The basic mechanics of Ruby and Sapphire are largely the same as their predecessors'. As with all Pokémon games for handheld consoles, gameplay is in third-person, overhead perspective and consists of three basic screens: a field map, in which the player navigates the main character; a battle screen; and the menu, in which the player configures their party, items, or gameplay settings. Players begin the game with one Pokémon, and can capture more using Poké Balls. They can also use their Pokémon to battle other Pokémon. When the player encounters a wild Pokémon or is challenged by a trainer to a battle, the screen switches to a turn-based battle screen where the Pokémon fight.[1] During a battle, the player may use a move, use an item, switch their active Pokémon, or flee, although fleeing is not an option in battles against trainers. All Pokémon have hit points (HP); when a Pokémon's HP is reduced to zero, it faints and cannot battle until it is revived. If the player's Pokémon defeats the opposing Pokémon (causes it to faint), it receives experience points. After accumulating enough experience points, it will level up; most Pokémon evolve into a new species of Pokémon when they reach a certain level.[2]
Apart from battling, capturing Pokémon is the most essential element of Pokémon gameplay. During a battle with a wild Pokémon, the player may use a Poké Ball on them. If successful, the Pokémon will be added to the player's active party, or stored if the player already has the maximum six Pokémon in their party.[3] Factors in the success rate of capture include the HP, status effects such as Paralysis or Sleep, and the strength of the Poké Ball used: the lower the target's HP and the stronger the Poké Ball, the higher the success rate of capture is.[4] Other trainers' Pokémon cannot be captured.