Getting a co-op session in Permafrost running is not hard once you understand one simple rule: cooperative play only happens through the host’s world. Everything in this guide follows from that. I have run sessions, joined friends, and banged my head against a session browser that refused to show anything, so let me walk you through hosting, joining, and what to do when the obvious steps fail.
Hosting a Session
From the main menu, go to Play and choose Host Multiplayer. You will then decide whether to load a world you already have or spin up a fresh one for the group.
Before you start, handle the settings that decide who can get in. Set a password and pass it along to the people you want in the lobby. Pick a max players value that gives your whole group a slot, not just the first person who clicks. Most importantly, switch Private to OFF — if it stays on, your friends will never see the session in the browser, no matter how many times they refresh.
Kick off the session and let the world finish loading.
Here is the part that trips people up: only Host Multiplayer creates a session others can join. If you load the same world in solo, the game gives you no lobby to share. To keep a group run going across multiple play sessions, the host needs to load that same world the next time everyone gets together — a different world means a different game as far as your friends are concerned.
Joining Someone Else’s Game
On your end, head to Play and pick Join Multiplayer Sessions. Look through the session browser for your friend’s world. When you spot it, enter the password if the game prompts you, then wait for the world to load in.
One thing worth knowing before you get attached to a character: you are joining the host’s world, not your own. Characters belong to the world they were created in, so the survivor you have been building up solo will not follow you into someone else’s session.
When You Cannot Find or Join the Session
If the session refuses to appear, the host almost certainly loaded a world in solo mode instead of through Host Multiplayer, or left Private switched on. Both have to be corrected before the lobby exists for anyone else.
A password error usually just means the two of you are working from different passwords. Ask the host for the current one and watch for stray spaces at the start or end when typing it in.
If the browser tells you the session is full, the host can raise the player limit in the session settings and restart the lobby.
That “wrong character” or missing character feeling has a mundane cause — the host did not load the same world as last time. Reloading the previous world brings everyone’s tied characters back.
For stubborn connection problems, first confirm you and the host are both on the latest version of the game, then close Permafrost completely and relaunch it on both ends before trying again.
When none of that shakes it loose, there are a couple of community workarounds worth trying. One that people report success with involves moving further into the map together: head past the cabin, push beyond the cave, and continue a little way beyond that point. Others have had the session browser cooperate after spamming the reload list a bunch of times and then fully rebooting the game. Neither method is guaranteed, but both cost you almost nothing to attempt while you are already stuck.