The game takes place in a region called Pasio, which is an artificial island. Various Pokémon trainers come to Pasio to compete in the Pokémon Masters League. The player starts with a Pikachu as they recruit other trainers to take on the league.
Unlike most Pokémon games, battles in Pokémon Masters are fought exclusively in three vs. three battles, with the player teaming up with two other trainers to battle a group of three. Battles are fought in real time, with trainers attacking only if the Move Gauge is full enough. The Move Gauge fills as time passes. Trainers can also perform moves known as Sync Moves, which are similar to the Z-Moves found in Pokémon Sun and Moon. Trainers in this game also have their own moves.
Each trainer has one Pokémon used in battle. The pairs of trainer and Pokémon are known as Sync Pairs.
(Note: The Pokémon listed is the one that the trainer starts out with.)
In addition, the following characters have been seen in promotional material for the game or in the game itself, but they are not currently playable.
|Trainer||Pokémon (if any)||Base Potential (If any listed)|
|Professor Kukui||Lycanroc (Midday Forme)|