Dark Law takes places during a period of uncertain prosperity returned after a tragic war first struck the world 300 years ago. A demon comes in to kidnap Refia. She must be rescued and King Daruk of Amugnon must be defeated in order for true prosperity to return. Towns are navigated through a menu system and up to four characters can form an adventurers' part. The battles in this video game are similar in form to Treasure Hunter G--they use a power bar that drains with movement and action, except that battles are not restricted to 16x16 squares.

Like a game that popularized the trend, Chrono Trigger, the game has multiple endings. The game is considered to be less linear than its Japanese role-playing game counterparts.