Subnautica 2 multiplayer and crossplay

Party size and play modes

Steam describes Subnautica 2 as a single-player experience that can optionally be played in online cooperative multiplayer with up to three friends. That makes the total squad size four players. Solo play remains a first-class mode rather than a lobby requirement.

Crossplay evidence

The Steam response includes the Cross-Platform Multiplayer category, and the Xbox US listing advertises cross-platform co-op. Those labels establish intended support, but they do not document every invitation flow. Account requirements, platform friends lists, and error states still need a live test.

What Buddy System changed

The official Early Access 1.2 update adds proximity voice chat, player revives, player trading, emotes, and two new characters. This makes squad communication and cooperation more expressive, but feature behavior may change in later patches.

FeatureAdded in 1.2Current evidence
Proximity voice chatYesOfficial update
Player revivesYesOfficial update
Player tradingYesOfficial update
EmotesYesOfficial update
Two new charactersYesOfficial update

Before you invite a crew

Confirm which store account owns the game, whether both platforms use the same regional availability, and whether voice-chat permissions are enabled at the system level. If a platform combination fails, record the exact versions, region, error text, and invitation method before calling it a crossplay problem.

Evidence boundary

This page does not claim that every Xbox/Steam invitation path has been hands-on tested. Setup steps will be expanded only after a controlled cross-platform session is captured and version-stamped.

Direct answer

Subnautica 2 supports solo play or online co-op for up to four players. Steam and Xbox advertise cross-platform play, and update 1.2 added proximity chat, revives, trading, and emotes.

Sources and limitations

SourceTierCheckedLimitation
Steam Appdetails APIA2026-08-27Store categories do not replace setup testing
Xbox US listingA2026-08-27Crossplay labels need live invitation testing
Official 1.2 Buddy System updateA2026-08-27Retest after each patch

FAQ

How many players can join a Subnautica 2 session?
The official description supports one solo player or online co-op with up to three friends, for four players total.
Does Subnautica 2 support crossplay?
Steam and Xbox both advertise cross-platform play, but a live invitation test is still needed for step-by-step guidance.
What did Buddy System add?
Update 1.2 added proximity chat, revives, trading, emotes, and two characters.