Trainer Battle

Trainer Battles are an upcoming feature in Pokémon GO. Trainers will need to choose a league before going into a Trainer Battle, with each league having different maximum Pokémon CP limits.

Battle Leagues
There will be three Battle Leagues to choose from which include Great League, Ultra League, and Master League. Each Trainer will only be allowed to assign three Pokémon to a Battle League party.

Development
When designing Trainer Battles, Niantic wanted to create an experience that everyone could enjoy and ensure that different kinds of Pokémon can show their strengths! With Leagues in Trainer Battles, they hope to create a system that's accessible to many Trainers.