Pokémon Yellow is an enhanced version of the Game Boy games Pokémon Red and Blue. Like its predecessors, it is a third-person, overhead perspective and consists of three basic screens: an overworld, in which the player navigates the main character; a battle screen; and a menu interface, in which the player configures their party of Pokémon, items, or gameplay settings. The player uses their Pokémon to battle other Pokémon. When the player encounters a wild Pokémon or is challenged by a trainer, the screen switches to a turn-based battle screen that displays the engaged Pokémon. During battle, the player may select one of up to four moves for their Pokémon to use, use an item, switch their active Pokémon, or attempt to flee. Pokémon have health points (HP); when a Pokémon's HP is reduced to zero, it faints and can no longer battle until it is revived. Once an enemy Pokémon faints, the player's Pokémon involved in the battle receive a certain number of experience points (EXP). After accumulating enough EXP, a Pokémon will level up. A Pokémon's level dictates its physical properties, such as the battle statistics acquired, and the moves learned.