 In "Sword" and "Shield", a Trainer must complete a Gym Challenge, which is essentially a minigame, in order to continue through the Gym.Also, this will earn the former a Technical Machine (prior to "Sun" and "Moon"), which allows the player to teach their Pokémon a certain move.It also usually enables the player to utilize the overworld effects of one of the various Hidden Machines, such as the ability to cross bodies of water with the move Surf or the ability to remove some trees from paths with the move Cut.