The Legend of Zelda incorporates elements of action, adventure, and role-playing games. The player controls Link from a flip-screen overhead perspective as he travels in the overworld, a large outdoor map with varied environments. Link begins the game armed only with a small shield, but a sword becomes available to Link after he ventures into a cave that is accessible from the game's first map screen. Throughout the game, various characters aid Link by giving or selling equipment and clues. These people can be found in caves scattered throughout the overworld; some are readily accessible, while others are hidden behind obstacles such as rocks, trees, and waterfalls. Barring Link's progress are creatures he must battle to locate the entrances to nine underground dungeons. Each dungeon is a unique, maze-like collection of rooms connected by doors and secret passages, and guarded by monsters different from those found on the surface. Dungeons also contain useful items which Link can add to his arsenal, such as a boomerang for retrieving distant items and stunning enemies, and a recorder with magical properties. Link must successfully navigate through each of the first eight dungeons to obtain all eight pieces of the Triforce of Wisdom. Once he has completed the artifact, he can enter the ninth dungeon to rescue Zelda. Apart from this exception, the order of completing dungeons is somewhat left to the player, although they steadily increase in difficulty and some of them can only be reached or completed using items gained in a previous one. In addition, the entrances of the three highest-level dungeons are hidden. Link can freely wander the overworld, finding and buying items at any point. This flexibility enables unusual ways of playing the game. For example, it is possible to reach the final boss of the game without ever receiving the sword. After completing the game, the player has access to a more difficult quest, officially referred to as the "Second Quest" with new dungeon locations/layouts, different item placements, and stronger enemies. Although this more difficult "replay" was not unique to Zelda, few games offered entirely different levels to complete on the second playthrough. The Second Quest can be replayed each time the game is completed and can also be accessed at any time by starting a new file with the name "ZELDA".