The kingdom of Altenia was a peaceful place until monsters began to roam the land, terrorizing its inhabitants and striking fer into the hearts of bravest warriors. Only one of them stood up to the challenge: entrusted by the king with an important mission, the lone knight must find the reclusive mage Gladrif and figure out a way to get to the source of evil.

Kalin no Tsurugi is an action role-playing game. The player navigates the protagonist on a top-down overworld, entering towns and other locations represented by icons. Monsters are visibly moving on the field, a contact with an enemy leads to a separate battle screen, on which the player character and the enemy fight each other. There is no attack button in the game, damage is inflicted by bumping into the enemy, preferably from the side or rear. Weapons, armor and items can be bought in towns and villages.