Heroes of Might and Magic III: The Restoration of Erathia is a turn-based strategy game. It is the third installment of the Heroes of Might and Magic series. The game's story is first referenced throughout Might and Magic VI: The Mandate of Heaven and serves as a prequel to Might and Magic VII: For Blood and Honor. The player can choose to play through seven different campaigns telling the story, or play in a scenario against computer or human opponents.

The gameplay is very similar to its predecessors in that the player controls a number of heroes that command an army of creatures inspired by myth and legend. The gameplay is divided into two parts, tactical overland exploration and a turn based combat system. The player creates an army by spending resources at one of the eight town types in the game. The hero will progress in experience by engaging in combat with enemy heroes and monsters. The conditions for victory vary depending on the map, including conquest of all enemies and towns, collection of a certain amount of a resource, or finding the grail artifact.