Radiant Historia takes place on the continent of Vaingueur, which is divided into five countries. The protagonist Stocke hails from the nation of Alistel, which is currently at war with the country of Granorg. Alistel becomes stricken with a crisis when the country starts turning into desert, and people start turning into sand. The leaders of Alistel insist that this is being caused by Granorg, which intensifies the war effort.
At the beginning of the story, Stocke is given a book called the White Chronicle, and is paired with two soldiers, Raynie and Marco. Their mission is to find secret agent who has been trapped in Granorg territory. They succeed in finding the agent, but then become surrounded by enemy forces and the agent is killed. After succumbing to a deep wound, Stocke wakes up in an another dimension called Historia which seems to twist time and space. Stocke gains the ability to travel through time and space with Historia as the relay point, which he will use to create the proper history for the continent.
- Stocke: A 19-year-old agent of Alistel's intelligence agency, and the main protagonist. He tends to keep quiet, but in truth he cares strongly about his mission and his subordinates.
- Raynie: A 17-year-old mercenary assigned as Stocke's subordinate. She is very honest and blunt, and has a short-temper.
- Marco: A 17-year-old agent assigned as Stocke's subordinate along with his friend Raynie. Unlike Raynie, he is more calm and thinks carefully before acting.
- Heiss: Head of the intelligence agency Stocke serves. He is known for being a very calm and calculating individual.
- Rosch: A captain in Alistel's military. Has a friendship with Stocke. Due to an injury, he lost his left arm and instead has a mechanical replacement.
- Sonja: Oversees the medical division and a researcher. Friends with Stocke and Rosch.
- Lt. General Raul: A Lt. General who stays behind to work on tactics and strategy. Friendly to Rosch and Stocke.
- General Hugo: General who is the mouthpiece of Noah, who is the prophet of the religion in Alistel. He is known for being very animated.
- Aht: A 9-year-old Satyros, and part of a traveling entertainment group. Little to her knowledge she is a shaman. She is enthralled with Stocke.
- Queen Protea: The ruler of Granorg. She is commonly regarded as a tyrant as she ignores the needs of her people and only cares for the luxuries of her position.
- Eruca: Stepdaughter of Protea. Unlike her stepmother, Eruca is concerned for her people and is well-liked by the citizens.
- Gafka: Powerful and skilled martial-artist from the beastkind city of Forgia. Is banished by his own wish from his homeland to Celestia, but will not say why.
- Teo and Lippti: Twin guides of Historia. They claim that the world is headed to destruction and ask Stocke to help stop it. They advise him in his quest and allow him to use Historia to travel from one point of time to another.
Stocke gains the ability to travel back and forth between the past and present. Changing the past will sometimes dramatically affect the future. As you progress through the game, you will activate time nodes that you will be able to revisit later. These nodes usually put you at key decision points. At these points, the timeline will split, and by traveling back to the node, you will be able to make a different decision to experience the other timeline. Some of these timelines will only lead you to dead ends, after which you will be put back to a prior node. The ultimate goal is to discover the correct timeline, however you will still need to explore the other timelines to complete the game. At several points, even after making the right choice, you will find your path blocked due to circumstances beyond your control. In these situations, you can usually solve the problem by exploring another timeline and changing the outcome of certain events. This will change the circumstances in the original timeline, and allow you to continue.
Radiant Historia features a unique battle system that utilizes a 3x3 combat grid. Strategy will play an important role, as your attacks will have greater impact on enemies in closer grid units, while enemies further away will take less damage. Larger enemies will take up more than 1 grid unit. Players will be able to strike more than one enemy at once as they change position. Players will also be able to force multiple enemies onto one grid unit with special attacks. When this happens, all attacks on that grid unit will hit all enemies there, allowing you finish off groups of enemies quickly.
The top screen displays a list of who will attack next, allowing the player to plan a strategy. When the player's party takes turns consecutively, the chance for a combo attack occurs. Combos deal greater damage allowing players to quickly take out an enemy. The player also has the option to rearrange the turn order of the characters in battle, in order to set up more combos. The downside to this is that after rearranging the turn order, your characters will be left vulnerable to attack for a few turns, taking more damage than normal. As a result, you must weigh the risks and rewards of switching the turn order.
While battling a gauge builds up known as a mana guage. Abilities for the mana gauge are acquired through events that happen in the story and become unlocked once the player goes into Historia after acquiring the item. The first mana gauage ability received is a move that can completely remove a turn from an enemy. All 3 characters in your fighting party build the gauge at their own pace depending the combo they have performed in.
The soundtrack was composed by Yoko Shimomura.
- RADIANT HISTORIA
- Mechanical Kingdom
- To the Battlefield
- Blue Radiance
- Forever Proud
- To the Future that Waits Ahead
- Beyond the Wilderness
- The Edge of Green
- Dreams Shrouded by a Cloud of Dust
- The Garden Where the Celestite Lies
- The Melody Connecting the World
- Unending Clear Blue Sky
- Shadows Dance in the Darkness
- The Red Locus
- Wildness and Toughness
- Where the Wind and Feathers Return
- Impending Crisis
- Interrupted Moment
- Memories of the World
- An Earnest Desire of Grey
- Affectionate Moment
- -HISTORIA- (instrumental version)