Valheim 1.0: worlds, saves and what carries over

Your worlds and characters survive the 1.0 update and stay playable, Iron Gate has confirmed this directly in its 1.0 FAQ. The Deep North will generate in your existing world, but only in terrain nobody has explored yet. If you've never sailed to the far northern edge of your map, you're fine. If you have, those ice fields keep their current empty layout and won't be regenerated. Iron Gate's own recommendation is to start a fresh world to fully experience the changes, which is the same advice it gave for Mistlands and Ashlands.

Valheim places biome content when terrain is first visited, so an update can fill in everything you haven't touched. This is why Mistlands and Ashlands both worked on old worlds as long as those regions were unexplored. The Deep North follows the same rule. Today's worlds already contain a placeholder Deep North: barren snow with nothing in it. Any of that placeholder terrain you've walked or mapped is locked in. Until September 9, the practical advice is simple: stay out of the far north on any world you plan to keep.

Characters are stored separately from worlds, and nothing in the 1.0 FAQ mentions any character reset. Your skills, inventory, and equipped gear all stay. That separation is also your middle path: if your old world has explored northern terrain, you can create a fresh 1.0 world and bring your existing character into it, keeping years of skill progress while getting clean generation. Move any items you want to keep into your inventory or ferry them through a portal-free trip between worlds, the same way world-hopping has always worked.

Achievement tracking starts when you download 1.0; nothing you did in early access counts retroactively. Iron Gate has also said that using cheats permanently locks eligibility, with limited exceptions it hasn't fully detailed. If you've used devcommands on a save in the past, it's not yet clear exactly how that history is treated, so the safe play for achievement hunters is a clean character on a clean world with the console left alone.

Full crossplay arrives with 1.0, but save transfer stays narrow: only Xbox and PC through the Microsoft Store version sync saves. There's no announced way to move a PC world to PS5 or Nintendo Switch 2. On mods, Iron Gate guarantees nothing at launch and notes updated mods take time after any patch. A modded world itself is normally fine once its mods are removed or updated, but expect a window after September 9 where most of the mod ecosystem is broken.