Valheim World Modifiers on a Dedicated Server

Valheim's world modifiers are the game's official difficulty system — combat scaling, death penalty, resource rates, raid frequency and portal rules. In single-player or a player-hosted game you pick them on the Join World screen. On a dedicated server nobody ever sees that screen, so they are set as launch arguments and enforced for everyone who joins.

That difference is the whole subject of this page. On your hosted Valheim server the arguments go in the Startup tab, alongside the rest of the server settings. This guide covers all three argument families, the ordering rule that silently discards half of them, what each value actually does, and how to change modifiers on a world that is already running.

What changes when the world lives on a dedicated server

Valheim has no config file, so there is nothing else to edit. Everything below is either a Startup field or an extra launch argument.

The three argument families

Iron Gate's dedicated server guide documents three, and they stack:

-preset — the whole profile

Iron Gate lists the valid values as Normal, Casual, Easy, Hard, Hardcore, Immersive, Hammer, and is explicit about what a preset does to anything you set before it:

"-preset hard - Sets world modifier preset. Setting a preset will overwrite any other previous modifiers."

-preset hard

-modifier — one dial at a time

-modifier combat hard -modifier resources muchmore -modifier raids none

Each is its own -modifier argument — there is no comma-separated form.

-setkey — the checkboxes

-setkey nobuildcost -setkey passivemobs

Iron Gate documents four valid values: nobuildcost, playerevents, passivemobs, nomap.

playerevents is the one worth knowing about on a server with players at different stages: without it, raid difficulty tracks the world's boss progress, so a new player in the Meadows gets whatever the world has earned.

Order matters — -preset first, then everything else

The server reads arguments in sequence and a preset overwrites what came before it. Iron Gate's guide says of -modifier: "If combined with a preset should be set after."

So write the preset first:

-preset casual -modifier resources most -setkey nobuildcost

Reversed, the trailing -preset casual silently flattens the resource change and the build-cost key back to the preset's own values. Nothing errors and nothing is logged — the server simply starts with settings you did not ask for. This is the single most common reason a modifier "does not work".

What each setting actually does

Iron Gate publishes the accepted values but not their effects. The numbers below come from the community Valheim wiki, read 9 September 2026 — treat them as well-maintained community documentation rather than a developer specification, and expect 1.0 to shift some of them.

Combat — percentages of the normal value:

Hard and Very Hard also raise the chance of spawning starred enemies.

Death penalty — the setting players will notice first:

casual is the one to reach for on a server with newer players: keeping equipped gear removes the corpse-run spiral that loses people their whole kit in a biome they cannot survive.

Resources — a multiplier on drops from mobs and lootable objects:

The wiki notes two exceptions worth knowing before you promise your players anything: the multiplier rounds up, so 1.5x behaves like 2x on many drops, and it does not affect fish, trophies or boss drops.

Raids — read this table carefully, because the percentage runs backwards:

A higher event rate means a longer gap between raids. At normal the game rolls a 20% chance every 46 minutes.

-modifier raids none does not remove every attack

The wiki is explicit that night raids still occur with the event rate set to none. If your players report being attacked on a "no raids" server, this is why — it governs base raid events, not everything that comes at you after dark.

Portals — casual allows everything through portals, hard and veryhard restrict them progressively, up to no portals at all. Iron Gate does not document which value maps to which restriction, and the wiki describes the portal states without tying them to the argument values, so confirm in game before you build a server rule around it.

Changing modifiers on a world that is already running

This is the question the wikis answer badly, and the answer is yes — there are three in-game admin commands:

They run from the F5 console and take effect on the live world, with no restart. They are admin commands, not cheats — the community wiki lists them under admin commands, "only available when player's SteamID64 or Crossplay player ID is in the admin list", which is the category that works on a dedicated server. Get your ID into adminlist.txt first; Valheim Console Commands covers that and the console itself.

setkey is a different command and will not work

The in-game setkey and resetkeys are cheat commands. The wiki is blunt about that whole category: "The cheat commands are available in singleplayer or manually hosted mode only. They do not work on a dedicated server." Only the launch argument -setkey gets you those four checkboxes on a server. Do not follow a single-player guide that tells you to type setkey nobuildcost into the console.

There is no way back to "normal" on a single dial

The wiki records a genuine one-way door: once you have changed a modifier away from normal with setworldmodifier, setting it back to normal does not work. Its example is portals — setworldmodifier portals casual applies, but setworldmodifier portals normal does not undo it. The documented escape is setworldpreset default, which resets every modifier set this way, not just the one you wanted to fix. Change one dial live, and you may have to reset all of them to get back.

Because of that, treat the console commands as the tool for a trial — turning raids off while a group rebuilds, softening the death penalty for an evening — and the Startup tab as where the server's real, permanent configuration lives.

Iron Gate does not document these three commands

Their dedicated server guide is dated 11 April 2024 and covers only kick, ban, unban and banned under console commands. The three above are community-documented, and some older host guides claim they need devcommands or the Server devcommands mod. Our reading of the wiki's own categories says they do not, but run one and read what the console prints back before you rely on it in front of your players.

Modifiers belong to the world, not to the server

World modifiers are stored as global keys, which the wiki describes as the mechanism used "to track progress in game worlds" — the same place boss kills live. They are world state, saved with the world.

The practical consequences on a server:

• Point -world at a different world and you are looking at a different set of modifiers.
• Upload a world from single-player and it arrives carrying whatever modifiers it was created with — see How to Upload Your Existing World to Your Valheim Server.
• Wipe the world and the modifiers go with it, back to whatever your launch arguments say on the next boot.

Hammer, and the achievement question

Hammer is a valid -preset value; Iron Gate lists it. Separately, Iron Gate's 1.0 FAQ says this about achievements:

"Some world modifiers such as hammer-mode will also block certain achievements. Hammer-mode counts as a temporary cheat."

What Iron Gate has not actually said

The FAQ names "hammer-mode". The dedicated server guide lists Hammer as a -preset value, in a document dated 11 April 2024 that predates achievements entirely. No Iron Gate document connects the two names, and we are not going to tell you they are the same setting on the strength of a matching word. If achievements matter to your players, do not run a Hammer preset on that world until you have checked in game — and if you want a free-build server, run it as a separate world you have already written off.

The wider achievement rules matter more to server owners than the hammer question, because 1.0's cheat flag attaches to the world save rather than to one player. Valheim Console Commands has the full quote and what triggers it.

Applying changes

Launch arguments are read once, at startup. Set them in the Startup tab, save, and restart — there is no way to push them to a running server. The in-game admin commands above are the only route to a live change, with the one-way-door caveat attached.

What to read next

• Valheim Server Settings and Launch Arguments — every other argument, plus admins, bans and world management
• Valheim Console Commands — enabling the F5 console, adminlist.txt, and the 1.0 achievement rules
• Valheim 1.0: What Changes for Server Owners — what launch day changed
• Managing your Valheim server — restarts, backups and player moderation
• How to Upload Your Existing World to Your Valheim Server — bringing a world across, modifiers and all

FAQ

What are the world modifiers in Valheim?

Five sliders — combat, death penalty, resource rate, raids and portals — plus four checkboxes: no build cost, player-based raids, passive enemies and no map. Together they are Valheim's official difficulty system. On a dedicated server they are set with the -preset, -modifier and -setkey launch arguments rather than on the Join World screen, which means the server decides for everyone.

Can you change world modifiers mid-game in Valheim?

Yes. An admin can run setworldmodifier [name] [value] or setworldpreset [name] from the F5 console and it applies to the running world with no restart. Two catches: your ID has to be in adminlist.txt first, and you cannot put a single modifier back to normal afterwards — the only documented reset is setworldpreset default, which clears every modifier you set that way. For permanent settings, change the launch arguments and restart instead.

How do I change world settings on a Valheim dedicated server?

Add the arguments in the Startup tab and restart. Put -preset first if you use one, then your -modifier arguments, then -setkey:

-preset casual -modifier deathpenalty casual -modifier raids less -setkey playerevents

There is no config file to edit — Valheim reads its entire configuration from the command line.

What are the best world settings for a Valheim server?

There is no universal answer, but for a mixed group of friends the settings that cause the fewest arguments are -modifier deathpenalty casual (players keep equipped gear, so a bad death is not a lost evening), -modifier raids less if people want to build, and -setkey playerevents so newer players do not get raids scaled to the world's boss progress. Leave combat and resources at normal to start with — they are easy to adjust later, and most groups discover they wanted a gentler death penalty rather than an easier fight.

Why did my world modifiers stop working?

Almost always argument order. A -preset placed after your -modifier arguments overwrites all of them, silently. Put -preset first. If the order is right, check that each modifier is its own -modifier argument and that you restarted — Startup fields do nothing until the server restarts.

Do world modifiers affect achievements?

Iron Gate's 1.0 FAQ says "some world modifiers such as hammer-mode will also block certain achievements", counting hammer-mode as a temporary cheat. It does not list which other modifiers qualify, and it does not connect hammer-mode to the Hammer value of -preset. If achievements matter on your server, keep experimental settings on a separate world.

Do modifiers carry over if I switch worlds?

No. Modifiers are stored as global keys inside the world itself, so each world carries its own. Change -world and you get that world's settings; upload a single-player world and it brings the modifiers it was made with.

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