The Legend of Zelda (video game)
"The Legend of Zelda" is considered a spiritual forerunner of the modern role-playing video game (RPG) genre. Though it is often not considered part of the genre since it lacked key RPG mechanics such as experience points, it had many features in common with RPGs and served as the template for the action role-playing game genre. The game's fantasy setting, musical style and action-adventure gameplay were adopted by many RPGs. Its commercial success helped lay the groundwork for involved, non-linear games in fantasy settings, such as those found in successful RPGs, including "Crystalis", "Soul Blazer", Square's "Seiken Densetsu" series, "Alundra", and "Brave Fencer Musashi". The popularity of the game also spawned several clones trying to emulate the game.
Overworld
While previous games have featured overworlds, one of the earliest console games to feature an overworld is the Nintendo Entertainment System game "The Legend of Zelda". Gameplay in "Zelda"s overworld was virtually identical to that of its nine underground dungeon levels, offering a top-down perspective and including access to caves, bridges, mazes, shops and waterfalls as well as lurking dangers that range from enemies to tumbling rocks. Much of the immediate gameplay takes place in the overworld, and the diversity of terrain (as well as the sheer size of the overworld itself) ensures that the player will spend as much time exploring and searching above ground as they will below (or in any of the areas listed above). The concept of an overworld also offered a nonlinear gameplay experience; some believed this would cause the player to become confused and not know where to go, a sentiment which has endured as overworlds have become larger and more complex.