Valheim Modding on OpenMods

A Viking survival game built on a moddable Unity stack

Valheim (2021) is Iron Gate Studio's Viking survival game, released into Early Access and quickly modded thanks to a familiar Unity Mono runtime. The community converged on BepInEx as the standard loader within months of launch, and the Thunderstore mod hub became the de-facto distribution platform, even Iron Gate links to it from official channels.

Valheim modding has the unusual property of being well-tolerated by the developers but officially unsupported. There's no Workshop integration, no in-game mod browser; everything happens through the BepInEx + Thunderstore stack the community built.

The toolchain

• BepInEx: the Unity Mono loader, version 5.x for Valheim specifically.
• r2modman (Thunderstore Mod Manager): community mod manager that installs Valheim mods from Thunderstore directly. The standard tool.
• Thunderstore.io: the mod hub. Valheim's mods are organised in its own community there.
• Jotunn (the Valheim Library): modding framework built on BepInEx, used by most content mods as a foundation.
• HookGenPatcher: a community patcher that enables Harmony hooks against Valheim's update cycle.

What you'll find on OpenMods

Most Valheim mods live on Thunderstore, with GitHub as the source repository for many of the larger ones. OpenMods catalogues GitHub-published Valheim mods, which are typically the technically-larger frameworks rather than small content packs.

Practical notes

• Use r2modman, not manual BepInEx install. r2modman handles BepInEx setup, profile management (one mod set for a server, another for solo play), and automatic dependency resolution. Manual installs are possible but unnecessarily fragile.
• Multiplayer requires server + client mod parity. Both the host and all clients need identical mods at identical versions. Thunderstore profiles can be shared via a code, which is how most modded-server communities coordinate.
• Major patches break things temporarily. Iron Gate has shipped Hearth & Home, Mistlands, Ashlands, and similar updates that broke significant portions of the mod catalogue. Most popular mods are updated within a week.
• Vanilla and modded saves are mostly cross-compatible. Removing a mod that added content (new biomes, new items) can leave dangling references, but the world doesn't usually corrupt, items just vanish.