Pokémon Blue

After venturing alone into deep grass, a voice warns the player to stop. Professor Oak, a famous Pokémon researcher, explains to the player that wild Pokémon may be living there, and encountering them alone can be very dangerous. He takes the player to his laboratory where the player meets Oak's grandson, a rival aspiring Pokémon Trainer. The player and the rival are both instructed to select a starter Pokémon for their travels out of Bulbasaur, Squirtle, and Charmander. Oak's Grandson will always choose the Pokémon which is strongest against the player's starting Pokémon. He will then challenge the player to a Pokémon battle with their newly obtained Pokémon, and will continue to battle the player at certain points throughout the games.
While visiting the region's cities, the player will encounter special establishments called Gyms. Inside these buildings are Gym Leaders, each of whom the player must defeat in a Pokémon battle to obtain a total of eight Gym Badges. Once the badges are acquired, the player is given permission to enter the Pokémon League, which consists of the best Pokémon trainers in the region. There the player will battle the Elite Four and finally the new Champion: the player's rival. Also, throughout the game the player will have to battle against the forces of Team Rocket, a criminal organization that abuses Pokémon. They devise numerous plans for stealing rare Pokémon, which the player must foil.