Action Replay codes enable a player to encounter shiny Pokémon in the wild, change a captured Pokémon's traits or hatch a shiny Pokémon from an egg. Using Action Replay to obtain shiny Pokémon is not a practice sanctioned by Nintendo, so players may have difficulties trading these Pokémon or moving them to other games.
Action Replay, formerly known as GameShark, released several different codes that produce shiny Pokémon. These codes vary depending on which Pokémon game is being played. For example, entering 77BFC010 FE8DCA24, B2C5E8F4 074034FB, 9C1FE7D6 B07AE5A0, 63149984 A8C01E2C while playing Pokémon Emerald Version causes the player to encounter only shiny wild Pokémon. If the code is entered when playing a different version, the code does not work and could damage the save file.
The Pokémon that the player encounters in the wild can also be modified, giving the player an opportunity to catch a shiny version of any Pokémon. Special event Pokémon and shiny versions of them can also be unlocked with the Action Replay.
Any Game Boy or DS version of Pokémon that was released after Gold and Silver already has shiny monsters in the game. The odds of encountering one in the wild are about 1 in 8,192 in Pokémon X and Y.