IN HARDCORE MODE: You Have to Pause and hit "Open to LAN" then hit "Allow Cheats" and set it to "ON" now, hit "Start LAN World", after this type "/gamemode survival" unquoted after that, save and exit to disable cheating!

Minecraft, But You Only Have 2 Regenerable Hearts. With This Datapack, Say Goodbye to full recovery, as the only way to get a full recovery is to eat a Golden Apple, Enchanted Golden Apple Or, Use a Totem of Undying. Extremely Difficult On Hardcore mode!