Welcome to the world of Pok�mon, one filled with wild Pok�mon and the people who attempt to tame them. You are Ash Ketchum, a boy on a quest to become the best Pok�mon trainer in the world. Professor Oak, the leading authority on Pok�mon, has given you your choice of three tame Pok�mon in exchange for your helping him catalog and document every Pok�mon in the world.
But to catalog a Pok�mon, you have to capture it, by first beating it up with one of your trained Pok�mon, and then hitting it with an empty Pok� Ball. As your tame Pok�mon gain experience in battle, their abilities improve and they earn access to new attacks. Sometimes they even evolve into more advanced Pok�mon. Aside from capturing wild Pok�mon and evolving your own, you can catalog new Pok�mon--the only way to gather some Pok�mon--by trading with another Pok�mon player using either a link cable or the Game Boy Color's infrared system. Pok�mon gained through trades learn and evolve faster, and trading is the only way to capture all 151 Pok�mon, since each Pok�mon game has certain Pok�mon missing. So if you own Red and want to have a complete set of Pok�mon, you must find a friendly Blue or Yellow owner and arrange a trade.