The Biomod system is Subnautica 2's primary character progression mechanic, replacing the traditional skill tree found in many survival games. Instead of spending experience points on static upgrades, players install biological modifications (biomods) into passive slots on their character. These biomods are researched at Biolabs scattered across the map, and each provides a distinct passive bonus that enhances the player's capabilities in specific areas such as oxygen capacity, swimming speed, predator avoidance, or scanning efficiency.
The system is designed to encourage exploration and reward players who venture into diverse biomes. Each Biolab focuses on a specific category of biomods, and the research missions at each lab require scanning creatures and collecting data from the surrounding biome. This means that to unlock the full range of biomods, players must explore multiple biomes rather than staying in a single safe area. The system also creates natural progression gates, as some Biolabs are located in deeper or more dangerous biomes that require better equipment to reach.
Each player starts with 2 passive biomod slots, and additional slots are unlocked by completing Biolab research missions. The maximum number of passive slots is 6, meaning players must choose which biomods to equip based on their current objectives. This creates meaningful build diversity: a player preparing for a deep exploration mission might equip Oxygen Plus, Pressure Resistance, and Camouflage, while a player focused on resource gathering might prefer Scanning Range, Swimming Speed, and Resource Detection.
The EA 1.1 Adaptive Measures update introduced significant improvements to the biomod system. The most notable change is the smoothing of biomod transitions, which eliminates the brief gameplay interruption that previously occurred when switching equipped biomods. The update also expanded the number of Biolabs from 4 to 6, giving players more options for biomod research and passive slot unlocks. Additionally, several biomods were rebalanced to make them more competitive, giving players more viable build options rather than a single dominant meta.
What is the Biomod System and How It Works
The Biomod system is Subnautica 2's primary character progression mechanic, replacing the traditional skill tree found in many survival games. Instead of spending experience points on static upgrades, players install biological modifications (biomods) into passive slots on their character. These biomods are researched at Biolabs scattered across the map, and each provides a distinct passive bonus that enhances the player's capabilities in specific areas such as oxygen capacity, swimming speed, predator avoidance, or scanning efficiency.
The system is designed to encourage exploration and reward players who venture into diverse biomes. Each Biolab focuses on a specific category of biomods, and the research missions at each lab require scanning creatures and collecting data from the surrounding biome. This means that to unlock the full range of biomods, players must explore multiple biomes rather than staying in a single safe area. The system also creates natural progression gates, as some Biolabs are located in deeper or more dangerous biomes that require better equipment to reach.
Each player starts with 2 passive biomod slots, and additional slots are unlocked by completing Biolab research missions. The maximum number of passive slots is 6, meaning players must choose which biomods to equip based on their current objectives. This creates meaningful build diversity: a player preparing for a deep exploration mission might equip Oxygen Plus, Pressure Resistance, and Camouflage, while a player focused on resource gathering might prefer Scanning Range, Swimming Speed, and Resource Detection.
The EA 1.1 Adaptive Measures update introduced significant improvements to the biomod system. The most notable change is the smoothing of biomod transitions, which eliminates the brief gameplay interruption that previously occurred when switching equipped biomods. The update also expanded the number of Biolabs from 4 to 6, giving players more options for biomod research and passive slot unlocks. Additionally, several biomods were rebalanced to make them more competitive, giving players more viable build options rather than a single dominant meta.
All 6 Biolab Locations After EA 1.1 Update
After the EA 1.1 Adaptive Measures update, Subnautica 2 features 6 Biolabs across the map. Each Biolab is a specialized research facility where players can complete missions to unlock new biomods and passive slots. The original 4 Biolabs from the early access launch are supplemented by 2 new locations in the Coral Gardens and Axum Ruins, providing a more distributed progression path that encourages exploration of the full map.
Biolab 1 - Safe Shallows Biolab: Located in the starting biome at approximately 20 meters depth, this is the first Biolab most players encounter. It focuses on basic survival biomods including Oxygen Plus (Tier 1) and Swimming Speed (Tier 1). The research mission requires scanning 10 common creatures in the Safe Shallows. This Biolab is accessible from the start of the game with no special equipment required.
Biolab 2 - Grassy Plateaus Biolab: Found at approximately 50 meters depth in the southern region of the map. This lab specializes in defensive biomods such as Health Boost and Damage Resistance. The research mission involves scanning 12 creatures native to the Grassy Plateaus, including Stalkers and Sand Sharks. A Seamoth or better vehicle is recommended for efficient travel to this location.
Biolab 3 - Karakorum Metal Farms Biolab: Located at approximately 150 meters depth in the northern region. This lab focuses on resource-gathering biomods including Scanning Range and Resource Detection. The research mission requires scanning 15 creatures and collecting 5 mineral samples from the surrounding area. A vehicle with at least 200-meter depth capability is needed to reach this Biolab safely.
Biolab 4 - Deep Trench Biolab: Found at approximately 300 meters depth in a deep trench in the western region. This lab specializes in deep exploration biomods such as Pressure Resistance and Oxygen Plus (Tier 2). The research mission is the most challenging of the original four, requiring scans of 20 deep-sea creatures including several dangerous predators. A Prawn Suit or deep-rated Tadpole is recommended for accessing this Biolab safely. Biolab 5 - Coral Gardens Biolab (New): Added in EA 1.1, located at approximately 100 meters depth in the eastern region. Focuses on stealth and defensive biomods including Camouflage and Predator Deterrence. Biolab 6 - Axum Ruins Biolab (New): Also added in EA 1.1, located at approximately 250 meters depth in the western ruins area. Specializes in exploration and efficiency biomods including Scan Speed Boost and Inventory Weight Reduction.
How to Unlock Passive Biomod Slots
Passive biomod slots are the core of Subnautica 2's character customization system, and unlocking all 6 available slots is essential for maximizing your character's potential. Each player begins the game with 2 passive slots, and the remaining 4 are unlocked through Biolab research missions. The slot unlock progression is tied to specific Biolabs, meaning you cannot unlock all slots from a single location; you must visit and complete missions at multiple Biolabs to reach the maximum.
The first additional slot (slot 3) is unlocked by completing the research mission at the Safe Shallows Biolab. This is the easiest mission in the game, requiring only 10 creature scans in the starting biome. Most players will unlock this slot within the first 2-3 hours of gameplay. The second additional slot (slot 4) comes from the Grassy Plateaus Biolab, requiring 12 creature scans in a slightly more dangerous biome. This slot is typically unlocked in the early-to-mid game.
The third additional slot (slot 5) is unlocked at the Coral Gardens Biolab, one of the two new Biolabs added in the EA 1.1 update. The research mission here requires scanning 15 creatures and is moderately challenging due to the presence of mid-tier predators in the Coral Gardens biome. The fourth and final additional slot (slot 6) comes from the Deep Trench Biolab, which has the most demanding research mission in the game: 20 creature scans in a deep, predator-heavy environment.
It is worth noting that the Axum Ruins and Karakorum Metal Farms Biolabs do not directly unlock passive slots; instead, they unlock the biomod blueprints that you can install in those slots. This design ensures that players must visit all 6 Biolabs to fully maximize their character, as the slot unlocks and biomod blueprints are distributed across different locations. Plan your exploration routes to visit Biolabs in order of difficulty, starting with the Safe Shallows and Grassy Plateaus labs before venturing into the deeper and more dangerous locations.
Best Biomods for Different Playstyles
With 6 passive slots available and a wide range of biomods to choose from, selecting the right combination for your playstyle is crucial for survival and efficiency in Subnautica 2. The optimal biomod loadout depends on your current objectives, the biomes you plan to explore, and whether you are playing solo or in co-op. Below are recommended loadouts for the four most common playstyles.
Deep Exploration Build: For players venturing into the deepest biomes (200+ meters), the essential biomods are Oxygen Plus (Tier 2), Pressure Resistance, and Camouflage. Oxygen Plus extends your base oxygen capacity by 50%, giving you more time to explore before needing to surface or find an air source. Pressure Resistance reduces the rate at which your health depletes when exceeding your depth limit, providing a safety margin for emergency situations. Camouflage reduces predator detection range, which is critical in deep biomes where Leviathans patrol. Fill the remaining slots with Health Boost and Scan Speed Boost for survivability and data collection efficiency.
Resource Gathering Build: For players focused on farming materials for crafting and base building, the recommended loadout is Resource Detection, Scanning Range, Swimming Speed, and Inventory Weight Reduction. Resource Detection highlights nearby mineral deposits on your HUD, while Scanning Range increases the effective range of your scanner, allowing you to identify resources from a greater distance. Swimming Speed reduces travel time between farming nodes, and Inventory Weight Reduction lets you carry more materials before becoming encumbered. The remaining slots can be used for Oxygen Plus to extend dive time and Camouflage for safety in predator-heavy farming zones.
Combat and Rescue Build: For players who frequently engage predators or perform vehicle rescues in dangerous waters, the ideal loadout includes Health Boost, Damage Resistance, Camouflage, and Swimming Speed. Health Boost increases your maximum health by 50 hit points, while Damage Resistance reduces all incoming damage by 15%. Camouflage is essential for approaching damaged vehicles without triggering predator attacks, and Swimming Speed provides the mobility needed to escape dangerous situations quickly. The remaining slots should be filled with Oxygen Plus for extended operations and Scanning Range for situational awareness.
Co-op Support Build: In multiplayer sessions, one player can specialize in a support role with the following loadout: Scanning Range, Scan Speed Boost, Resource Detection, and Health Boost. This player acts as the team's scout and information gatherer, identifying points of interest, scanning creatures for the team's research progress, and marking resource deposits. The support build complements the combat and gathering builds used by other team members, creating a well-rounded party that can handle any situation the game throws at them.