The production of The Legend of Legacy began in 2013; multiple industry and genre veterans were joined the development staff, including director Masataka Matsuura, designer Kyoji Koizumi, promotional artist Tomomi Kobayashi, writer Masato Kato, and composer Masashi Hamauzu.

[6] Initium acts as a hub for the party, where they can buy and sell equipment and maps, and talk with non-playable characters to learn story and gameplay information.

The party has access to eight weapon types, which can be freely assigned to each character and impact their statistics and battle abilities; Fists (melee combat) Long and Short swords, Axes, Spears, Staves, Bows and Shields.

Each party member can partner with Elemental spirits aligned to Fire, Air, Water and Shadow once they find special relics during exploration.

[9] Contrary to the majority of role-playing games, character stat increases do not rely on an experience point system, instead depending on usage during battle.

Winning a battle awards the party with items and currency, but also randomized stat increases, raising a character's health or attack power.

[11][12] Each of the seven protagonists are drawn to Avalon for different reasons: Meurs is summoned by the distressed calls of Elementals; Bianca goes on a quest to discover her identity, Liber is in search of the Star Graal as treasure; Eloise searches for the Star Graal to discover the secret of immortality; both Garnet and Owen are sent by the Holy Order to investigate Avalon due to its rumors of living gods and their consequent heretical status; and Filmia resolves to rebuild his kingdom.

The ancient native kingdom was once prosperous through the efforts of Elementalists, sorcerers who created and communed with Elementals, harnessing their power and consequently growing overly dependent upon them.

Emerging victorious, Amelius created an artifact called the Star Graal, granting immortality to himself and his followers including General Cherubim, the only military figurehead to betray Avalon's former ruler.

The destruction of the Star Graal leads to the deaths of Amelius's followers and the return of starlight, allowing nighttime navigation at sea and opening the way for Initium to become a major port.

Each character has their own ending: Meurs continues his wanderings satisfied that the Elementals have been freed; Bianca decides to forge her own life free from her origins; Liber briefly settles down before setting out on another adventure; Garment decides to leave the Church to explore the wider world; Eloise—revealed to be actually called Lydia, sister to the real Eloise—decides to return to her sister; Filmia establishes his kingdom on Avalon and is hailed as a new god; and Owen is hired by the Church to hunt Filmia.

[13] The Legend of Legacy was principally developed by Cattle Call, with game design by Grezzo and general supervision by Atlus.

Ryoji Shimogama, whose previous credits included the Resident Evil series and Parasite Eve 2, worked on monster designs with Kojima.

[11][16][17][18][19] The concept of The Legend of Legacy was being created by Matsuura before he joined FuRyu, and became a reaction to the proliferation of casual mobile games in Japan.

He was intent on creating an RPG reminiscent of the genre's golden age, using the RPGs of Square such as Final Fantasy and SaGa as his inspiration.

[20] While FuRyu's other major titles in development at the time—Exstetra and Lost Dimension—were aimed at younger audiences, Matsuura was intended for those who had played golden age RPGs.

[15][16] The continent of Avalon was built up from the earliest piece of concept art, which encapsulated the island's ancient civilization, current condition and the game's artistic direction.

[21] The "Cartograph" mapping system was created by Koizumi to make exploring entertaining, but Matsuura added explanatory elements as the original version was proving difficult to understand.

[11] Atlus USA chose the title for localization due to their positive working relationship with FuRyu, having already picked up Lost Dimension for release.

After it received positive critical reception in Japan, Atlus decided to work with FuRyu to release The Legend of Legacy overseas.

[22] A demo was released for digital download on September 22, featuring Eloise, Owen and Filma exploring the game's two opening dungeons.

"[41] Following the release of The Legend of Legacy, Matsuura wanted to create a story-driven role-playing game similar to those from the genre's golden age.