Mods and Plugins on a Hosted Game Server: How They Work
By Linus Pierre · Updated November 2026
Mods and plugins are where a game server gets interesting, and where most join errors come from. This guide explains server-side and client-side mods, how loaders work, where mods come from and a safe routine for adding them, then links to the mod guide for your game.
Mods change the game and often have to be on the server and on every player’s PC. Plugins add server features and often run only on the server. A loader such as BepInEx, Oxide or Fabric starts them. On a rented server you install mods with the panel’s installer or by uploading files, restart, and check the log. Back up first and add one mod at a time.
- Server plugins: players install nothing.
- Content mods: server and players on the same versions.
- After updates: update the loader first.
Mods, plugins, modpacks and loaders: what the words mean
“Mods” is used for almost anything that changes a game, but on a server it helps to split it into four things. Most problems with a modded server come from mixing them up.
1Mods
A mod changes the game itself: new items, creatures, maps, rules or mechanics. Because it changes what the game knows about, a mod often has to be on the server and on every player’s PC at the same version.
2Plugins
A plugin adds features to the server, such as admin tools, kits, economy or permissions, without changing the game files players have. Many plugins run only on the server, so players join with the normal game. On a Rust server, for example, plugins run on the server through Oxide or Carbon and players download nothing.
3Loaders and frameworks
A loader is the layer that starts mods or plugins in the first place. Examples from our game guides include Fabric, Forge and NeoForge for Minecraft, BepInEx for Valheim, UE4SS for Palworld, Oxide or Carbon for Rust, Metamod:Source and SourceMod for Left 4 Dead 2, and tModLoader for Terraria. The loader goes on first, then the mods.
4Modpacks
A modpack is a set of mods, settings and versions picked to work together. The server and every player use the same pack at the same version, which is far easier than matching forty mods one by one.
Server-side, client-side or both
The first question for any mod is where it has to run. Get this right and most “my friends cannot join” problems never happen.
The awkward row is the second one. In games like DayZ and Arma 3, the server and every player need the same mods at the same versions, so one player with an old copy cannot join. In others, such as Project Zomboid, ARK or Factorio, the game downloads the server’s mods for players when they connect, so they only need the right game version. Vintage Story has done this since version 1.16, and Abiotic Factor does it for official mod.io mods.
Some games mix both. Minecraft plugins are server-only, but content mods that add blocks or items have to be on every player’s game too. Valheim mods can be client-only, server-only or shared, and shared mods usually need the same version on the server and on each player’s PC.
How mods actually load on a server
A modded server is a stack. The game server starts, a loader starts on top of it, and the loader then loads each mod. Some games, such as Project Zomboid, Arma 3 or Factorio, load mods themselves from a list or a folder, so there is no separate loader, but the idea is the same: the server only runs what it is told to load at startup.
- 1 · Game serverThe dedicated server, on the exact game version
- 2 · Loader or frameworkStarts the mods, built for that game version
- 3 · Mods and pluginsBuilt for that loader and game version
- 4 · Your settingsConfig files the mods create on first start
That is why the same few things go wrong in every game: a mod in the wrong folder, a loader built for a different game version, a missing dependency, or a mod list that does not match the files. The fix is almost always in the server log, which lists what actually loaded.
Where mods come from
Each game has its own home for mods, and that decides how you install them on a server.
The mod pages for many Steam games. The server is given Workshop IDs and downloads the files, or you copy them across.
Large mod sites. Minecraft modpacks come from both, and ARK: Survival Ascended uses CurseForge instead of the Workshop.
Used for official mods in some games. The server is given mod IDs and fetches them itself.
A community mod site with its own mod manager. Our Valheim guide uses r2modman or Thunderstore Mod Manager so the whole group shares one mod profile.
Some games have their own mod site, sometimes with an in-game browser or a server command that installs mods by name.
Server plugins usually come from the framework’s own community, separate from the game’s mod pages.
The source also explains a classic mistake. Subscribing to a Workshop mod on your own PC does nothing for a dedicated server, which is a separate program. Conan Exiles and Palworld are good examples: the server only loads the files that are actually in its own mod folder.
Installing mods on a hosted server: one-click or by hand
On a rented server you have two ways to add mods, and most people use both.
1One-click installers in the panel
Many hosts add a mod, plugin or modpack installer to their control panel. You pick the mod, the panel downloads it and sets up the files. It is the quickest route, but check that your game and your mods are covered before you rely on it.
2Uploading files yourself
Anything the installer does not cover goes in by hand: upload the files with the file manager or SFTP, put them in the folder the game expects, and add them to the mod list or startup line. Full file access is what makes this possible, so check a host gives it to you.
3Mod lists and startup settings
Most games need to be told which mods to load: a list of Workshop or mod IDs in a config file, a modlist file, or a launch option such as Arma 3’s -mod line. Good panels expose these as fields, but you should still be able to edit the file underneath.
4Restarts
Mods are read when the server starts, so a restart is part of every change. Many games also update Workshop mods on restart, which is useful, but means a restart can quietly bring in a new mod version.
A safe routine for adding mods
The same order works in every game. It turns a broken server into a five-minute fix instead of a lost world.
- ProtectBack up firstCopy the world and configs before every change. Removing a mod later can strip its content from the save.
- CheckMatch the versionsCheck the mod supports your game version and loader, and note any required mods it depends on.
- AddOne mod at a timeAdd the mod and its dependencies, not ten mods at once, so you know which one caused a problem.
- RestartRestart the serverMods load at startup. Stop the server before editing files where the game asks you to.
- ReadRead the logLook for the line that says the mod loaded, and for the first error after it.
- TestJoin and testJoin with a normal player account, not only as admin, and check the mod works before adding the next.
Our game server backups guide explains how to take and restore a backup properly. Treat mods with the same care as any other code you run: download them only from the game’s usual mod pages, and see game server security for the other basics.
Why mods break after game updates
A modded server that worked yesterday and fails today has usually been updated. These are the patterns our game guides see again and again.
| What happened | What you see | What to do |
|---|---|---|
| Players updated a Workshop mod before the server did | Version mismatch or kick when joining, as in Arma 3 and Conan Exiles | Restart or update the server so it fetches the same mod version |
| The game updated but the loader did not | Mods stop loading, or the server starts as if it were unmodded | Update the loader first; on Rust, Oxide has to be reinstalled after each server update |
| A mod has not been updated for the new game version | Server crash at startup, or one mod missing from the log | Remove or disable that mod until the author updates it, then restore your backup if needed |
| The game moved to a new major version | Old mods refuse to load, as with Factorio 1.1 mods on a 2.0 server | Use mods built for the new version, or pin the server to the old one |
| Server and players are on different builds | Players cannot join at all | Keep the server, the loader, the mods and every player on the same version |
If you run a big modpack, it is worth pinning the server to the game version the pack supports rather than always updating straight away. Our 7 Days to Die overhaul modpack guide shows how that works in practice.
Mod guides for each game
The steps above apply everywhere, but folders, files and mod lists differ between games. This table sums up what each of our mod guides says, with a link to the full steps and to our host comparison for that game.
| Game | How mods load | What players need | Full guide | Compare hosts |
|---|---|---|---|---|
| 7 Days to Die | XML modlets and DLL mods in the Mods folder | XML-only modlets usually not; mods with assets or DLLs usually yes | Mod guide | Best hosts |
| Abiotic Factor | Official mod.io mods, set by ID | Accept a download prompt when joining | Mod guide | Best hosts |
| ARK: Survival Ascended | CurseForge mod IDs in the server settings | Downloaded automatically when joining | Mod guide | Best hosts |
| ARK: Survival Evolved | Steam Workshop mods | Downloaded automatically when joining | Mod guide | Best hosts |
| Arma 3 | Workshop @folders, keys and the -mod line | The same mods at the same versions | Mod guide | Best hosts |
| Conan Exiles | .pak files and modlist.txt | The same mods, in the same order | Mod guide | Best hosts |
| DayZ | Workshop @folders, keys and the -mod line | The same mods at the same versions | Mod guide | Best hosts |
| Don’t Starve Together | Workshop mods, set up in two files per shard | Server mods are downloaded when joining | Mod guide | Best hosts |
| Euro Truck Simulator 2 | A mod list exported from a player’s profile | The same required mods, in the same order | Mod guide | Best hosts |
| Factorio | Mod .zip files in the mods folder | Accept the mod sync prompt when joining | Mod guide | Best hosts |
| Garry’s Mod | Workshop collection, plus downloads for content | Content is sent to players if the server is set up for it | Mod guide | Best hosts |
| Hytale | Plugin .jar and asset pack .zip files in mods/ | Nothing to install | Mod guide | Best hosts |
| Left 4 Dead 2 | Metamod:Source, then SourceMod, then plugins | Check each plugin’s page | Mod guide | Best hosts |
| Minecraft | A loader (Fabric, Forge, NeoForge) and mods, or plugins | Content mods yes, plugins no | Mod guide | Best hosts |
| Palworld | UE4SS on a Windows server | Only for mods marked for both sides | Mod guide | Best hosts |
| Project Zomboid | Workshop IDs, mod IDs and map folders in the server settings | Usually downloaded when joining | Mod guide | Best hosts |
| RimWorld | RimWorld Together checks each player’s mod list | Every player runs the mods | Mod guide | Best hosts |
| Rust | Plugins through Oxide or Carbon | Nothing to install | Mod guide | Best hosts |
| Terraria | tModLoader, a separate server program | tModLoader and the same mods | Mod guide | Best hosts |
| Unturned | Workshop content and server plugins | Workshop content is downloaded when joining; plugins need nothing | Mod guide | Best hosts |
| Valheim | BepInEx and plugins | Shared mods at the same versions | Mod guide | Best hosts |
| Vintage Story | Mods from the VS ModDB, often with one command | Downloaded automatically when joining | Mod guide | Best hosts |
Running Terraria plugins rather than content mods? See our TShock setup guide. For a big 7 Days to Die pack, use the overhaul modpack guide. If your game is not listed, find it in the game hosting hub.
Do mods need a bigger server?
Often, yes. Content mods add items, creatures and world data, and every extra system uses memory and processor time. A big modpack can need far more memory than the same game unmodded, while a handful of small admin plugins barely changes anything.
Size from the game’s own figures, then add headroom for your mods. Our guide to how much RAM and CPU a game server needs links to the figures for each game, and slots vs RAM pricing explains why a plan sold by player slots can suit a modded server differently from one sold by memory. If a modded server starts to stutter, why is my game server lagging? helps you find out whether a mod is the cause.
Some mods also depend on the server’s operating system. Palworld’s UE4SS mods, for example, need a Windows server. Our guide to Linux vs Windows game servers explains when that matters.
Planning a modded server?
These are the top three hosts in our UK ranking, in ranking order. According to our reviews, all three have mod tools in the panel: Indifferent Broccoli’s own panel includes mods, LOW.MS has one-click mods in its Nexus panel, and Host Havoc has mod and modpack installers.
What to check before you rent a modded server
- Your game: a mod, plugin or modpack installer for the game you play.
- Files: full file access in the browser and SFTP, for mods the installer does not cover.
- Startup: fields or files for the mod list and launch options.
- Backups: backups you can take and restore yourself before every change.
- Memory: enough headroom for your mods, not just the unmodded game.
- Operating system: a Windows server if your mods need one, as UE4SS mods for Palworld do.
- Versions: a way to pick or pin the game version your modpack needs.
Mods and plugins on a game server: common questions
What is the difference between a mod and a plugin?
A mod changes the game itself, such as new items, creatures or maps, so it often has to be on the server and on every player’s PC. A plugin adds features to the server, such as admin tools or kits, and many plugins run only on the server, so players join with the normal game.
Do my friends need to install mods to join my server?
It depends on the game and the mod. Server plugins need nothing from players. In games such as ARK, Project Zomboid and Factorio, the game downloads the server’s mods when players join. In DayZ, Arma 3 and Conan Exiles, every player needs the same mods at the same versions.
Can I add mods to a rented game server?
Yes, on most hosts. Many control panels have one-click installers for mods, plugins or modpacks, and with full file access you can upload any other mod yourself through the file manager or SFTP.
Why did my mods stop working after a game update?
Usually because the server, the loader, the mods or the players are no longer on matching versions. Update the server and the loader first, then remove any mod that has not been updated for the new game version.
Is it safe to remove a mod from a server?
Not always. Removing a mod can delete its items, buildings or creatures from the world, and some saves will not load without it. Back up the world first, and check the mod’s page for how to remove it safely.
Do mods need more RAM?
Often. Content mods and big modpacks can need much more memory than the unmodded game, while a few small plugins make little difference. Start from the game’s own figures and add headroom for your mods.
