HardGrind

Once a world is locked, players cannot leave survival or switch difficulty mid-run. Commands such as gamemode, teleport and gamerule changes, along with datapacks and console edits, are blocked or put back on the next tick. Creative and spectator switches are reverted at once, and dead players in Hardcore stay spectators. Key gamerules including keepInventory, mobGriefing, doDaylightCycle and naturalRegeneration are restored if changed, so the run keeps its original rules.

A running record goes into the hardgrind log file, listing deaths, mob kills and free-text notes, and it also marks milestones such as a complete beacon, each stamped with the in-game day and total play time. A world saved under HardGrind will not open without it, and the mod keeps restored backups of old copies in case a save is caught mid-write or a player force-quits. Known cheat clients and X-ray mods still cannot bypass a locked world. The mod is server-side only, so players join without installing it, and it requires Fabric API.