Overview#
The Default World Type mod is a specialized utility designed for modpack creators and server administrators. Its primary function is to override the default world generation setting in the "Create New World" menu. In standard Minecraft, the world type defaults to "Default." This mod allows the selection to be locked or defaulted to any other available type, such as Superflat, Large Biomes, Amplified, or types introduced by external mods like Biomes O' Plenty or Oh The Biomes You'll Go.

By automating the world type selection, the mod ensures that players experience the intended environment of a modpack without needing to manually adjust settings, which is particularly useful for skyblock, wasteland, or highly customized exploration packs.
Configuration#
The core of the mod's functionality is managed through a single configuration file. Upon the first launch of the game with the mod installed, a configuration file is generated in the config folder of the Minecraft directory.
Configuration File Details
- File Name:
defaultworldtype-common.toml(ordefaultworldtype-client.tomldepending on the specific sub-version). - Location:
/config/folder.
Config Parameters
The configuration uses the TOML format. The primary key used to control the mod is defined below:
| Key | Value Type | Default Value | Description |
|---|---|---|---|
defaultWorldType |
String | minecraft:normal |
Defines the Resource Location ID of the world type that will be selected by default. |
To change the default world type, the user must replace minecraft:normal with the appropriate ID for the desired world generation.
Supported World Type IDs#
To successfully configure the mod, the correct ID string must be used. Below is a list of standard Minecraft world type IDs and common modded IDs compatible with version 1.20.1.
Vanilla World Types
| World Type Name | ID String | Generation Style |
|---|---|---|
| Default | minecraft:normal |
Standard Minecraft terrain. |
| Superflat | minecraft:flat |
A flat world with no natural elevation. |
| Large Biomes | minecraft:large_biomes |
Standard terrain with biomes scaled up by 16x. |
| Amplified | minecraft:amplified |
Extreme height variations and floating islands. |
| Single Biome | minecraft:single_biome_surface |
The entire world consists of one chosen biome. |
Modded World Types
If you have world-generation mods installed, you can use their specific IDs. Common examples include:
- Biomes O' Plenty:
biomesoplenty:biomesoplenty - Skyblock Mods:
skyblock:skyblock(ID varies by mod) - Terraforged:
terraforged:terraforged

Mechanics and Behavior#
The mod operates by injecting a check into the GUI initialization of the "Create New World" screen.
Client-Side vs. Server-Side
- Client-Side: When installed on a client, the mod changes the default selection in the user interface. This is ideal for single-player modpacks.
- Server-Side: When installed on a dedicated server, the mod ensures that if the
server.propertiesfile does not specify alevel-type, the mod's configured default will take precedence during the initial world generation.
Interaction with Existing Worlds
This mod only affects the creation of new worlds. It does not alter the generation of existing chunks in a world that has already been created. If the configuration is changed after a world is generated, the new setting will only apply if a brand-new world is started.
Mod Compatibility
Default World Type is designed to be highly compatible with other mods. It does not modify the actual generation algorithms; it simply changes the pointer that tells Minecraft which algorithm to use. As long as the target world type is correctly registered in the game's registry, this mod can call it.
Items, Blocks, and Mobs#
As a technical utility mod, Default World Type does not add any of the following:
- Items: No new items or tools are added to the creative or survival inventories.
- Blocks: No new blocks or decorative elements are introduced.
- Mobs: No new creatures, entities, or NPCs are added to the game.
- Structures: No new structures are generated by this mod itself.
The mod's footprint is entirely code-based, focusing on the logic of world initialization rather than content addition.
Troubleshooting#
If the mod does not seem to be changing the world type, verify the following:
- ID Accuracy: Ensure the ID string in the config file is exact. For example,
minecraft:flatwill work, butflatorminecraft.flatwill fail and revert to the default. - Config Location: Ensure you are editing the config in the correct instance folder. If using a launcher like Prism or CurseForge, check the specific instance's config folder.
- Mod Conflicts: While rare, other mods that modify the World Creation GUI (such as custom UI overhauls) may override the selection logic of this mod.