You’re deep in the Grand Reef, you just spotted your first Ghost Leviathan circling above a hidden alien cache, and the first thing you want to do is yell about it to a friend who’s equally obsessed with 4546B’s weird, dangerous ocean. That’s when the question hits: can you play 2 player on Subnautica? I’ve sunk over 300 hours into both the original game and Below Zero, and I’ve tested every co-op workaround available, so I’m breaking down exactly what works, what doesn’t, and how to get the best experience if you want to play with a partner.
Can You Play 2 Player on Subnautica With Official Support?
Let’s get the most common question out of the way first. There is no official 2 player mode for any version of Subnautica as of the latest game updates. Developer Unknown Worlds built the game from the ground up as a single-player experience, and the isolated, tense atmosphere of being stranded alone on an alien planet is core to its identity.
The devs have stated multiple times that adding official co-op would require rebuilding almost all of the game’s core systems, from resource spawning to creature AI to save file structure. That work would take years of development time, and they’ve chosen to focus on new projects instead of overhauling a game that launched back in 2018. There are no public plans for official 2 player support for either the original Subnautica or Below Zero.
That doesn’t mean you’re completely out of luck, though. The game’s active modding community has built a fully functional co-op mod that lets you play with one or more friends, as long as you’re on PC. It’s not perfect, but it’s stable enough for full playthroughs if you follow the setup steps correctly.
How to Set Up Modded 2 Player Subnautica Sessions
The only reliable, widely supported mod for co-op Subnautica is called Nitrox. It’s been in development for over 6 years, and the latest stable build supports full campaign play, base building, vehicle use, and all core game mechanics for up to 10 players (though 2 player sessions run the most smoothly). Nitrox is the only reliable mod for 2 player Subnautica sessions, so avoid any other random co-op mods you find on untrusted sites, as they’re usually outdated or full of malware.
Before you start, note that both you and your friend will need the same PC version of the original Subnautica (from Steam or Epic Games Store) and the same version of the Nitrox mod. Below Zero support is still in early beta as of now, so it’s not recommended for casual play. Follow these steps to get set up:
- Download the latest Nitrox mod installer from the official developer page
- Run the installer and point it to your Subnautica game folder to install the mod files
- Have one player host a session by opening the game, selecting "Multiplayer" from the main menu, and clicking "Host"
- Share your public IP address (or use a LAN connection if you’re on the same network) with the second player so they can join your session
If you’re playing over the internet, you may need to port forward 11000 on your router to let your friend connect, or use a free VPN like Hamachi if port forwarding feels too complicated. Disable any other Subnautica mods before installing Nitrox, as conflicting mod files will cause constant crashes or broken mechanics. Modded 2 player sessions only work for the original Subnautica, not Below Zero, as of the latest Nitrox stable release.
Top Tips for a Smooth 2 Player Subnautica Experience
Even with Nitrox running perfectly, you’ll run into small quirks that don’t exist in single player, because the game wasn’t built for multiple players. I’ve had sessions where my friend’s Seamoth vanished out of nowhere, or we both saw the same Reaper Leviathan in two different places, so I’ve picked up a few tricks to avoid those headaches.
First, sync your save files regularly. The host is the only one who stores the save file, so if the host crashes, any progress since the last save will be lost for both of you. I recommend saving every 15 to 20 minutes, especially after you complete a big milestone like building a base or finding the Cyclops blueprints.
Split up roles to make progression faster. One of you can focus on gathering base building resources like titanium and quartz, while the other scouts for new biomes and upgrades. It cuts down on grind a lot, and it’s fun to come back together and show off what you found during your separate explorations.
Avoid bringing both players near aggressive creatures at the same time. Creature AI is still a bit buggy in modded co-op, so a Reaper might target one player and completely ignore the other, or glitch out and attack out of nowhere. If you’re going into a dangerous area like the Crash Zone or Lost River, send one player first to scout, while the other stays back in a safe vehicle.
Don’t build bases too close to each other. Multiple base structures in the same area can cause frame drops for both players, even if you have a high-end PC. Leave at least 100 meters between separate base sections if you’re building individual areas for each player. If you run into constant crashes, try rolling back your Subnautica version to the latest stable build that Nitrox supports, because new game updates often break the mod until the Nitrox team pushes a patch.
Pros and Cons of Playing 2 Player Subnautica
A lot of people assume that playing Subnautica with a friend is automatically better, but it has both big perks and big downsides depending on what you like about the game. It’s not the right choice for every player, so weigh these factors before you go through the work of setting up the mod.
The biggest pros are obvious. The horror element is way less intense if you’re playing with someone else. If you’re the type of player who avoids deep biomes because you’re scared of running into a Reaper, having a friend with you makes those areas feel way more approachable. You also get to experience the story beats together, which is really fun if you’re both playing for the first time. Splitting resource gathering cuts down on grind a ton, so you can progress through the game way faster than you would alone.
There are real downsides too, though. The core lonely, isolated vibe of the game is completely gone. A big part of what makes Subnautica so memorable is that feeling of being the only human left on a hostile alien planet, and that goes away when you’re chatting with a friend the whole time. You’ll also run into glitches that you would never see in single player: missing resources, bugged creature spawns, crashed saves, and even broken story triggers if you’re unlucky.
If you’re playing Subnautica for the first time, I highly recommend finishing the single player campaign first before trying 2 player modded sessions. That way you get the full intended experience before you mess around with mods. If you don’t feel like dealing with mod setup and bugs, you can always do a couch co-op style session where one person plays and the other helps make decisions, which is a lot less hassle and still just as fun.
At the end of the day, the answer to can you play 2 player on Subnautica is a yes, but only if you’re willing to use mods and put up with a few small glitches. If you’ve already beaten the game a few times and want a new way to experience the alien ocean with a friend, modded co-op is an absolute blast. If you’re a new player, hold off on the 2 player experience until you’ve had a chance to play through the story alone first, so you don’t miss out on the tense, immersive atmosphere that made the game a classic. No matter what you choose, you’re in for hours of fun exploring the depths of 4546B.
