How to Get a Mew in Emerald Without Cheats or Warps

Insert the copy of "Pokémon Emerald" into your Game Boy Advance. Connect the wireless adapter into the slots on each side of the game cart slot of your Game Boy Advance. The adapter should click into place and settle over the copy of "Pokémon Emerald."

Turn the Game Boy Advance system on and press "Start." Select "Receive Gift" from the main menu. If connected to the Wonder Spot, the adapter will begin downloading the item.

Press "Start" once the item has been received. Press "Start" at the main title screen and select "Continue."

Travel to Pacifidlog town and show the ferry attendant the Old Sea Chart. He will take you to Faraway Island, where you can battle and capture Mew.

Step onto Faraway Island once you dock. Since there is only one Mew in the game, you should save at this point so you can restart and try to capture it again if you accidentally defeat it.

Go into the grass on Faraway Island; Mew will appear. When it sees you, it will run off. Chase after it. After chasing Mew for a few seconds, it will be backed up against a wall and the battle will commence.

Use either a Psychic, Bug, Dark or Ghost-type Pokémon to battle Mew; Mew is a Psychic-type and is weak against these four types. Consider using a Pokémon that knows a sleep or paralysis inducing move to prevent Mew from attacking you.