Random Layers
by KoleH
Random Layers applies configurable block layers to terrain generation at fixed Y-levels, and the layers are repeatable for each world seed and dimension.
What it does
Random Layers changes how terrain is generated by placing block layers at chosen heights. Each layer is drawn from a pool that can hold both vanilla and modded blocks, and the same world seed and dimension always produce the same result. Generated structure blocks that sit in the replaced Y-range are swapped as well.
The mod needs Fabric API on Fabric. It is a server-side only mod, so players join without installing it and the server alone runs it. Files are published for Fabric, Forge and NeoForge, all for 1.20.1, with the 1.0.0 release dated 2026-03-28 on each loader. Random Layers is open source under the MIT License, and its source code, issue tracker and wiki are public.
Key features
Forced layers at set heights
Block layers are placed at configured Y-levels, replacing the terrain generated at those heights.
Configurable block blacklists
Blocks can be excluded from replacement by exact block ID or by namespace, and a blacklist can be set in the config.
Protected block entities
Blocks with block entities are skipped during replacement, and critical vanilla blocks are kept in place.
Structure handling toggles
Options control whether generated structure blocks in the affected Y-range are replaced or left unchanged.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Requirements
Dependencies declared by the latest file for each loader.
Required 1
Use cases
Custom underground layering
A server owner can build a world with stacked strata drawn from modded blocks, while keeping ores and chests intact.
Reproducible modpack worlds
Because layers depend only on the world seed and dimension, a modpack keeps the same terrain for every new world made from one seed.
Who it’s for: Server owners and modpack authors who want custom terrain layers on 1.20.1, with a deterministic result tied to the world seed.
How it compares
Forced seed is a Forge mod for 1.20.1 that is open source under the MIT License and is server required, with the client optional. Minecraft but Chunks are Random is published for Fabric, Forge and NeoForge across 1.20 – 26.2, is server required with the client optional, and is not open source. Random Layers is server-side only, so players do not install it.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Random Layers | Fabric, Forge and NeoForge | 1.20.1 | Server-side only | 2026-03-28 |
| Forced seed | Forge | 1.20.1 | Server required, client optional | 2025-08-22 |
| Minecraft but Chunks are Random | Fabric, Forge and NeoForge | 1.20 – 26.2 | Server required, client optional | 2026-06-20 |
Questions
Does Random Layers need Fabric API?
Do players need to install Random Layers?
Will the same seed always give the same layers?
In the catalog
Random Layers is one of 8,515 World generation mods on ModsFinder, and one of 4,027 World generation mods for Fabric. 34,764 mods support Minecraft 1.20.1.
More from KoleH
Similar mods
What the author says
Features - Deterministic generation per world seed + dimension - Replaces terrain and generated structure blocks by Y-level - Supports vanilla + modded blocks in the layer pool - Configurable blacklist support: > - Namespace blacklist (example: create) > - Exact block ID blacklist (example: minecraft:tnt) …
Official listing
- Modrinth page
- modrinth.com/mod/random-layers
- Owner
- KoleH
- Published
- 2026-03-27
- Updated on Modrinth
- 2026-03-28
- Facts verified
- 2026-10-15