Agree on a small shared objective
A useful co-op session starts with one objective that every player can state: collect the missing ingredients for a blueprint shown in your current build, test a piece of equipment, or explore a short route with an agreed return point. The goal is an editorial suggestion rather than a required quest sequence.
Record the build on each device and decide who is hosting. Confirm that everyone can join, see the same intended object and recognize the return point before extending the dive. Do not use an old Early Access guide as proof that an ingredient, prompt or save behavior is unchanged.
Voice and trading: verify the result, not only the button
Buddy System added cross-platform proximity voice with always-on, push-to-talk and always-off choices. Distance affects audibility. It also added direct player inventory exchanges. Read the currently displayed bindings and microphone choice rather than assuming a key from another platform.
- Choose a voice mode that everyone is comfortable using.
- Test a short message at close range and at the distance you expect to work.
- Agree on an alternative if distance or device settings make voice unreliable.
- Exchange one low-value item and check both inventories before trading a session-critical item.
An inaudible message can come from range, microphone permissions, an input device or a setting. Changing all of them at once obscures the cause. When troubleshooting, keep the players close and vary one choice.
Know the recovery choice before an emergency
The August update introduced reviving another player before reprinting. Its notes say revived players keep equipment and regain a small amount of oxygen; a downed player can instead choose immediate reprinting at the assigned Biobed. The notes do not establish an exact oxygen quantity or a universally safe rescue distance.
Before leaving, agree on what “return now” means for the group. A second player should not turn one downing into multiple failures by following an unknown route without a return margin. Follow the current prompts and keep any rescue decision conditional on the situation actually shown in the game.
Separate host and joining-player observations
| Field | Host records | Joining player records |
|---|---|---|
| Build / platform | Displayed version and host device. | Displayed version and joining device. |
| Action | Exact object and interaction performed. | What appeared at the same moment. |
| Result | Prompt, inventory or power change. | Prompt, inventory or power change. |
| Repeat | Whether it happens after rejoining. | Whether distance or another object changes it. |
The same patch included multiplayer building and interaction fixes. A developer’s reported fix is useful context; it does not prove that every save is unaffected. Keep a record of a mismatch before rebuilding a base or replacing local data. Use supported save and support procedures on your platform.
Your next-session note
Write one observation, one change and the result you want to compare. The fields stay in this open tab only; download a text copy before leaving. Nothing here reads your game save.
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Sources: review and scope
Sources checked 10 October 2026. Independent, AI-assisted writing checked against the specific references below. The cited update is an August 2026 record, not a claim that it is the latest build. No new in-game test, save synchronization guarantee or exact revive oxygen quantity is claimed.
- Unknown Worlds, 19 August 2026: Early Access 1.2 Buddy System
- Official Subnautica site: current game and support links
Send a correction with the page, source and relevant version or travel date.