Which Nintendo NES game first introduced battery-backed saving for players?

The Legend of Zelda was Nintendo’s first NES game to introduce battery-backed saving for players.

Released in Japan in 1986, The Legend of Zelda used a battery inside its cartridge to preserve a player’s progress after the console was switched off. This was especially important for a large adventure game, because its exploration, dungeon progression, item collection, and multi-session structure did not fit naturally into a single sitting.

Earlier NES titles generally required players to restart from the beginning or rely on password systems when they wanted to continue later. The Legend of Zelda’s save files made persistent progress a central part of the home-console experience. The Japanese cartridge supported three save files, giving multiple players separate places to record progress.

The game starred Link, who explored Hyrule while seeking the Triforce fragments and rescuing Princess Zelda from Ganon. It is sometimes confused with Metroid because both Nintendo series used exploration and password-style continuation in related eras, but The Legend of Zelda is the NES title associated with Nintendo’s first battery-backed save system.