Prior to the game's opening, the Rise of Morastrum occurs again, and people begin seeking the Child of Destiny to discover their eventual fate.

[5] During their journey, the chosen protagonist learns that the Rise of Morastrum is tied to a realm called the Abyss and its ruling Four Sinistrals, which creates the heralding eclipse to manifest their power through the Child of Destiny.

The chosen protagonist and their party close the Abyss Gates and defeat the Sinistral clones sent through to wreak havoc in the world.

While he wanted to return to the narrative and gameplay style of the original Romancing SaGa, he was unsure how to do it while innovating on the design.

An early suggestion was to make the game a direct sequel to Romancing SaGa, but Kawazu wanted it to be an entirely original work.

[9] Kawazu gathered ideas from the development team, which led to the character-specific mechanics such as Mikhail's war campaign and Thomas's trading mini-game.

They were originally grander than the final versions, with Kawazu intending players to clear the whole game using these character-specific mechanics.

[8] The game was produced by Michio Okamiya, who was chosen by Kawazu after previously working in the company's advertising division.

[10] The scenario was designed to combine the freedom of choice of earlier titles with the overarching narrative, with all the protagonists being part of a shared world and crossing paths during the adventure.

[11] When writing the story, Kawazu decided that the heroic Matriarch should be a woman as traditionally the demonic antagonists of games at the time were male.

Kawazu did not communicate this clearly at the time, so when graphic designer Hiroshi Takai created the opening cinematic, he wrote the Matriarch as a male "Hero King".

[17][18][19] The Super Famicom version of Romancing SaGa 3 went unreleased outside Japan, due to a combination of its potentially off-putting complexity and the amount of text needing translation.

[25] Hardcore Gamer described the games open world as being innovative in 1995, but without a clear sense of where to go or what to do on occasion leading to the aforementioned difficulty.

[28] Nintendo World Report also cited the revamped graphics, comparing them to Final Fantasy VI, but noted that the game did require a lot of “grinding”.

[29] RPGamer noted that players can become so focused on side quests that they must actively steer their characters toward the end of the game.