Pokémon Diamond and Pearl/Other Cheats

Cloning

 * Note: This may corrupt your save


 * 1) Enter the GTS (Global Trade Station).
 * 2) Deposit the pokemon that you want to clone.
 * 3) Select any lv 100 pokemon in exchange so no one will take your pokemon.
 * 4) Click yes to confirm trade.
 * 5) Once the Pokémon shows up and looks like its about to be put in a pokéball turn off your DS.
 * 6) Turn on your DS and reload the game.
 * 7) Check your party your pokemon should still be with you.
 * 8) Enter GTS and retrieve your pokemon that is stored inside.

More than six pokemon in Pal park

 * Do this to get all your pokemon from pal park in just 1 day
 * I'm using emerald and Spphire for this (Sapphire is the on I'm migrating from)
 * 1) Migrate from Sapphire
 * 2) Change time
 * 3) Insert Emerald and switch your DS back on again and load up your Pokemon Diamond as normal.
 * 4) Once loaded click the "migrate from Emerald"
 * 5) Follow the normal process to transfer Pokemon, YES –> YES.
 * 6) The game will then give you this message: "You are using a different Nintendo DS, or its internal clock has been altered. If the game's time setting is changed, you will not be able to migrate Pokemon for another 24 hours. Would you like to change your game's time setting to match the Nintendo DS?"
 * 7) Click YES and wait while the DS configures your Diamond game.
 * 8) After the game reloads the title screen, switch the power off to close the system.
 * 9) Remove the Emerald cart and insert Sapphire again.
 * 10) Start up the Nintendo DS and start Diamond as normal.
 * 11) Once the title screen has loaded select the "migrate from Sapphire"
 * 12) Now follow the normal process of migrating Pokemon, YES –> YES –> Select six Pokemon and then accept the migration.
 * 13) After you have migrated, go to Pal Park and capture all the Pokemon and repeat this trick to migrate again.

Keep doing that and you can migrate more than 6 pokemon a day.

Cloning Items
Note that this only works in the Japanese versions.
 * 1) Give the item you want to clone to a Pokémon that has the move Thief.
 * 2) Put that Pokémon first in your party and a Ditto in second.
 * 3) Battle a double-battle.
 * 4) Transform Ditto into the Pokémon that has the item.
 * 5) Use Thief against the Ditto and finish the battle.
 * 6) Now you must have two of that item.