Phantasy Star III is a sequel to the previous game in the series, Phantasy Star II, although the connections to other games in the Phantasy Star series are not immediately evident. Gameplay is similar to the games before it in the series, with combat still being turn-based and battles randomly occurring. Players must explore both overworld maps and dungeons in order to progress through the game.
Phantasy Star III mostly follows the traditional roleplaying game formula seen throughout the series, with exploration of several 2-D worlds, character recruitment, and random enemy encounters using a turn-based battle system. Unlike previous games, the series staple of "techniques" play a diminished role in combat, which is ironic considering the role they play in differentiating the game's two major factions - with techniques being exclusive to Layans, and viewed as "evil magic" by the Orakians.