Will Deep North Break Already-Explored Areas?

Will the Deep North update break already-explored areas in my world?

One of the most-asked questions from server admins running long-lived "forever worlds": if we have already been around the northern part of the map, does the Deep North still appear there, or do we need a new world to see it? The Deep North shipped with Valheim 1.0 on 9 September 2026, and this page answers the question from the game files of the current build, 1.0.17, so it describes what the server actually does rather than what players assume.

Checked against Valheim 1.0.17, October 2026.

The short answer

Your builds and characters are safe. What you lose in already-explored northern areas is the new content placed there: Valheim fills each 64-metre zone with its trees, rocks, ore, creature spawners and locations once, the first time the zone is generated, and never again. Explored northern zones keep what was placed there before 1.0, so they get none of the Deep North's new places or vegetation. Zones nobody has generated get the full biome. Creatures are the exception: the game spawns them by biome as you play, so Deep North creatures still roam explored ground. Iron Gate's 1.0 FAQ says the same: biome generation only works properly in areas that have not been explored, and it recommends a new world for the Deep North.

Why this happens (the technical mechanism)

The game files split a zone into two parts. The ground and the biome are not stored at all: the world generator recalculates them from the world's seed every time a zone loads. What is stored is everything placed in the zone when it was generated, from trees and boulders to dungeons and the boss altars, along with whatever players built or dug. The server keeps a list of generated zones and only places content in zones that are not on it.

That is why a new version cannot add its new places to an explored zone, and why your builds survive: nothing the game placed or you built is ever regenerated. It is the same mechanism that decided how much Mistlands and Ashlands content older worlds received.

How to check what's "explored" in your world

"Explored" means generated, and the server generates far more than anyone walks through. With the default simulation distance it generates every zone up to four zones away from the one a player is standing in: a square of 9 by 9 zones, about 576 metres across, around every player, all the time. The higher simulation distance settings reach further. So:

• Walking or riding through an area generates everything at least 250 metres to each side of your path.
• Sailing along a coast generates the same band of land and sea on both sides of the boat.
• Your in-game map shows less than what is generated. The map records what your character saw; the server's list of generated zones is wider, and it is shared by everyone who played on the world.

Assume that if anyone has sailed the northern shore, the land up to a few hundred metres inland is generated.

If your world has not reached the far north yet

• Tell everyone to stay out of the far north until the group is ready to play it. Every voyage north generates a band of zones on both sides of the boat.
• Do not teleport admins north to scout. Arriving generates the zones around the arrival point like any other visit.
• Keep the group's play in the south until you are ready: the Deep North starts about 8,000 metres from the world centre, on the northern side, so the rest of the map is safe to explore.

What you can NOT do

• Reset explored zones with a console command. There is none. The genloc command, the nearest thing, places locations again but only into zones nobody has generated yet, so it cannot bring Deep North places to explored ground. Mods that claim to reset zones rewrite the world file; treat them as a risk to the world.
• Keep the world but start the north fresh by deleting world files. The seed lives in the world's metadata file, and deleting the world data leaves you the same seed with nothing built, which is just a new world with extra risk. Create a new world with the same seed instead if that is what you want.
• Run a third-party world cleaner without a backup. Make a verified copy first and check the tool author's notes for 1.0; an untested database rewrite can turn a planning problem into data loss.

The forever-world fallback if you already explored the north

If your group has already explored most of the far north, you have three options:

Whatever you pick, tell the group in advance, so players can take screenshots of their builds and empty their storage onto their characters before the move.

What happens to existing builds on the Deep North coastline

A base on the northern coast stays exactly where it is: builds are stored objects, and stored objects are never regenerated. If your base sits at the very edge of the explored area, the ungenerated zones just north of it get the full Deep North, which makes the old base a forward outpost for expeditions north.

The character question

Characters are saved on each player's own machine, not in the world, and the server stores none of them. A character levelled in the old world joins a new world with its skills, inventory and known recipes. What stays behind is per-world: each character's map, bed spawn point and home point are kept separately for every world.

The only catch: a character geared past the new world's progression starts ahead. Some groups start fresh characters for a clean run; others keep their characters but agree not to use old-world gear until they reach that tier again. Decide together before the move.

Related articles

• Start a new world or keep your old one? The decision this mechanic feeds into
• Deep North & 1.0 server readiness checklist
• Building bases that survive update transitions
• Migrating a world to a new server
• Character files between worlds

For a managed Valheim server that lets you run multiple worlds for clean migrations between campaigns, see Supercraft plans.