ModernDifficultyLocker

A lightweight mod that backports the difficulty lock feature from Minecraft 1.8+ to Minecraft 1.7.10, including the lock button and the confirmation screen.
It is designed to behave as closely as possible to the modern vanilla implementation while remaining fully compatible with classic 1.7.10 modpacks.

🌟 Details

ModernDifficultyLocker introduces the familiar difficulty lock toggle to the Options screen in 1.7.10.
Once a world is locked, the difficulty can no longer be changed through the in‑game menu, mirroring the behavior of newer Minecraft versions.

The mod stores the lock state per‑world inside the save folder, so each world can have its own difficulty and lock configuration.
This feature is especially useful for players or modpack authors who want consistent gameplay difficulty across a world’s lifetime.

Integration with CreateWorldUI

If CreateWorldUI is installed, this mod seamlessly integrates with it:

The vanilla difficulty button is replaced with a World Settings… button
Difficulty and gamerules can be configured together in a unified interface
The experience matches the modern world‑creation flow introduced in later Minecraft versions

Compatibility

Client‑side only — works exclusively in singleplayer (integrated server)
Does not modify server behavior
Safe to use when connecting to vanilla or modded servers
No server installation required

See the gallery for screenshots and UI previews.

🙌 Credits

The UI and behavior are inspired by the vanilla difficulty lock system introduced in Minecraft 1.8+.