In the 2016 mainline title Final Fantasy XV, Prompto accompanies Noctis on his journey by road to meet and marry a noblewoman from another nation, and fights alongside him as they oppose the Niflheim empire.

A major element of Prompto's character is his humble origins when compared to the aristocratic families of Gladiolus and Ignis, the other members of Noctis' retinue, with his less cultured mannerisms being an obvious embodiment of that.

Prompto was originally created by Tetsuya Nomura as a main cast member of Final Fantasy Versus XIII, a spin-off title meant to be part of the Fabula Nova Crystallis sub-series.

[9] Daymond noted that localization team and the voice actor decided to stop using the original Japanese audio as a reference early in the recording process outside of some limited applications such as technical matters.

Late in the game's narrative, Prompto is knocked off a train that is en route to Gralia, the capital city of the Niflheim empire, separating him from the group for a time.

He is later discovered and rescued by his friends within an installation facility in Gralia, where he reveals that he is in fact the result of Niflheim's cloning experimentations to power its robotic army of magically infused Magitek infantry.

Alongside the mercenary Aranea Highwind, a former agent of Niflheim whom he befriends, Prompto confronts and defeats Verstael, who had transferred his consciousness into a gigantic war machine.

After receiving a letter of appreciation from Lunafreya, Prompto decides to improve his situation by adopting an upbeat outlook towards life, and build his self-esteem by losing weight and becoming a more confident person in the process.

In early 2016, action figures of Prompto alongside Noctis, Gladiolus and Ignis were produced by Play Arts Kai and distributed for sale by Square Enix on its online store to promote the then-upcoming release of Final Fantasy XV.

[17] Shortly after the release of the Final Fantasy XV: Episode Duscae demo in March 2015, Tabata and his team discovered that Prompto came last in a popularity survey, falling behind several minor characters featured alongside the main cast, and was generally disliked by series fans.

[18] This motivated the development team to put more effort into redesigning Prompto's appearance and redefining his in-game role, as they wanted all four members of the group to be equally popular or likeable.

Ethan Gach from Kotaku observed that he stood out among the voiced characters of the Final Fantasy series, as few have had a fleshed out backstory or has been as charming with the sense of fun they impart as Prompto.

[24] Andrew Webster from The Verge said Prompto's photos are a critical narrative tool, which help players tell their own stories while creating a deeper connection with the game's cast.

Jason Schreier and Ash Parrish, who have both written for Kotaku, opined that individuals like Prompto who hide their insecurity and emotional fragility beneath an outward veneer of cheerfulness and pluckiness are very common in real life friend groups, which reinforces the character's relatability.

[32][33][34] Parrish was surprised by how closely she identified with a character whose physical appearance differs greatly from her, as on an emotional level she claimed to have experienced the same feelings of anxiety and self-loathing as Prompto when it comes to her social interactions.

A criticism she offered was that the side story of Prompto's discovery of his true origin was entirely absent in the base game, which she argued undercuts the narrative impact of the disclosure of his identity following his reunion with his friends.