Subnautica 2 Co-op Guide

Subnautica 2 was released in Early Access on May 14, 2026. The main innovation that distinguishes the sequel from the first part is full support for online play from day one. Now you can play through the game from beginning to end with up to three friends, or, if you wish, go solo.

Key Co-op Features:

Firstly, the game was originally created with multiplayer in mind. Developers from Unknown Worlds Entertainment stated that they built Subnautica 2 "from scratch" as a single-player game with optional co-op. This means that co-op mechanics are not tacked on as an afterthought, but are carefully thought out at the game design level.

Secondly, the maximum number of players is four. You and three friends can explore the underwater world, build bases, and fight leviathans.

Thirdly, the game supports cross-platform play. It doesn't matter who has a PC and who has an Xbox Series X|S — you will still be able to play together.

How Co-op Works: Mechanics and Rules

How to Create a Multiplayer World and Invite Friends

The process of starting a co-op game is simple and intuitive.

Hosting a game. On the main screen of Subnautica 2, select "Host Multiplayer". Create a new world or use an existing solo save — the game allows you to convert a single-player file to multiplayer and back at any time. Choose your game mode — Survival (you need to monitor hunger, thirst, and oxygen) or Creative (unlimited resources and no restrictions).

Inviting friends. Open the menu and go to the "Friends List" tab. If you are friends on the same platform (Steam, Xbox), simply send an invitation. If you are playing on different platforms, generate an 8-digit code and send it to your friend. They will enter the code in the "Add Friend" field, and you can accept their request.

Joining a game. On the main screen, click "Join Friends". All active games from your friends list will be displayed there. Simply select the desired one and connect.

Main Co-op Mechanics

Here's how co-op gameplay is set up.

Free movement. Unlike some co-op games, there is no distance restriction here. Each player can swim anywhere, even to the other side of the map. No need to "drag" friends along.

Drop-in/Drop-out system. Friends can join and leave the game at any time without restarting the session. Even if you have already completed half the story, a friend can enter your world and play with you. However, any story moments they missed will remain missed.

Shared inventory and overall progress. This is both convenient and potentially conflict-inducing. All chests and storage units in the world are accessible to all players. If you put a rare resource in a box, one of your friends might take it. However, each player's personal inventory remains private — what's in your backpack, no one will touch. The developers promise to add the option of non-shared inventories in the future, but at the start of early access, the system works this way.

Shared blueprints and scans. The most useful aspect of co-op. If one player scans a new creature or finds a blueprint, everyone else automatically gets it. No need to chase everyone around the map — one scans, everyone crafts.

Joint base building. You can build a common base with your whole squad, or each can build their own — complete freedom.

Important Features to Know

Respawn. There are bioreactors in the game that serve as respawn points. Multiple players can be linked to one bioreactor. If someone dies, they will respawn at the last activated bioreactor.

Ping system. By pressing V (on PC), you can place a marker on the map and indicate to friends where to swim. This greatly simplifies coordination when you are not in voice chat.

Progress difference issue. If a friend joins your world where you have already progressed far in the story, they will miss the beginning of the story. They will start from a "beginner's" capsule, and you will have to swim to them on a Tadpole to pick them up. However, this is easily resolved: assemble a tool kit for the newcomer (scanner, swim fins) and hand it over to them. They won't have your upgrades, but they will catch up over time.

The host is primary. Only the creator of the save can enter this world alone. When the host is offline, other players will not be able to access their save. So if your friend with the most beautiful house is offline, you won't be able to get in until they return.

Save conversion. The save file can be switched between single-player and multiplayer modes as many times as you like. Started playing solo, then decided to invite a friend — convert. Tired of co-op — convert back. All construction and progress will be saved.

How Cross-Platform Works in Subnautica 2

Subnautica 2 supports play between PC (Steam, Epic Games Store) and Xbox Series X|S. To play on console, you will need an Xbox Game Pass Essential, Premium, or Ultimate subscription. The process of adding friends from another platform is described above — via 8-digit codes.

Cross-progression. Yes, Subnautica 2 supports this too. You can start playing on PC, save to the cloud, and then download the same file to Xbox and continue. This requires linking an Unknown Worlds account and having cloud saves enabled.