Valheim 1.0 and Deep North on your serverKeep the old world or start over?

Published on September 10, 2026 · last updated on October 21, 2026

Does my existing world keep running?

Yes. In the official 1.0 FAQ, Iron Gate explicitly states that old saves stay where you last left them and can still be played. Characters are not affected anyway: in Valheim, they are always stored locally with each player and travel with them from world to world.

Your server with us is brought to the new version automatically after the update - with a jump of this size, that is half the battle, because Valheim only connects client and server when the versions match exactly. So you neither have to order a new plan nor move the world by hand.

The catch: biomes only appear in unexplored areas

This is the actual point, and it surprises many groups. Iron Gate puts it like this in the 1.0 FAQ: biome generation only works properly in areas that have not been explored yet.

The reason lies in the way Valheim saves a world. As soon as someone has entered an area, the generated terrain is written permanently into the world file. If an update then changes the rules of world generation, the new rules only apply where nothing has been written yet. In a world that has been played for a long time, that means: the new north appears at the outer edge of your known map, not in the middle of your home territory.

For the complete experience, Iron Gate therefore recommends a fresh start. That is a recommendation, not a requirement - a grown world stays playable, you just do not see everything.

Keep it or start over - weighing it up

A middle course that many groups choose: leave the old world in place and start a new one alongside it. Because a Valheim server always serves exactly one world, you simply switch the world name back and forth - both world files are kept. If you do not want to give up your home base but still want to see everything, this is the best way.

How the switch works in detail is explained in Start a new world. If, the other way round, you want to bring a world you started locally onto the server, Upload your own world explains the way via the two world files.

Mods: wait first, then catch up

The most unpleasant part of a big update hits modded servers. Iron Gate is clear on this: there is no official mod support, and therefore no guarantee that mods will work after the 1.0 release.

In practice, that means: expect part of your collection not to load at first. BepInEx itself is not a neutral bystander either, but depends on the game version - so an update can disrupt not just individual mods, but the start of the server as a whole.

The clean approach:

1. Make a copy of the world files before the update.
2. Empty the plugins folder or put its contents aside.
3. Start the server unmodified and check that it starts cleanly.
4. Bring the mods back one by one as soon as their authors have released a version that fits 1.0.

One at a time instead of all at once is not an overcautious ritual: if ten mods come back at the same time and the server does not start, the search begins all over again. If the connection stays shaky afterwards, Fix connection problems goes through the usual causes.

Before the update: the short list

• Back up the world files. Download the .db and the .fwl before anything happens - more in Create backups.
• Write down your mod list. A plain text file with mods and versions saves a lot of searching later.
• Deactivate mods. Start vanilla, then rebuild step by step.
• Tell the group whether you keep the old world or start over. Nothing causes more frustration than an unexpectedly empty map.
• Check crossplay if new players on PS5 or Switch 2 are supposed to join - see Set up crossplay.

The game's own backup copies explicitly do not count as a backup: they are stored on the same server and fail you exactly when you need them most.

Does a 1.0 world need more performance?

The rule of thumb for Valheim remains unchanged: it is not the number of players that drives the requirements, but the size of the world. Every object you build and every area you explore ends up permanently in the world file, and a map that has grown over months needs noticeably more memory than a freshly generated one.

1.0 changes nothing about the player limit - Iron Gate still describes Valheim as a game for 1 to 10 players. If you want more Vikings in one world, you still raise the limit with a server mod, which then restricts the group to PC players. The background is in Slots explained.

If you are starting fresh for 1.0 anyway, it is a good moment to reconsider your plan: a new map starts small and grows again. Guideline values across several games are collected in How much RAM do I need?, and with us an upgrade is possible at any time without losing world or configuration.

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