Only Pokémon with the black clover (also known as the Alola symbol) may participate, meaning that only Pokémon obtained in the Generation VII games can be used. Pokémon transferred from previous generations cannot be used.
A new feature in Pokémon Sun and Moon allows players to download rule sets, so players can down this ruleset to practice with the 2017 VGC rules. This can be done in Festival Plaza in the games. The 2017 VGC rules are now available for download.