How to play with friends on mods? A practical guide

Playing modded together is probably the most enjoyable side of Minecraft. New dimensions, machines, magic, dozens of mobs you will never meet in the plain game. The catch is that getting several people onto the same pack takes a few steps nobody touches during a regular survival run. In this guide we walk through all of it calmly: from agreeing on a shared modpack, through picking how you connect, all the way to setting up a server the whole crew can join.

Mods work differently than plugins

Let us start with the thing that confuses most people. A plugin lives only on the server side, and a player joins with the plain game without changing anything on their end. Mods are the opposite. A mod changes the game itself, so it has to be present on everyone who wants to play. If your pack has new ores and machines and your friend's does not, you simply will not connect to each other. So the first rule of playing modded together is this: everyone runs an identical set of mods in an identical version.

First a shared modpack and one loader

Before anyone launches anything, agree on two things: which pack you play and on which loader. A loader is the program that lets the game read mods at all. You cannot skip it, and the loaders do not talk to one another. A mod written for one will not run on another, so the whole crew has to stick to the same one.

A launcher does most of the work for you

Dropping mods into a folder by hand sounds scary, and it really is easy to slip up there. Luckily almost nobody does it that way anymore. Ready-made modpacks are downloaded through launchers that pick matching versions of the mods and the loader for you. That way each of you installs exactly the same set with one click.

• CurseForge and Modrinth are the two biggest libraries of ready-made packs. All you need is for everyone to download the same pack from the same place.
• Prism Launcher and ATLauncher are handy programs for managing several packs at once, with clear control over the assigned memory.
• If you are building your own pack from scratch, appoint one person to assemble the set and send it to the rest. Otherwise you end up with everyone holding a slightly different list of mods.

A server is the most convenient way to connect

You share a pack, now it is time to gather the crew in one world. For a single evening you can open the world to a local network or run a host on one player's computer. These are stopgaps, and for regular play they start to chafe fast. The world only lives while the host sits in the game, so the moment they leave, the rest are locked out. On top of that the whole modpack rests on a single home connection and a single processor, which you feel right away with mods.

That is why a separate server works best for steady group play. It runs no matter who is online, it has its own resources just for your pack, and it gives you a ready address you hand to your friends once. The contrast shows it best:

How much memory you need with mods

This is where modded differs sharply from the plain game. Every mod adds something to memory, and big packs can hold several hundred of them. So the values that are plenty for a regular survival turn out to be far too small for a modpack. Treat the table below as a sensible starting point for group play:

Setting up a modpack server step by step

Let us assume you go with a separate server, the option that limits you the least. The whole trick is getting the same pack onto the server that you have in your game. On hosting that comes down to a few clicks in a panel. At MineHost it looks like this:

1. 1

   Match the package to the pack size

   Use the memory table above and for mods pick a Premium package with dedicated resources, because on shared ones a modpack tends to be unstable. It is also better to take a little headroom, because a heavy pack grows faster than you expect. You can always switch to a bigger package later without losing your world.
2. 2

   Install the modpack on the server side

   In the panel you pick a ready-made modpack from a list or upload your own set. The key is that the loader and version match what you have in your game.
3. 3

   Start the server for the first time

   The first launch generates the world and the pack config files. It is also when the server accepts the licence in the eula.txt file.
4. 4

   Check that the versions line up

   Before you invite the whole crew, join yourself and make sure your game connects without kicks. If it reports a missing mod, you have a mismatch between the game and the server.
5. 5

   Hand out the address and the pack

   You get a ready address or a free subdomain. Send the crew that address along with a link to the exact pack the server runs.
6. 6

   Set up backups right from the start

   Modpacks can be temperamental, and one incompatible mod can make a mess. Turn on backups before anything goes wrong, not after.

Server mods versus player-only mods

Not every mod has to go on the server, and this is where many people get lost. Part of a pack handles the world and mechanics, so it is needed on both sides. But there are also mods that only change what a single player sees, and those you do not have to put on the server at all.

• Mods that add blocks, mobs, dimensions, ores or machines must be on both sides. Without them the server and the player speak different languages.
• Mods that improve performance and looks, like Sodium or minimap mods, run only on the player. The server does not even need to know about them.
• If you are not sure which group a given mod belongs to, check its description. Authors usually state plainly whether it is a client mod, a server mod, or required on both sides.

Common problems and how to avoid them

• Each player downloads the pack from a different place, so the mod lists differ slightly. Agree on a single source.
• One person updated the pack, the rest did not. Update everyone at the same moment.
• Too little memory assigned in the launcher, so the game crashes while loading heavier biomes. Check your own memory settings.
• Mixing loaders, meaning someone has Fabric and someone has Forge. That will never connect, so pick one.
• No backup before adding a new mod. A backup is made before the change, not after the crash.
• Loading client-side mods onto the server and being surprised by crashes. Only the mods the server actually needs go on the server.

Quick FAQ

Do my friends need exactly the same mods as I do?

Yes, for mods that change gameplay there are no exceptions here. The whole crew plays on an identical set and an identical version. The exception is purely cosmetic or performance mods, which everyone can run their own way.

Can I play modded without setting up a server?

You can, for instance by opening the world to a local network. The catch is that such a game only lives while the host sits in the game, and once they leave the world is unavailable for the rest. For regular play a separate server is simply more convenient.

Can I change the modpack on the server while playing?

You can, but treat it carefully. Swapping the pack on a live world can lose blocks and items from removed mods. Always make a backup first, and test bigger changes on a separate world.