DISCLAIMER: I do not encourage or condone cheating, it ruins the game for yourself and others. This information is for informational purposes only.
It’s not too difficult to duplicate items on singleplayer or multiplayer, I am sure these glitches will be fixed eventually. Generally the more these things get abused, the quicker they get fixed.
To duplicate any item in singleplayer:
- Have whatever you want to be duplicated in a chest and ‘save and exit’ your world
- Go my documents/my games/terraria/worlds and copy your world to another folder/desktop
- Go in the game and place things you want duplicated into your inventory
- Leave the game
- Replace your current world with the backup you just made
- You now have the original item/stack both in your inventory and in the chest. This works because your inventory and the world is saved separately.
Note: Turn off fullscreen so you can quickly switch between the folder/desktop and the game.
To duplicate items in multiplayer:
- Login to the server you usually play on
- Pick up every item you want to duplicate, so they remain in your inventory
- Disconnect via Inventory menu (default key: ‘Esc’)
- Reconnect to the server
- Move the items you want to duplicate into a Chest (won’t work with Piggy Bank)
- Press Alt+F4 to close the game without saving your changes
- Now go back into the server, and you’ll have the items you moved into the Chest in your inventory and inside the chest. Since the game does not save your inventory (which is saved in a separate file) because you closed it by using Alt+F4 and thus preventing any saving, you keep your items, while the server keeps the items inside the Chest since they are “saved” on the servers files.