How to Lock an Item or Block Behind a Stage

Editing the stage config

Game Stages reads its restrictions from config files, not from in-game commands. Locate the Game Stages config directory inside your instance's config folder. You will find separate files or sections for items, blocks, mobs, and recipes. Each entry maps a stage name to a list of registry names.

To lock an item, add its registry name (for example, the namespaced ID shown in JEI or the item's tooltip with advanced info enabled) under the stage you want to gate it behind. A player without that stage will be unable to use, craft, or pick up the item depending on which restriction list you placed it in. Blocks work the same way: list the block's registry name under the stage, and players lacking the stage cannot place or break it.

Testing your changes

After saving the config, reload it with the reload command rather than restarting the game. Then use the stage command to add and remove the stage from yourself and observe the effect. If nothing changes, double-check the registry name spelling and that you edited the correct list. Remember that restrictions are enforced server-side, so on a multiplayer server the config must be present on the server, and clients only need it for display purposes.