Valheim mods on a dedicated server: which ones need the server, and which are client-only

When I started modding our Valheim server, the most important question wasn’t which mods. It was who needs to install them. Get it wrong and half your friends can’t connect.

Three kinds of mods

Kind	Who installs it	Vanilla players can join?	Examples
Server-only	the server	✅ yes	Better Networking (send-rate part)
Client-only	whoever wants it	✅ yes	quick-stacking, map pins, recipe browser, planting helpers
Everyone (server + all clients, same version)	everybody	❌ no	Multi User Chest, most mods that add items or change game rules

The third kind usually enforces a version check: if you don’t have the exact same mod and version as the server, you get disconnected. That’s what makes “everyone” mods a group decision.

How to tell which kind a mod is

1. Read the mod page. Good authors say it directly: “client-side only”, or “must be installed on the server and all clients”.
2. Does it add content? New items, creatures or building pieces need everyone.
3. Does it change shared rules? Stack sizes, carry weight or crafting from chests usually need everyone (or a config-sync library).
4. Does it only change your UI or inputs? Usually client-only.

A real example: quick-stacking into chests

The popular Quick Stack – Store – Sort – Trash – Restock mod is client-only. Quick-stacking into the chest you have open always works. Stacking into all nearby chests in multiplayer is off by default, though, because without the “everyone” mod Multi User Chest, two players touching the same chest at the same moment can lose or duplicate items.

The options:

• Everyone installs Multi User Chest (server + clients) → safe, but vanilla players are locked out.
• Only you enable AllowAreaStackingInMultiplayerWithoutMUC → vanilla friends can still join. It’s “almost always safe”, as the mod’s own description puts it. Just avoid quick-stacking while someone else is using those chests.

Since I’m the only one in our group who mods, I chose the second option.

Watch for overlapping mods

Two mods doing the same job fight each other. Things I ran into:

• Two planting mods (PlantEasily and MassFarming): pick one. PlantEasily’s page lists MassFarming as incompatible.
• Two chest sorting/stacking mods: the same thing, pick one.
• Hotkey clashes: a gear-slot mod bound Z/X/C/V and unbound Valheim’s own sit/walk/auto-pickup keys. Check every new mod’s keybinds in the config editor.

Achievements

Valheim doesn’t disable Steam achievements for mods, and server mods can’t affect them at all. Cheat commands (devcommands) are a separate thing.

Tools

• r2modman or the Thunderstore Mod Manager for your PC. Search by author name if a mod’s title has special characters. Always launch with the Modded button.
• On a Docker server (setup), set BEPINEX=true and put DLLs in config/bepinex/plugins.