How to Make an RLCraft Server

RLCraft version facts

RLCraft has stayed on Minecraft 1.12.2 for years, which is why it needs the older Java 8 rather than the Java 21 that current Minecraft uses.

The official RLCraft server pack

The author publishes a ready server pack on the pack's CurseForge page, under Additional Files: RLCraft Server Pack 1.12.2 - Release v2.9.3. It contains the mods, configs, scripts, structures and a preset server.properties — but not Forge itself, which you install separately.

The pack also includes a readme with settings the author asks every server to use:

allow-flight=true
difficulty=3
max-tick-time=-1
enable-command-block=true

allow-flight stops the server kicking players for the pack's movement mechanics, max-tick-time=-1 stops a long structure generation being treated as a crash, and command blocks are needed for villagers to spawn properly in generated structures. Keep view-distance at 10, or lower it to 8 or 6 with many players.

How much RAM an RLCraft server needs

The RLCraft author only gives guidance for players' games (3 to 4 GB), not for servers, so this is our recommendation:

On Minecraft 1.12.2 most of the world runs on one CPU thread, so a fast CPU matters as much as memory — and more RAM than the pack needs does not make it smoother.

Path A: set up an RLCraft server yourself

1. Install Java 8 on the machine.
2. Install Forge 1.12.2-14.23.5.2860 with the Forge installer's Install server option, into an empty folder.
3. Add the server pack. Unzip the official server pack into the same folder, so its mods, config, scripts, structures and resources folders sit next to the Forge server.
4. Check server.properties against the author's settings above and set eula=true.
5. Start it with enough memory, for example -Xmx8G in the start command.
6. Pre-generate the world if more than about ten people will play: the readme recommends it, using the pack's Chunk Pregenerator.

Players connect to your public IP on port 25565, forwarded on your router. General modded-server steps are in how to make a modded Minecraft server.

RLCraft server hosting on HytHost

1. Pick a plan on modded Minecraft hosting.
2. Install RLCraft from the Modpacks tab in the panel: search for RLCraft and choose v2.9.3.
3. Set Java 8 in the Startup tab before the first start — RLCraft will not run on newer Java.
4. Apply the author's settings in server.properties with the file manager, then start the server and share the address.

Automatic backups are included; take a manual one before you change configs or update the pack.

How friends join

Every player needs Minecraft Java Edition with RLCraft v2.9.3 — the same version as the server. The author recommends the CurseForge app: install RLCraft there, give the game 3 to 4 GB of RAM in its settings, start it and add the server under Multiplayer. If players use OptiFine, it must be the 1.12.2 HD_U_G5 build; other OptiFine versions crash the pack.

Common RLCraft server problems

The server crashes immediately on start

Almost always the Java version. Forge for Minecraft 1.12.2 needs Java 8; newer Java versions fail at start-up.

Players are kicked for flying

Set allow-flight=true, as the pack's readme asks. Several RLCraft mechanics look like flying to the server.

"A single server tick took 60.00 seconds"

The watchdog stopped the server during a long generation. RLCraft's readme sets max-tick-time=-1 to disable it; pre-generating the world removes the cause.

The world gets slower over weeks

Explored area and villages add up. Pre-generate, keep view distance moderate, and — as the readme suggests for big, long-running servers — delete Village.dat from the world folder occasionally while the server is stopped.