The Legend of Zelda was the first Zelda game, introducing millions of people worldwide to a world whose mysteries would unravel for years to come. It was released in Japan in 1986 for the Famicom Disk System, and then later on a special gold cartridge for the Famicom itself. The North American release on the NES saw the title sell over 6.5 million copies on that console alone.
As the first NES adventure game of such scope and diversity, LoZ was the first cartridge to incorporate a battery back-up facility. This was desperately needed, as the main overworld (128 screens of seamless adventuring) was far bigger than that of other adventure games at the time, not forgetting the eight challenging dungeons that formed the meat of the game. There were an incredible number of different enemies (over 25), all with their own graphics and AI, plus a range of weapons and items of a scope previously unimagined.
In the game you play Link, an elf-like hero with a destiny to protect Hyrule from evil. A powerful monster named Ganon, an underworld king with a clouded past, has broken free from his imprisonment in the Sacred Realm, slowly gathering forces in South West Hyrule. In order to take the whole of Hyrule for himself, however, he must have the Triforce of Wisdom. Princess Zelda, its owner, has scattered the eight pieces across South West Hyrule and it is your job as the hero to find and reunite them.
While LoZ created the mould for the action adventure genre, the series would go on to include heavier RPG elements. The story was initially weak, but the opportunity to freely explore every nook and cranny of this great foreign land was enough to propel gamers through the adventure.