Survival mechanics

The Subnautica franchise is built around underwater survival. Players manage oxygen, food, water, and health while exploring, gathering materials, and building. Subnautica 2 retains the core systems from Subnautica and Below Zero while introducing new systems and reworking several old ones.

Oxygen

Oxygen management is the franchise's defining mechanic. Players have a limited air supply that depletes underwater. Shallow biomes can be explored immediately; mid-depth zones require upgraded tanks and a vehicle; the deepest areas demand specialized equipment. Running out of oxygen is one of the most common causes of death.

Food and water

Players must eat and drink. In the original Subnautica, food came from cooking fish and harvesting plants; water was fabricated from bladderfish or salt and coral. Below Zero added caloric expenditure from cold. No specific changes to the food/water system have been confirmed for Subnautica 2.

Health and depth

Health depletes from creature attacks, environmental hazards, drowning, and falling. Depth acts as a progression gate. Vehicles and equipment have maximum depth ratings, creating a natural gear treadmill toward deeper biomes with rarer resources.

No weapons

The Subnautica franchise does not include weapons. Design Lead Anthony Gallegos confirmed for Subnautica 2: "no weapons of any kind." The knife has been replaced by a cutting tool. Leviathans cannot be killed. Creative media producer Scott MacDonald stated: "The point of Subnautica is not to kill everything", players must "learn, evade, and survive."

Changes in Subnautica 2

Starting deep

The game begins with the player's ship crashing into Planet Zezura's ocean depths. The ship's AI directs the pioneer to use an experimental gene-altering machine before being propelled to the surface. This inverts the traditional Subnautica pacing.

Decimal inventory

Resources are stored as fractional quantities (e.g., "0.71 titanium") rather than whole units. Resources appear as concentrated ore chunks on the seafloor instead of breakable rocks that dropped random materials.

Genetic modification

The Biosampler lets players collect biological material from creatures and modify their genetics. Confirmed adaptations include improved diving abilities, night vision, cold resistance, resistance to specific threats, and enhanced swimming speed. The PDA tracks active adaptations.

The Blight

Leaked milestone documents revealed that an ecosystem restoration mechanic from the original development plan was replaced by a new system called "Blight." No details about how Blight works have been publicly shared, but the name suggests an environmental threat that players must contend with rather than a restorative mechanic.

Co-op survival

The addition of co-op introduces shared survival dynamics. Bases require collective power management for up to four players. The Dive Elevator enables coordinated resource runs. Team members can rescue each other in emergencies.

Narrative integration

The story targets approximately 15 hours, separate from exploration time. PDA entries reference characters from previous games, including Ryley Robinson and Marguerit Maida.