Compatibility
Minecraft: Java Edition
Platforms
Supported environments
Tags
Creators
Details
OresReduced
OresReduced makes mining matter again. It lowers ore world generation so that resources are scarcer and more valuable — fewer veins, smaller veins, and rarer large veins — across the Overworld and the Nether. Perfect for survival servers, hardcore worlds, and any pack that wants a slower, more rewarding progression.
It is lightweight (a few KB), server-friendly, requires no dependencies (no Fabric API needed), and is fully configurable.
✨ What it does
By default (matching a classic 0.5 / 0.5 setup):
- Vein size ×0.5 — each ore cluster contains about half as many blocks.
- Vein count ×0.5 — about half as many veins generate per chunk.
- Large veins ×2 rarer — big rare veins (e.g. large diamond veins) appear half as often.
Both reductions stack, so by default you get roughly a quarter of the ore of vanilla (~75% less) — without breaking world generation in any way.
🪨 Affected ores
Every valuable ore, in the Overworld and the Nether — vanilla and modded:
Coal · Iron · Copper · Gold · Redstone · Lapis Lazuli · Diamond · Emerald · Nether Gold · Nether Quartz · Ancient Debris (Netherite)
Purely decorative/building blobs are left at vanilla by default (andesite, diorite, granite, tuff, gravel, dirt, clay, infested stone, magma, soul sand, blackstone) — but you can include them with one config edit.
📉 Examples (vanilla → default config)
| Ore | Veins per chunk | Vein size |
|---|---|---|
| Diamond (small) | 7 → 4 | 4 → 2 |
| Diamond (large, rare) | 1 in 9 chunks → 1 in 18 | 12 → 6 |
| Iron (mountains) | 90 → 45 | 9 → 5 |
| Gold | 4 → 2 | 9 → 5 |
| Redstone | 4 (+8 deep) → 2 (+4) | 8 → 4 |
| Coal | 30 + 20 → 15 + 10 | 17 → 9 |
| Emerald | 100 → 50 | 3 → 2 |
| Nether Quartz | 16 → 8 | 14 → 7 |
| Ancient Debris | unchanged frequency | 2 → 1 / 3 → 2 |
⚙️ Configuration
A config file is generated on first launch at config/oresreduced.json:
{
"enabled": true,
"sizeMultiplier": 0.5,
"generationChance": 0.5,
"affectModdedOres": true,
"excludedOres": [
"andesite", "diorite", "granite", "tuff", "gravel",
"dirt", "clay", "infested", "magma", "soul_sand", "blackstone"
]
}
| Option | Description |
|---|---|
enabled |
Master switch. false = vanilla generation. |
sizeMultiplier |
Multiplies ore vein size (0.01–1.0; 1.0 = vanilla). |
generationChance |
Multiplies ore vein count per chunk and rarity (0.01–1.0; 1.0 = vanilla). |
affectModdedOres |
Also reduce ores added by other mods. |
excludedOres |
Ore families left untouched (matched by feature name, e.g. andesite, gravel, or gold). |
Examples
- Hardcore (~1/16 of vanilla ore):
sizeMultiplier: 0.25,generationChance: 0.25. - Gentle (~half of vanilla ore):
0.75 / 0.75. - Smaller veins, same amount:
sizeMultiplier: 0.5,generationChance: 1.0. - Also thin out gravel/dirt: remove them from
excludedOres. - Don't touch gold: add
"gold"toexcludedOres.
Changes apply on the next server/world restart and affect newly generated chunks only. Already-generated terrain keeps its ore.
❓ What happens where an ore was removed?
Nothing strange — that spot is simply normal stone / deepslate / netherrack. Ore generation only ever replaces stone with ore, so reducing it just leaves more plain stone. Terrain shape, caves, lava, water, structures and other ores are completely unchanged. No holes, no gaps, no corruption.
🔧 Compatibility
- Minecraft: 1.21.4
- Loader: Fabric (Fabric Loader ≥ 0.16.0)
- Dependencies: none — Fabric API is not required
- Side: server-side (works in singleplayer too via the integrated server)
- Works alongside other mods; modded ores are reduced too (toggle with
affectModdedOres).
🛠️ How it works (technical)
OresReduced does not permanently overwrite any files. While the world's worldgen data
is loading, it intercepts the ore configured_feature / placed_feature JSON and rescales
size, count and rarity according to your config (via a mixin on
RegistryDataLoader). This keeps it compatible with other mods' ores and never corrupts
game data.
📦 Installation
- Install Fabric for Minecraft 1.21.4.
- Drop
oresreduced-fabric-1.21.4-1.0.0.jarinto yourmods/folder (server side). - Start once, then tweak
config/oresreduced.jsonif you like and restart.
Enjoy mining that actually feels rewarding again! ⛏️


