First, take the item(s) you want to duplicate to your friend's world. Then, drop the item and have your friend pick it up. Now, turn off your game [NOT YOUR FRIEND!]. Then, you'll still have the item and so will your friend. You can chain this method to have lots of rare items, and even duplicate money.
Thats one way to duplicate items but i know another...You drop a sratchcard then a noob item and your item you wanted to duplicate or its the other way around, your good item then the noob item, i kinda forget because i stopped playing for abit.
Tezzdev
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