Pokémon X and Y/Features/Horde Encounters

It is now possible to encounter several wild Pokémon at once. Up to five wild Pokémon will battle against one of the player's Pokémon. These battles offer a lot of experience. Some attacks, such as, are shown to hit all five of the opposing Pokémon. However, the player's Pokémon must withstand attacks from all five of the opposing Pokémon each turn.