4. Type in "/gamemode" (without the quotes) followed by a space, and the mode you want to switch to (Creative, Survival, Adventure, or Spectator), then hit the Enter key. So, for example, if you want ...

Minecraft has evolved a lot in the last 10 years, adding a handful of game modes for variety. Here is how to switch between them on the fly.

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.