RLCraft at a glance
| Minecraft version | 1.12.2 |
|---|---|
| Mod loader | Forge (the classic 1.12.2 series, not NeoForge) |
| Java | Java 8 - the server does not start under Java 17 or 21 |
| Concept | hardcore survival with thirst, temperature, an injury system and dragons |
| Source | CurseForge - installable with a click in the panel |
| Defining mods | Ice and Fire, Lycanites Mobs, SpartanWeaponry, First Aid, Toughness |
| World generator | level-type=BIOMESOP - upper case, set before the world is first generated |
| Special feature | CPU-heavy rather than mod-heavy - many active mobs per chunk |
| Recommended plan | plan L - 6 GB are commonly quoted as the minimum allocation |
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RLCraft server hosting
Prepaid from €2.99 / month, unlimited slots, no minimum term. The right plan is listed in the RAM table below.
Plans & pricesWhy RLCraft is technically out of line
Almost all current modpacks run on Minecraft 1.20 or 1.21 and require Java 17 or 21. Not RLCraft: the pack is built on 1.12.2 and has stayed there, because the defining mods - above all Ice and Fire and Lycanites Mobs - have their familiar scope in this version. A port to newer versions would change how the game feels.
For the server, this means: you have to actively set the Java version down. Forge for 1.12.2 is sensitive to Java runtimes that are too new and as a rule does not start at all under Java 17 or 21. In the web interface, you will find the setting under Startup in the Docker Image field - choose Java 8 there, stop the server, start it again. The background is explained in Change the Java version.
A second point strikes people switching over: for 1.12.2 packs, the panel does not offer an automatic version change to a newer Minecraft version that RLCraft would survive. Whoever plays RLCraft stays on 1.12.2 - that is not a shortcoming but part of the package.
What puts load on the server with RLCraft
RLCraft is not an automation pack. There are no ME networks and no factory chains burning ticks in the background. The load comes from elsewhere: mobs. Lycanites sets its own spawn rules, Ice and Fire scatters dragons and their caves across the world, and during events such as a Lycanites invasion, dozens of entities suddenly stand around the players at once.
This shifts the picture compared to kitchen-sink packs such as ATM9: RLCraft needs less memory, but more continuous computing power per core. That is exactly what our hardware is designed for - modded Minecraft essentially handles the world in one thread, and single-core performance decides the TPS.
The practical consequence: more RAM rarely solves stutter here. If TPS drop, look at the number of active entities in loaded chunks rather than the memory display. How to measure this is described in Lag and TPS.
World generation and server.properties
RLCraft expects its own world generator - if the world is generated with the default values, the typical biomes and structures are missing, and the pack simply feels wrong. Responsible for this is Biomes O' Plenty, and on Minecraft 1.12.2, the corresponding value is called BIOMESOP. Both lines belong in server.properties:
level-type=BIOMESOP
generator-settings=BIOMESOPThe spelling must be followed exactly - the value is expected in upper case and has no effect otherwise. Anyone coming from a newer Minecraft version trips up here: from 1.15, the same generator is called biomesoplenty in lower case, which is wrong for RLCraft on 1.12.2. In addition, the mod expects the option in config/biomesoplenty/terraingen.cfg to add its biomes to the default world.
The order matters: the entry must be in place before the world is generated for the first time. Once the world has been created with the wrong generator, only deleting and regenerating helps - a later change only affects newly generated chunks and leaves visible edges in the terrain. What each line of the file does is explained in server.properties.
Which plan for RLCraft?
The thresholds below apply to this pack - a light Vanilla+ pack and a kitchen-sink pack with a hundred running machines behave completely differently. You can upgrade at any time without losing data and only pay the difference.
| Group | Plan | RAM | Price | Why | Order |
|---|---|---|---|---|---|
| Solo or two players | Plan M | 4 GB | €5.99 / month | Runs, but with 4 GB is below the 6 GB commonly quoted as the minimum for RLCraft. | Order M |
| 3-10 players | Plan L | 8 GB | €11.99 / month | The normal case. 8 GB absorb mob events and several areas being explored at the same time. | Order L |
| Public server | Plan XL | 16 GB | €21.99 / month | If players are permanently spread across the whole map, many chunks are active at the same time. | Order XL |
| When it stutters | Plan L | 8 GB | €11.99 / month | More RAM rarely helps here - the load from entities is on the CPU. | Order L |
The memory is taken proportionally from the plan via -XX:MaxRAMPercentage - you don't need to maintain a fixed -Xmx. The basics are covered in the RAM guide.
Setting up RLCraft on the server
- Stop the server in the web interface.
- In the guided setup, choose Forge and search for RLCraft via the CurseForge installer.
- Under Startup, set the Docker image to Java 8. That is the decisive step - with Java 17 or 21, RLCraft does not start.
- Enter
level-type=BIOMESOPandgenerator-settings=BIOMESOPinserver.properties- in exactly this spelling and before the world is generated for the first time. - Start the server and wait in the console for
Done. - Fellow players install the same RLCraft version via CurseForge and connect via IP and port.
Common pitfalls with RLCraft
Server does not start, log ends abruptly
Cause: The server runs on a Java version that is too new. Forge for 1.12.2 cannot cope with Java 17 or 21.
Fix: Under Startup, switch the Docker image to Java 8 and restart. More startup errors in Server does not start.
The world looks like vanilla, no RLCraft biomes
Cause: The world was generated with the default world generator because level-type was not yet set to BIOMESOP on the first start - or was in the wrong spelling, such as biomesoplenty from a newer Minecraft version.
Fix: Enter both values in upper case, delete the world folder and let it regenerate. A later change does not repair chunks that have already been generated.
Massive stutter during mob events
Cause: Lycanites invasions and dragon caves put many entities into loaded chunks at the same time.
Fix: Lower the spawn rates in the Lycanites configs and keep view-distance moderate. More RAM usually does not help here - the load is on the CPU.
Players cannot get onto the server
Cause: Client and server run different RLCraft versions; the pack checks the mod list when connecting.
Fix: Bring all fellow players to the same pack version. When updating, always the server first, then the clients.