers wanted players to experience a sequence of events leading up to a known conclusion. The ending was left deliberately ambiguous so that players could develop their own interpretations. For both Versus XIII and XV, game staff stated that it would likely be the saddest Final Fantasy story to date. Alongside the serious plot, several elements of light comedy were added as a counterbalance. A large amount of dialogue was conveyed using in-game conversations instead of cutscenes. Nomura also wanted the dialogue to sound "natural and not game-like or lofty".
In contrast to many previous Final Fantasy titles, the playable cast of XV is all male. This concept was chosen by Nomura from the outset, and agreed upon by Tabata despite some later reservations on his part. Women still have significant roles in the story, and Tabata noted in an interview that it is "not healthy to have a bias in genders". The game's main cast was designed by Nomura. The clothing for characters was designed by Hiromu Takahara, lead designer for Japanese fashion house Roen. Takahara's involvement principally came due to the detail needed for the costumes, which were inspired by western fashion: designing them himself would have been time-consuming for Nomura to do along with his other duties, which included designing characters for Final Fantasy XIII. He also wanted to continue to express the game's realism through the character outfits. The design trait for the main characters was "jet-black", while all the character clothing in the game utilized Roen's distinctive asymmetrical styling. Roen's designs were kept in the game when it became XV, as the team felt it would be wrong to remove them. The changeover from Versus XIII to XV resulted in the redesign of characters such as Regis, and the replacement of the previous main heroine Stella with the similarly-named Lunafreya. A result of the shift onto new hardware was that the art style moved away from the "stylized" look required by earlier hardware limitations. To help maximize the realism of the characters, their hair was first created by a hairstylist using a mannequin's wig, then rendered into the game using the technology of the Luminous Studio engine. The same technique was used for Agni's Philosophy, the engine's demo at E3 2012.
The characters of Ardyn, Gentiana, Iris, Aranea, Umbra, Cindy, Cid, and Verstael were all designed by Roberto Ferrari, who had previously done work on Type-0 and was involved with the project from its earlier development as Versus XIII. These designs were completed by 2010, when the project was still known as Versus XIII. Ferrari was brought on board the project in 2010 after an unidentified female designer resigned from the project as her art was repeatedly rejected by the developers. The change and subsequent alterations to the game's content meant that many of Ferrari's character designs went unused, something he was openly frustrated about as he considered these unseen characters more visually striking than his surviving designs. Many of his surviving character designs were altered during later development, including those for Gentiana and Umbra. Ardyn and Aranea remained mostly unchanged. Another contributing artist was Yusaku Nakaaki, who helped design the character Cindy.
Final Japanese voice casting for the game began in 2010. The English localization of XV was led by Dan Inoue. One of the aspects of the localization was using different accents to show the characters originating from different regions of the world: a cited example was Ignis, who spoke with a British accent while the other main characters spoke with an American accent. One of the early issues—which drew public attention with the release of Episode Duscae—was Noctis's voice in the English dub; it was pitched rather low, making the character seem older and less energetic than his Japanese counterpart. This was explained as being due to tight scheduling removing the opportunity for Tabata to catch the issue and re-record before it was time for release. After Episode Duscae, the voice work was redone to better convey Noctis's personality. Different issues raised later included Ignis's localized lines, which changed aspects of the character interaction, and the alteration of Cindy's name from the original "Cidney". In an interview with Famitsu during Gamescom, Tabata revealed that the main reason for the delays in XV's release were related to the game's localization and debugging, as the team wanted to bring the game out in the west close to its Japanese release. In addition to being released with French and German dubs and text translation for those respective regions, it was also localized for Latin America with Latin American Spanish and Brazilian Portuguese text: this was the first time a Final Fantasy title was localized into these languages.