Running a modpack server with friends: ATM10, Cobblemon, Create

Playing a modpack together is one of the best things you can do with your own Minecraft server. Think of a big pack like All the Mods 10, Pokémon adventures with Cobblemon, or building factories with Create. It works best when you get three things right: enough memory, the pack installed properly on your server, and exactly the same version for all your friends. This article shows you how.

First: which modpack?

A modpack is a fixed collection of mods with settings that are tuned to work together. Three popular examples:

• All the Mods 10 (ATM10) is a big pack on NeoForge for Minecraft 1.21.1. On CurseForge its makers mention around 500 mods, covering tech, magic, exploration and automation.
• Cobblemon is a Pokémon mod for Fabric and NeoForge. On Modrinth, Minecraft 1.21.1 is the newest supported version. Small packs built around it run fine on an ordinary server.
• Create is all about machines, cogs and factories. It runs on Forge and NeoForge and features in lots of packs.

Notice something? Many popular packs still run on Minecraft 1.21.1 rather than 26.x. That’s normal: pack makers wait until their mods have been updated. So choose the Minecraft version that belongs to your pack, not the newest one.

How much memory, and which line?

Mods need far more memory than a plain Paper server. For larger packs, count on 8 GB or more, and more still for packs with hundreds of mods. For mods, our server size calculator uses a 4 GB base, plus 0.2 GB per player and 0.04 GB per mod. Also check what the pack’s makers recommend.

With big packs the processor matters as well. Minecraft simulates the world largely on one core, and hundreds of mods keep that core very busy. Premium runs on faster processors and gets more processor time per plan, which makes it the more comfortable choice for ATM10 with a group of friends. A small Cobblemon pack usually runs fine on Standard.

Installing through the game panel

1. Make a backup, or start with an empty server if you’re starting fresh.
2. Open Modpacks in the game panel, under the Minecraft heading.
3. Choose a source. You can search for packs on Modrinth, CurseForge, Feed The Beast, ATLauncher or Technic.
4. Find your pack and choose Install. Then select the pack version.
5. Decide whether to wipe first. The Delete files option removes all your server files before installing the pack, your world included. Handy for a clean start, but only if you have a backup.
6. Start your server. The first start takes longer, because every mod is loaded and the world is generated.

When it starts, your server picks the Java version that matches your pack’s Minecraft version by itself, for example Java 21 for 1.21.1, so there’s nothing for you to do there. The panel also rightly warns that updating a modpack can corrupt your world, so always make a backup first.

Your friends: exactly the same version

Everyone who plays installs the same pack, in the same version, on their own computer. The easiest way is a launcher that supports modpacks, such as the CurseForge app, the Modrinth App, Prism Launcher, ATLauncher or the FTB App. If the versions don’t match, players get a message about missing or mismatched mods when they connect.

Agree on who updates the pack and when. Update the server first, after making a backup, and then have everyone update their launcher.

How your friends join, step by step

1. Install the launcher that carries the pack, for example the CurseForge app or the Modrinth App.
2. Find the pack and install exactly the version running on the server.
3. Give the pack enough memory; most launchers have a setting for this.
4. Start the pack, choose Multiplayer and add the server using the address from the game panel.

Building your own pack

Prefer your own selection of mods? Choose a Fabric or NeoForge server and the Minecraft version you want under Versions. Mods go into the mods folder, through the file manager, SFTP or the Mods section of the panel. Only mods the server needs belong there. Mods that only run for the player, such as a minimap or shaders, stay on the players’ computers.

Tips for a smooth modpack server

• Lower view-distance a little, for example to 8. It saves a lot of memory.
• Schedule a daily restart and an automatic backup under Schedules.
• Keep track of which pack version you’re running, so everyone knows what to install.
• Turn on the whitelist, so only your own group gets onto the server.
• Agree on a fixed day for updates, so nobody suddenly can’t join halfway through an evening.
• Tell your friends how much memory to give the pack in their launcher; big packs need more than the default.