Unbreakable Blocks

Each unbreakable block is the counterpart of a vanilla block, covering natural materials and building materials. Blocks are changed with the Brush Converter Tools, which exist as size 1 and size 6 brushes in both unbreakable and normal forms. A brush converts a vanilla block into its unbreakable version, and the reverse brush converts it back, working on blocks within a range of 50 blocks around the player. Conversion is the main way the mod is used, so a world can be partly or fully fortified.

The mod was designed with roleplay servers in mind, where admins want structures that players can build and rearrange without destroying the surrounding map. Admins can keep a world persistent by making key areas unbreakable, while players keep the freedom to build within those limits. The idea draws on the DarkRP mod for Garry's Mod. The author reports that over 420 of 834 blocks are complete, and the full block list is available on Google Drive and Modrinth. Unbreakable Blocks is published for Forge only, in 0.0.6 for 1.20.1, and is licensed All rights reserved, so it is not open source. Every player and the server need a copy of the mod.