Can anyone tell me all the different ways to duplicate Pokemon and items?

To do this you need a Pokemon with thief (we'll call it Pokemon A) and a ditto.
Give the item you want to duplicate to "A".
Get into a double battle and have "A" and ditto out first.
Use transform on "A" and ditto SHOULD transform into "A" with the item "A" was holding (i think?).
Use thief on ditto and you should now have two of said item.

If this doesnt work give ditto the item instead.
You can test the top one by using a berry.

I hope this helps!


Cheese456

To dupilacte, you have to do something with the GTS

Well, there IS one way that I know of to clone pokemon. If you attach an item to it, it'll be cloned along with it. Ok, first put the Pokemon you want cloned in the GTS. Again, if you want an item cloned, now is the time to attach it. Alright, now when the Pokemon is in the GTS, you're going to want to move away from your wireless internet source, because that little timer-type thing on the lower right of the top screen, you're going to want it to make it to eight complete spins. Alright, now withdraw the Pokemon you put in the GTS in there. Now, the little timer, when it makes it to eight spins, shut your Nintendo DS off. Now turn your DS back on. After getting past the title screen it'll tell you that the save file is corrupted and the previous file will be loaded.
>>>>>>>>>>>THIS IS SUPPOSED TO HAPPEN. YOUR GAME IS 100% SAFE<<<<<<<<<<<<<<<<<<<
If done right, the Pokemon should be in the GTS and in your party.