Playing Biomes O' Plenty on Minecraft 1.12.2
How the legacy 1.12.2 line of Biomes O' Plenty differs from modern versions: Forge only, Java 8, the BIOMESOP world type and server settings.
Minecraft 1.12.2 is one of the most heavily modded versions ever released, and many classic modpacks were built on it. Biomes O' Plenty was a staple of that era, so the 1.12.2 search term is still common. Setting it up works differently from modern versions, and knowing those differences saves a lot of confusion.
Why people still play 1.12.2
Some players want a specific older modpack. Others prefer the 1.12.2 feature set or have long-running worlds they do not want to migrate. Whatever the reason, treat 1.12.2 as its own separate setup rather than an "older copy" of today's mod.
What is different on old versions
| Topic | 1.12.2 line | 1.18 and newer |
|---|---|---|
| Loader | Forge | Forge, NeoForge or Fabric depending on version |
| Biome injection | Biomes O' Plenty world type | TerraBlender, no special world type |
| Server setting | level-type=BIOMESOP | No server.properties change needed |
| Java runtime | Java 8 | Java 17 or newer, depending on version |
The biggest practical change is the world type. On 1.12.2 the new biomes only appear in a world created with the Biomes O' Plenty world type. A world made with the default type stays vanilla, even with the mod installed.
Setting up a 1.12.2 client
- Install Forge for 1.12.2 and run its profile once.
- Make sure the profile runs on Java 8. Newer Java versions commonly break 1.12.2 Forge.
- Put the 1.12.2 build of Biomes O' Plenty in the
modsfolder. - Create a new world, open "More World Options" and cycle the world type until the Biomes O' Plenty option appears.
Do not add TerraBlender or GlitchCore to a 1.12.2 setup. Those libraries belong to modern versions and are not used by the legacy line.
Running a 1.12.2 server
For a dedicated server, the project notes say the level-type in server.properties must be set to BIOMESOP on 1.12.2 and below. If the line is missing, you can add it manually. The setting only affects newly generated worlds, so either start fresh or delete the old world folder after making a backup. Every player connecting to the server also needs the same mod version on their client.
Setting expectations
The 1.12.2 line reflects the mod as it was at the time. Biomes, blocks and names have changed since then, so modern guides and biome lists will not always match what you see. If you are starting a brand-new world and do not need an older pack, a modern version such as the 1.20.1 line or newer gives you the current content and the TerraBlender-based generation. Whichever version you pick, the biome-finding guide explains how to track down specific biomes.