How to dupe in IP games:
First, get a noob to host for you. Tell him to stay in the game.
Before you join or pick a character, create a directory in C:\program files\diablo II\save called Temp.
Copy ALL files related to the character into this directory. Join the IP server and pick the character. Then when you are in the game, drop the items you want to copy. Then select Save and Exit. Now, go into your Temp directory and cut all the files from the Temp back to save, this will "send your character back in time". Rejoin the ip, if it works you should still have the items you had in your hand!! Go over and pick up the items you dropped earlier. Congrats you duped
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Be warned, do not overwrite data while you have some visual on your character, or you will screw him or her up and crash the game. PluGy makes things easier, but there have been issues using it
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