Daibouken: St. Elmo's no Kiseki

Leon is a young boy of 16 who lives in Barcelona, and the son of the famous adventurer Fal Aventura. One day, the wreckage of his father's ship washes up on the shores of the city and, in order to find out what happened to his father, the young Leon sets out on a voyage of his own. Trusting that his father is still alive somewhere, Leon leaves to explore the world by sea, searching for the truth.

Daibouken: Saint Elmo's no Kiseki is a seafaring pirate-themed JRPG similar to Koei's Uncharted Waters series. The game is roughly divided up into two main sections: sea travel, and on-foot town exploration, which each also have their own dedicated mode of combat. On-foot combat plays out in standard JRPG style, with the player choosing an action for each member of their party and watching as the results play out. Naval combat on the other hand takes a semi-real-time format where the player directs each ship in their fleet, issuing commands to attempt to sink all enemy ships, then board the lead ship and take out the captain in standard combat.

Most towns are infested with monsters when first reached, and the monsters must be defeated before the player can explore the town properly. Towns contain many types of businesses, such as inns and shops, taverns where crewmen can be recruited, and shipyards where the player's ship can be upgraded in both offensive and defensive capabilities. In addition to equipping the ship's crew, the player must also ensure they have enough resources such as food and clean water for each voyage.