A Rotation Battle is a Pokémon Battle that is another three-on-three battle mode, where you can only choose one of your Pokémon out of the three out to attack each turn. You have to predict which Pokémon your opponent will use and what attack they'll use for the greatest success. This type of three-on-three battle is in addition to the regular three-on-three battle mode and the one revealed last month where you can constantly rotate the position of your Pokémon.
The Rotation battle involves three Pokémon where only the one in front can attack and take damage. In this type of battle, you can move Pokémon from the back and front and, unlike a from switch, this allows the use of an attack - At the cost of your opponent knowing what pokémon you have.