Final Fantasy VI focuses on a conflict between the Gestahlian Empire conquering the world and a rebel faction opposed to them known as the Returners, taking place in a fantasy steampunk-style world. The Empire has acquired great power by experimenting on captured espers, magical creatures of legend. The Returners seek magical power to fight the Empire on equal terms, and an amnesiac former imperial soldier, Terra Branford, proves key to both sides for understanding magic and espers.

The game gives players up to fourteen playable characters, the largest cast in the series, and features the Active Time Battle pseudo-turn based menu command system. A party can consist of up to four characters, though some events require the player to assemble three different parties of up to four and switch between them. Each character has a unique command ability, such as Terra's Trance, Locke's Steal, Edgar's Tools or Sabin's Blitz, and can also learn Magic spells from earning AP from battles with magicite equipped. Each character's rare Desperation Attack will randomly activate after using the Attack command when at critical health.