Pokémon Silver Version is a role-playing game developed by Game Freak for the Game Boy Color, released in 1999. As part of the second generation of the Pokémon series, it expands the Pokédex to 251 species, including legendary Pokémon such as Mew and Celebi. Set in the Johto region, players take on the role of a young trainer collecting Gym Badges, challenging Gym Leaders, and battling the remnants of Team Rocket. A day-and-night cycle divides time into morning, day, and night, affecting which Pokémon appear, while a weekly calendar triggers special encounters, such as Pokémon that only show up on specific days in certain locations. The in-game watch and PokéGear phone system let players listen to broadcasts and keep in touch with trainers they meet on their journey, receiving notifications about rare Pokémon sightings, useful items, and rematches. After completing the Johto adventure, players travel to Kanto, take on its Gym Leaders, and face the previous protagonist Red deep inside Mt. Silver.