4Game

I just wanted to raise awareness of this mod, as it once again saved my seed (OK, that's a bit dramatic but it easily could've, as it did do it in the past) that I've put hundreds of hours into. Basically, it allows you to introduce newly released content into already explored parts of the world and it does it in such a wonderful, non-cheaty way. If you're firmly against mods, you can install it, use it and uninstall it, as it doesn't "taint" the seed – all that it does is what the vanilla game can do.

It was specifically made with tar pits in mind, but the author is updating it constantly (in fact, it was last updated yesterday) and only today I've noticed it also allows to reroll unlooted chests in the Mountain biome for a chance to get onion seeds, which I was really struggling with until I used this mod again. First time I used it was for tar pits and it worked wonders – the tar pits were there as if they were always there. They didn't float in the air, they weren't glitched, they didn't overlap any points of interest (like Fuling bases, stones, birch forests, etc.) that I already explored. I was honestly gobsmacked how well it executed the command.

You can very finely tune what you want to do. Or, if you don't want to get into the plethora of parameters, there are simple commands to introduce just tar pits or onion seeds.

What I'm most excited about though is the ability to regenerate all explored zones apart from ones that you specify with coordinates or that are a specific distance from your character, or in a specific biome, or at specific coordinates and distance, or… This means that you never have to worry about abandoning your mostly already explored world when new content gets introduced, because you can preserve your builds and reset everything else to a state as if the world was just generated.

It's the only mod I use as it doesn't feel like cheating. Just some peace of mind.

Applying mods to Valheim isn't exactly straightforward, but if I've done it, I'm sure you can, too. Just remember to back up your world before you use it, as it could wipe your builds if you use it improperly (that would probably only happen if you started playing around with the more complex, parameterised functions though, so you would probably be well aware of what you're doing anyway) – check that it's all there after utilising it.

Upgrade World at Valheim Nexus Mods

It was made by an active member of our community, u/Wethospu_ (thanks again!) and he first advertised it in this post. Please give him some love if you find this useful, as I think he didn't get even fraction of the recognition he should have got for the fantastic job he did with this mod (his guide on exploding silver veins got him way more updoots, and I find this fact, as good as the guide was, criminal).

Sorry for the wall of text but I just can't get over how good this mod is (and no, this isn't the author's alt-account).