Is possible to trasnfer Pokemon from Red, Blue, and Green to Yellow?
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Go to any Pokémon Center with Pokémon Yellow and either Pokémon Red or Blue. There, you will find a Link Cable Club.
Connect the two Game Boys/Game Boy Colors/Game Boy Advances with a Link Cable.
Have both games speak to the receptionist. Save when prompted, and select the "Trade Center" option.
Go inside of the Trade Center in both games and face the center of the table.
Press A to start the trade. Select Pikachu for trade in Pokémon Yellow, and another Pokémon in Red or Blue. Press A to make the trade.
In Pokémon Red or Blue, use a Thunder Stone on Pikachu to evolve it. If you don't have a Thunder Stone, you can buy them in the Celadon City department store.
Repeat steps 1 through 5 to trade Raichu to Pokémon Yellow.