of Pokémon, the battle is over. When a human-controlled Pokémon wins a battle, the Pokémon gains experience. Enough experience will earn that Pokémon a higher level, which grants upgraded stats—attack, defense, special attack, special defense, HP, and speed—and sometimes grant new moves. Certain battles allow for two-on-two battles; certain moves were designed to support partners while other moves are capable of attacking two or more Pokémon. Unlike Ruby and Sapphire which had the player fight two specific trainers, Emerald allowed for the player to have a 2-on-2 battle with two trainers both of whom they could usually battle separately. Every Pokémon has an ability that often aides in battle, such as abilities that make a Pokémon more powerful if they are close to fainting. Wild Pokémon encountered by players can be captured using items called Poké Balls, which have a greater chance of success the weaker the wild Pokémon is. Players can battle and trade with others using any of the third generation Pokémon games including Emerald, Ruby, Sapphire, FireRed, and LeafGreen by linking their Game Boy Advance systems together. This can be accomplished either by using a Game Boy Advance Link Cable or by use of the wireless adapter that was bundled with FireRed and LeafGreen. It is also compatible with Pokémon XD: Gale of Darkness. This allows players to trade for Pokémon not normally obtainable in Emerald. Aside from the traditional battle and overworld style, players' Pokémon are also able to participate in Pokémon Contests where they can try and win in five contest categories: "Cool", "Beauty", "Cute", "Smart", and "Tough" competitions. The players' characters are given a device early on called the PokéNav, which allows players to view the world map, check their Pokémon's contest stats, and make and receive phone calls with trainers that they have met with whom they can chat or plan a battle. This replaces a function called "Trainer's Eyes", which allows players to register certain trainers and see when they are in the mood to battle. This also allows players to re-battle Gym Leaders, an ability not found in previous Pokémon games. Emerald includes several other new features and changes such as animations of Pokémon in-battle and an area called the Battle Frontier which is an expansion of the Battle Tower found in previous games. A man whom players encounter several times throughout the game will eventually allow them to access the