Animal Crossing: New Horizons has only been out for a matter of days, but Nintendo is already hard at work patching out certain exploits. One exploit that's just been taken out of the game entirely is the item duplication glitch.
Patch 1.1.1 is now available to download for New Horizons. Over on the Japanese Nintendo website, the patch notes for the new update were published in full, where a "serious bug affecting game balance" has been entirely fixed.
It turns out this "serious bug" was the duplication glitch. While it was still active, this glitch allowed for two local multiplayer friends to put an item on a table, and if one player repeatedly turned the item, it would spawn multiple copies of the same item, which the other player could then take and claim for their own. You can probably imagine how this would have been used to game the system.
Note that it actually is possible to continue using the duplication exploit if you simply cancel the patch download for New Horizons on your Switch. You won't be able to play online without the new patch though (except for local co-op multiplayer with another person), and once you have installed it, the glitch is gone forever.
If you want a legitimate way to earn currency in Animal Crossing, then you can check out our complete New Horizons Bells guide. Alternatively, we have guides on how to change your front door, how to move buildings, and much more here at USgamer.