Dimension Separator
Minecraft Forge mod (1.20.1) for modpack makers — restrict which mods can interact with which dimensions. Block mob spawning, loot tables, world generation and item usage per dimension via a simple JSON config.
- Loaders
- Forge
- Downloads on Modrinth
- 247
- Followers on Modrinth
- 0
- versions
- 2
- Updated
- April 12, 2026Apr 12
- Published
- in 2026
At a glance
Install on the server only; players don't need it
Dimension Separator
This mod is created to separate what can appear in wich dimension. Tested on Minecraft 1.20.1 with Forge 47.1.3+.
What does it do?
I wanted to make a RP server where all the "magic" was forbiden in the overworld for lore purposes but I struggled to prevent some structures to appear in the overworld while still be in my custom dimension.
So I tried to create a mod to help me just do that.
It's still in testing but you can use a simple json config to tell the mod what exactly you want to let appear in wich dimension.
For each dimension, you can blacklist or whitelist mod namespaces to block:
- World generation features (ores, plants, structures...)
- Mob spawning
- Loot tables (chests, mob drops...)
- Item usage (right-click on blocks, in the air, or on entities)
- Structure generation
Configuration
The config file is located at config/dimensionseparator.json.~~~~ Here is an example :
{
"dimensions": {
"minecraft:overworld": {
"mode": "blacklist",
"bypassLevel": 2,
"namespaces": ["ars_nouveau", "iceandfire"],
"blacklistedIds": ["minecraft:zombie"],
"whitelistedIds": ["ars_nouveau:bookwyrm_familiar"],
"features": true,
"mobs": true,
"loot": true,
"items": true,
"structures": true
}
}
}Fields
| Field | Type | Description |
|---|---|---|
mode | string | "blacklist" to block listed mods, "whitelist" to allow only listed mods |
bypassLevel | int | Minimum operator level allowed to /summon blocked entities (-1 or absent = no bypass) |
namespaces | string array | Mod IDs to block or allow depending on mode |
blacklistedIds | string array | Specific IDs always blocked, regardless of mode (e.g. "minecraft:zombie") |
whitelistedIds | string array | Specific IDs always allowed, regardless of mode (e.g. "ars_nouveau:bookwyrm_familiar") |
features | boolean | Block world generation features (ores, plants...) from listed mods |
mobs | boolean | Block mob spawning from listed mods |
loot | boolean | Block loot tables from listed mods (chests, mob drops...) |
items | boolean | Block item usage (right-click) from listed mods |
structures | boolean | Block structure generation from listed mods |
Setting a category to false disables blocking for that category, even if the namespace is listed.
Known Limitations
/locateon a blocked structure will search indefinitely without result. This is vanilla Minecraft behavior when no matching structure exists in the dimension.- Client-side keybinds (e.g. opening a mod's GUI with a custom key) are not blocked — only right-click interactions are covered. In practice, opening an interface without being able to interact with the dimension is harmless.
- Item usage via custom keybinds is client-side and cannot be intercepted server-side.
Compatibility
This mod uses Mixins and event handlers and should be compatible with most Forge mods. If you encounter a conflict, please open an issue.
Issues & Contributions
Found a bug or have a suggestion? Open an issue on GitHub.
FAQ
How to install Dimension Separator?
Install Forge for your Minecraft version, download Dimension Separator for the same version and loader, put the file into the mods folder and launch the game with the loader profile.
Which Minecraft versions does Dimension Separator support?
Dimension Separator has builds for Minecraft 1.20.1–1.20.6.
Is Dimension Separator needed on the server?
Server only — players don't need to install it