Valheim 1.0 and the Deep North: do you need a new world?
Existing Valheim worlds keep working in 1.0, but Deep North terrain generates properly only in unexplored areas. Learn whether to restart and how to back up a dedicated server before September 9, 2026.
You do not have to start a new world for Valheim 1.0. Iron Gate says old saves remain playable and receive new content. The limitation is terrain: Deep North biome generation only works properly in areas that have not already been explored.
Iron Gate still recommends a fresh world for the best complete 1.0 experience. Your choice is between preserving an established world and guaranteeing that every part of the finished world generates as intended.
Create a full backup before the first start on Valheim 1.0. The release has no public test branch, so server owners and mod authors will encounter the final build for the first time on September 9.
Existing world or new world?
| Choose | Best when | Tradeoff |
|---|---|---|
| Keep the existing world | Your group values its builds and progression most | Previously explored northern terrain will not regenerate as the finished Deep North |
| Start a new 1.0 world | Your group wants the complete intended biome generation and progression | You leave old builds and exploration behind |
| Keep both | You want a safe launch-night test before deciding | Requires a second world name or restoring a backup later |
The third option is safest for a long-running community: preserve the current world, generate a separate 1.0 world, and let the group decide after testing.
What “unexplored” means
The official Valheim 1.0 FAQ says new biome generation only works properly in areas that have not yet been explored. Iron Gate's general Valheim FAQ describes explored terrain as an area where a player has set foot, including a radius of about 500 metres.
That means:
- Unvisited northern zones should receive the 1.0 Deep North generation.
- Terrain a player has already walked remains as it was when loaded.
- A fresh world is the only way to guarantee complete 1.0 generation.
Do not treat “stay south of the snow line” as an official rule. Iron Gate recommends starting over for the best complete experience.
Prepare a berrybyte server
Do this before starting the server after the 1.0 update becomes available.
Stop the server
Open the Valheim server in the dashboard and press Stop. Wait until it is fully offline so the world database is not being written.
Create a full backup
Open Backups, create a backup, and wait until it reports completion. Use a recognizable name such as Before Valheim 1.0.
Record the current world and mods
In Settings → Game Settings, note World Name and whether Enable Crossplay is on. If the server is modded, save a list of the installed BepInEx plugins and versions.
Choose the launch world
Keep the current World Name to carry it forward. To generate a separate world, enter a new
name after 1.0 is live. Never rename only one file in a manual .db and .fwl pair.
Start once on the 1.0 build
Keep Auto Update enabled and start the server after Iron Gate releases 1.0. Watch the console until the world finishes loading before inviting players.
Verify before exploring north
Join, confirm the correct world and builds loaded, then create another backup. Only after that should players travel into previously untouched northern zones.
If you keep the existing world
Keep the current world name and avoid visiting more northern terrain before September 9. Once 1.0 is installed, unexplored regions can generate the new content when players first approach them.
This preserves bases, progression, and the existing seed, but it cannot repair Deep North zones that were already generated.
If somebody scouted the far north months ago, assume the nearby terrain was loaded even if they did not build there. Use the pre-1.0 backup and a separate test world rather than discovering the limitation after the whole group travels north.
If you start a fresh 1.0 world
Wait until the live 1.0 dedicated-server build is installed, then change World Name to a name that has never been used on the server. Start the server to generate the new world.
Do not delete the old world or its backup. You can switch back by stopping the server, restoring the backup or selecting the original world name, and starting again.
Protect manual world files
A Valheim world is a matching pair:
<WorldName>.db
<WorldName>.fwlStop the server before copying or replacing them. Preserve both files under
the same world name, plus adminlist.txt, bannedlist.txt,
permittedlist.txt, and any .old or _backup* siblings. On a self-hosted
server they usually live in worlds_local under
%USERPROFILE%\AppData\LocalLow\IronGate\Valheim on Windows or
~/.config/unity3d/IronGate/Valheim on Linux. A full berrybyte backup is
safer because it also captures server settings and mod files.
Mods on release day
Iron Gate explicitly says it cannot guarantee that mods will work when 1.0 releases. There is no official mod support, no Steam Workshop integration, and no pre-release public test branch for 1.0.
For a modded server:
- Make the pre-1.0 backup.
- Record BepInEx and every plugin version.
- Remove BepInEx and mods before the first 1.0 start. Iron Gate gave the same advice before Ashlands: leaving the loader in place often prevents the game from launching.
- Check each mod author's 1.0 compatibility notice.
- Add confirmed-compatible mods back in small groups.
Console versions do not support mods for 1.0. If the group is moving to cross-platform play, test an unmodded copy instead of assuming the existing client modpack can work for console players. Until the BepInEx rewrite ships here, see Installing BepInEx Mods.
For installation and joining steps, continue with Set up a Valheim dedicated server and Join a Valheim server.
Frequently asked questions
Do I need a new world for Valheim 1.0 and the Deep North?
No. Iron Gate says old saves remain playable and receive new content. However, Deep North biome generation only works properly in areas that have not been explored, and Iron Gate recommends a fresh world for the best complete 1.0 experience.
What counts as explored terrain in Valheim?
The 1.0 FAQ says new biome generation only works properly in areas that have not yet been explored. Iron Gate's general FAQ describes that as an area where a player has set foot, including a radius of about 500 metres. A fresh world is the only way to guarantee complete 1.0 generation.
What should I back up before Valheim 1.0?
Create a full server backup before the first 1.0 start. For a manual world-only copy, keep the matching <WorldName>.db and <WorldName>.fwl files together. Also record the server version and installed mods.
Will BepInEx mods work with Valheim 1.0?
They may not work on release day. Iron Gate says Valheim has no official mod support, there is no pre-release 1.0 public test branch, and mod authors may need time to update BepInEx and individual mods.
When does Valheim 1.0 release?
Valheim 1.0 and the Deep North launch on September 9, 2026 for PC, Linux, Mac, Xbox One, Xbox Series X|S, PlayStation 5, and Nintendo Switch 2.