Pokemon: Let’s Go, Pikachu / Eevee has new requirement system to challenge Gym leaders
Pokemon: Let’s Go, Pikachu and Pokemon: Let’s Go, Eevee are throwing in a new wrinkle to Gyms. Before you can challenge one, you’ll need to clear requirements presented at the entrance. The games will have a variety of requirements, including certain Pokemon types, levels, and plenty more.
One example is with Pewter Gym. Before you can challenge Brock, you’ll be asked to present either a Grass-type or Water-type Pokemon.
It seems that the Gym Guide will be ensuring that you meet the proper requirements. In the past, they were known for providing hints and tips for battling the Gym or its leader.