Valheim World Modifiers Guide for Solo and Dedicated Servers

World modifiers change the rules of a Valheim world. They can adjust difficulty, resource availability, death penalties, raids, portals, and several optional play styles without requiring a mod.

For a shared or long-running world, treat modifier changes like configuration changes: record the current state, make a backup, change one planned setting, and verify it before the next session.

Available presets

Iron Gate's dedicated-server guide documents these preset names:

The preset name communicates the broad intent, but players should still review the resulting modifier summary in the current game. Avoid relying on an old screenshot as a permanent specification.

On a dedicated server, the documented pattern is:

-preset hard

Setting a preset overwrites earlier individual modifier choices. When combining a preset with individual modifiers, put the preset first and the overrides afterward.

Individual dedicated-server modifiers

The official server guide documents five configurable categories:

Example syntax:

-preset normal -modifier resources more -modifier raids less

This example is syntax guidance, not a recommended configuration for every community. Confirm the generated summary after startup.

Checkbox-style world keys

The official dedicated-server guide lists these -setkey values:

• nobuildcost
• playerevents
• passivemobs
• nomap

Example:

-setkey nomap

Do not confuse world keys with server visibility, crossplay, passwords, or save paths. Those are separate launch settings.

What each category changes

Combat

Combat settings alter the intended difficulty of fighting enemies. Review the setting with every member of a shared world; changing it can affect preparation and recovery expectations even when no map data changes.

Death penalty

Death-penalty settings change the consequences of dying. Before increasing the penalty, verify that players understand the setting and that a world backup exists.

Resources

Resource settings alter the rate at which supported resources are obtained. This affects the time needed for building and progression, so agree on it before a community begins gathering at scale.

Raids

Raid settings adjust event frequency. The separate playerevents key makes raid progression player-based rather than relying only on shared world progression, which may suit groups whose members advance at different speeds.

Portals

Portal modifiers change travel restrictions. Record the setting before planning transport routes; a world designed around one portal rule may be inconvenient when moved to another server with different modifiers.

World modifiers and Valheim 1.0 achievements

Iron Gate has confirmed that some world modifiers can affect achievement eligibility in Valheim 1.0. The official FAQ specifically identifies Hammer mode as a temporary cheat state that blocks certain achievements while active.

Do not assume that every preset or slider has the same effect. Review the current in-game warning and the official 1.0 FAQ before changing an achievement-focused world. Valheim Companion will update this guide after the public 1.0 build can be checked.

Changing an existing world safely

1. Ask all players to disconnect.
2. Stop the local game or dedicated server cleanly.
3. Create a dated offline backup of the world and configuration.
4. Record the current preset and individual modifiers.
5. Make the new configuration explicit rather than relying on memory.
6. Start the world privately and inspect the modifier summary.
7. Test saving and restarting before reopening the server.

Modifier changes do not replace world migration or terrain-generation decisions. Back up separately before Valheim 1.0 and review whether an old or new world is appropriate.

Dedicated-server configuration order

A readable launch configuration keeps related settings together:

valheim_server.exe -nographics -batchmode \
  -name "My Valheim Server" \
  -world "Dedicated" \
  -password "change-me" \
  -preset normal \
  -modifier resources more \
  -modifier raids less

The line breaks are illustrative. Use the format required by the operating system and hosting panel. Never publish a real server password.

Use the server configuration generator for the complete documented launch line.

Moving modifiers with a world

When transferring a world to another machine or provider, record the effective modifiers separately from the world files. A hosting panel may store launch arguments outside the save directory, and importing a world does not guarantee that the destination recreates the same server configuration.

After migration, check:

• the intended preset and individual overrides;
• portal and raid behavior;
• the networking backend and visibility;
• whether the expected world, rather than a new world, loaded;
• save and restart behavior.

Follow the interactive world migration checklist.

Official sources

• Valheim dedicated-server guide
• Valheim 1.0 FAQ
• Valheim support

Next: generate server settings or back up the world.