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Note: In singleplayer worlds where cheats were not enabled at creation, they can be enabled on a temporary basis by opening the current game session to LAN play ( Esc → "Open to LAN", then "Allow Cheats" button and "Start LAN World"). You do not actually need to be on a LAN or have others join. This is not permanent, but will allow the use of commands until you quit the world, and changes you make via commands (items spawned, etc.) will be saved with the world. You can do this each time you start playing the world again. Note that this will disable game pausing for the duration, so while open to LAN, you should get somewhere safe or reload your world before using the Game Menu. Remember that you can disable your LAN world by reloading the world.