The only way to switch an existing world to Hardcore mode is to use a third-party app to edit the game's files. How to change game modes in 'Minecraft: Java Edition' 1.

If you want to change simulation distance in Minecraft in Bedrock, Java, or Multiplayer to get a better gaming experience, this guide is for you.

Here's how to use the /gamemode command in "Minecraft: Java Edition" and "Minecraft: Bedrock Edition." Quick tip: Note that you can't use this trick to switch to Hardcore mode. The only way to switch ...