Valheim mods on your server: BepInEx without the hassle
Valheim is a beautiful game even bare, but anyone with hundreds of hours in it starts dreaming: slightly smoother building, a shared map, tougher bosses. That is what mods are for, and virtually all Valheim mods run on the same foundation: BepInEx. The good news: setting up a modded server is less scary than it sounds. The honest news: there are a few rules you need to know, or you will be staring at a server that refuses to start after the next game update. Both are covered in this guide.
How modding works in Valheim
BepInEx is a mod loader: a layer that loads along when the server starts and then injects plugins into the game. The mods themselves are .dll files you put in the folder BepInEx/plugins; their settings automatically appear as .cfg files in BepInEx/config after the first start. So the order is always: first install BepInEx on the server, only then add mods. You put the files on the server via your panel's file manager or via SFTP. Mods are found on the well-known mod sites; grab the server variant of a mod where available, and note down for every mod where you got it. At the next update you will be glad you did.
Whether it works, you see immediately at startup: BepInEx neatly writes out in its log file which plugins loaded and which threw an error. Make it a habit to glance at that log after every change. A mod that silently fails to load, you otherwise only discover when a player wonders why his new build pieces are missing.
Server-side or client-side: the key distinction
The most important question for every Valheim mod: who has to install it? There are three flavours:
- Only the server. Mods that change server logic, such as spawn behaviour or world settings. Players do not have to do anything and only notice the effect.
- Server and all players. Mods that add items, recipes, build pieces or enemies. Everyone has to run the same mod, often with the same configuration too. If not, you get desync, vanished items or players who cannot join the server.
- Only the player. Pure interface and graphics mods. Those are independent of your server and are the player's own choice.
The mod page almost always states which category a mod falls into. Publish your full mod list in your Discord, including which mods players need themselves. Even better: bundle the client mods into a modpack, so everyone is guaranteed to run the same set.
Popular directions
Without trying to be a catalogue (version numbers age faster than blogs), you see roughly three popular flavours on Valheim servers:
- Quality of life. Sorting helpers, bigger stacks, map sharing between players: the irritations gone, the game intact. The most popular starting point for most groups.
- Building. Extra build pieces, smoother placement, even without build costs for creative servers. For groups that turn Valheim primarily into a building game.
- Difficulty and progression. Tougher enemies, richer loot and RPG-like progression for vikings who have beaten the bosses one time too many.
Start small. Two or three mods that do exactly what your group wants bring more joy than thirty mods nobody remembers the purpose of. And every mod you add is one more that will need updating later. Also check first whether you need a mod at all: for tweaking things like drops, portals and raids, Valheim nowadays has built-in world modifiers, entirely without risk.
When a game update arrives
This is the least fun part of a modded server, so let us be honest about it: after a Valheim update, everything can temporarily be broken. Mods hook deep into the game's code, and when that code changes, BepInEx and every individual mod have to be updated by their makers. That can take days, sometimes longer. What you can do: do not blindly update or restart your server on the day of a big patch (turn off automatic updates if your panel allows it), announce to your players that it may take a while, and afterwards update your mods one by one so you can see which one still causes problems. If an essential mod does not work yet, waiting a little is usually wiser than forcing your way through. Do not forget the client side either: your players have to update their own mods at the same moment, or you will still end up facing each other with different versions. One message in Discord with the updated mod list saves an evening of troubleshooting.
Back to vanilla
If you want to get rid of all mods, or have to go back temporarily because an update broke everything, that is possible. Valheim's world files (a .db and a .fwl file per world in the folder worlds_local) remain readable without mods. Remove the BepInEx files from the server or reinstall the server via your panel, put your world files back and the server runs vanilla again. But mind the fine print: everything that came from a mod disappears or throws errors. Modded build pieces dissolve into nothing and modded items vanish from chests. So always test the switch first with a copy of your world before making it final.
Backups: before every mod change
The pattern in this whole story: mods make your server more interesting and more fragile at the same time. The answer to that is simple and free: make a backup before every installation, update or removal of a mod. If something goes wrong, you restore it and no harm done; without a backup, one broken mod can damage your world. In the panel, making a backup is a matter of a few clicks, and with a schedule you automate it. By the way, you rent a Valheim server at MC-Node from € 3.00 per month, on our own hardware with NVMe storage in the Previder data center in Hengelo, with DDoS protection and cancellable monthly; check the plans in the Valheim store. But wherever you run: first that backup, then the mod.