Fate/Extella is being developed by Marvelous, and is written by Kinoko Nasu and Hikaru Sakurai, with character designs by Aruko Wada. When the game was announced in March 2016, development was 60% finished. Development began after the previous Fate game, Fate/Extra CCC, was finished. It is written as an independent story, with Takashi Takeuchi describing it as not being a counter to Fate/stay night or a sequel to Extra; according to Nasu, the story still “inherits the blood of Extra”.
Marvelous has developed alternative costumes for characters as downloadable content: one such costume, for Gilgamesh, had to be redesigned for “various reasons”. While Marvelous did not elaborate, some journalists speculated that it was due to its resemblance to Nazi officer uniforms.
In Japan, multiple editions of the game will be available: the “Velber Box” includes one copy of the game for the PlayStation 4 and one for the PlayStation Vita, a box with art by Wada, an oppai (“breast”) mousepad depicting a Saber servant, a book with development information and a glossary, a download code for alternative costumes for the servants Nero and Gilgamesh; the “Regalia Box” includes one copy of the game for either platform, the box, the book, and a download code for one of the costumes included in the Velber Box. All Japanese copies of the game also come with a download code for two additional costumes, for Nero and Artoria Pendragon. Copies bought at Loppi or HMV also include one more costume, for a male character. Meanwhile, Japanese digital purchases include a “Dragon Magician Girl” costume for Elizabeth Bathory. Additional downloadable costumes will be published after the game’s release, including a set of nine swimsuits, one set of seven women’s clothes, one set of nine men’s clothes, and one of three Fate/stay night costumes.