Long ago, an evil dragon named Keela was imprisoned inside a magical dungeon. However time has passed and the magic that sealed the dragon away is weakening. The Drasle family decides that it's time to destroy the dragon once and for all. However only one weapon is capable of doing this, the Dragon Slayer, which is itself sealed away by four magical crowns. The Drasle family decides to take on this quest, and will use every member of the family in order to accomplish it.

Legacy of the Wizard is a side-scrolling action platform game with light role-playing elements. The player chooses a character from among five different members of the Drasle family. The choices are: Xemm the father and woodcutter, Mayna the magic-using mother, Roas the brave warrior son, Lyll the athletic daughter and Pochi the domesticated monster-pet. Each character has unique abilities (including attack and jumping abilities) and can only use certain items from those collected. Players can travel back to the Drasle household at any point to change characters.

The object of the game is to enter the large dungeon, itself divided into 5 areas, collecting a variety of items (which as mentioned, can only be used by particular characters) and use them to progress through the dungeon, defeating monsters. Power-ups dropped by monsters include gold, keys, health-restoring bread, magic-restoring potions and health-damaging poison. Gold can be spent on items and other power-ups that are available at various shops hidden inside the dungeon. The player must eventually defeat the four bosses guarding the crowns that seal the Dragon Slayer and then use that weapon to defeat the Kress.