Permafrost co-op: host a multiplayer world and join one

Source-backed host and join steps from the Steam Community multiplayer guide, plus the Steam-invite state after the 12 October 2026 patch and what is not yet independently verified.

Answer: Start a world through Play > Host Multiplayer, then reach the cabin before guests join. Guests launch the game and stay at the main menu before accepting a Steam invite, or use Play > Join Multiplayer Sessions and the host's password. This is the developer's written guidance, not our connection test.

Version scope

Steam Windows EA · developer update 16 Oct, re-read 2026-10-18

Game status

Early access

Hub directory

Permafrost

Verified

2026-10-13

Updated

2026-10-18

What hosting a co-op session looks like

The Steam Community multiplayer guide recommended by the developer-pinned known-issues post puts hosting on the Play > Host Multiplayer entry of the main menu. From there the host creates or selects an existing world, sets a password and a player cap, then launches the session. This guide is the source for those menu entries; it is not a step-by-step we re-tested ourselves. Treat the host flow as the documented path, not a benchmark.

The guide also makes the boundary explicit: solo loading is not a co-op session, and continuing an existing run requires the host to load the same world; both clients should be up to date. Solo saves stay with the single-player world the character was created on; a friend's world does not receive that character.

Joining an existing session

A guest starts the game and lands on the main menu, then either accepts a Steam friend Join Game / chat invite, or opens Play > Join Multiplayer Sessions, picks the session and enters the password. Either entry point is what the Vintage guide lists. The guide does not describe any console entry point; this article only covers the Steam Windows build.

Current co-op precondition and the Steam invite reality

The developer-pinned discussion thread (updated 16 October 2026, re-read 18 October 2026) still states the current precondition: a guest must have the game already running and parked at the main menu, and the host must already be at the cabin before guests can join. This rule is the developer's current written guidance, not a separately tested flow on this site — a real join was not run this round.

The 12 October 2026 official news post focuses on Steam-invite fixes and recipe pin behaviour; that post and the updated Vintage guide are the current source for invite behaviour. The cabin + main-menu precondition above is the boundary the pinned discussion names today; this article reports it as developer text, not a tested join.

The same Oct 12 post addresses Steam invites that were reportedly not working before; treat invite acceptance as patched but not as a guarantee that every invite handshake succeeds on the first try. The guide suggests checking both clients are updated, restarting the game and trying again; it does not guarantee a successful connection.

Troubleshooting checklist (only what the guide says)

These checks are listed by the Vintage guide or the developer discussion, not by this site:

• Confirm the entered password matches the host's password with no extra spaces. The guide's extra-space check is not a rule that all spaces within a password are invalid.
• Confirm the host's player cap is high enough for the joiner.
• Confirm the host loaded the same world as last time and both clients are on the latest patch.
• Restart both clients after a failed join before retrying.

The guide does not ask the reader to disable firewalls, antivirus, secure-boot, or Steam Guard. This article does not invent those steps and does not promise them as fixes.

What this guide does not verify

The following are not independently confirmed in this round and are not claimed here:

• A clean measurement of matchmaking time, invite round-trip latency, or session stability over hours.
• A confirmation of the host-must-be-at-cabin pre-condition from a live co-op session; the cabin + main-menu pre-condition is reported as the developer's current written guidance only.
• A separate confirmation that controller-driven co-op menu navigation survives the same flow as keyboard navigation.
• A worked example of a guest recovering progress after the host disconnects mid-session.

The three promotional images paired with the sections are official Steam promotional images for Permafrost; they are included for visual atmosphere only and are not evidence of any specific menu location, button prompt, or session flow.

Source

Verification carried out on 2026-10-13 against the Steam Community multiplayer guide and the 12 October 2026 official Steam news post; the developer-pinned discussion thread was re-read on 2026-10-18 against the developer's 16 October 2026 update text. The cabin + main-menu precondition reflects that re-read and is reported as developer text, not a tested join. See the sources panel on this article and the permafrost hub page.

Correction

Our earlier quick-fact summary shortened the password check to "no spaces". The documented check is for extra spaces in the entered password, not a blanket claim about every valid password character. This is a wording correction, not a new connection test or a guarantee of a successful join.