IGN: TheMiner30 Server: SG Detailed: I am unable to provide a video or screenshot. However, I can try to go into as much detail as possible. First off, if you have a really good piece of equipment, you can right click it to put it on if it's armor, to defend if it's a sword, or nothing if it's an axe. I have not yet tried it with the bow. Next, place any other item. Food is the easiest to work with it, however any other cruddy item will work just fine. I'm not sure about armor that you don't have, but I'm sure about armor you do have on and another cruddier version (Leather or gold) to be duplicated. Next, all you have to do is hold down the right mouse button, or mouse2. Finally, after a few seconds, the first item you previously right clicked on will be in your inventory. You cannot get the crappy item you used to be duplicated back, but you will have a duplication of the same, most likely powerful first item you used in your inventory. I hope I explained this well enough.
The item isn't actually duplicated, the client and server inventory are out of sync. Same issue as this one: http://itsjerryandharry.com/threads/sg2-bug.79919/#post-773046