Planet Crafter Underground Base Guide: The Underground Pod on Skeo

The Planet Crafter underground base arrived with update v2.102 "Skeo" on September 1, 2026. The module that makes it possible, listed in the changelog as the "Underground pod" and in the game data as the Underground living compartment, unlocks on the new moon Skeo. It puts a ladder into the ground, and at the bottom you build a full base below the surface.

This guide keeps three things apart: what the official changelog confirms, what only comes from a fan database that reads the game files, and which questions about the mechanics are simply still open.

🗺️ What the Underground pod is, and what it isn't

Miju Games writes in the v2.102 changelog: "Added new 'Underground pod' allowing to build a base underground (unlocks on Skeo)". That's the complete official statement on this building piece: a new module that allows underground building, unlocked on Skeo. Nothing more.

It's worth separating it from two things that sound similar in the game. The bunkers on Prime are fixed locations with loot, golden statuettes and messages from earlier settlers. You find them, you don't build them. According to a fan wiki, nine of them are spread across Prime, including in the dune desert, the meteor crater and the wasteland.

The second is the old bunker trick. Since 2022 a guide has been going around where you clip through the terrain by abusing the option for freeing a stuck player and place normal living compartments down there. The guide itself says this was "not intended by the developers", with fall damage, a jetpack that cuts out and water behaving strangely underground. The new module replaces that workaround with a regular building piece for your Planet Crafter underground base.

🔓 How to unlock the Planet Crafter underground base

The unlock depends on Skeo, and Skeo depends on your progress. You have to fully terraform a starting planet (Prime, Toxicity, Humble or Selenea), then build the Extraction platform and the Interplanetary travel rocket. Skeo is explicitly not a starting planet. The full route is in our guide to the moon Skeo.

You no longer need the development branch for this. Skeo has been in the regular game since September 1, 2026, free and at the same time on Steam, PS5, Xbox Series X|S and GOG. If you're still on the test branch, just set it back to "None" in the Steam properties.

On Skeo itself, the fan database planetcrafter.th.gl, which reads the game files, lists the Herds stage as the requirement, a terraformation stage tied to herd animals. The practical point: it's not enough to land on Skeo. There's a stage threshold on top.

⚒️ Recipe and cost compared

The official changelog doesn't list ingredients. The list below comes from the same fan database, so it's a community figure, not a developer statement. The site reads the game files, but there's no official confirmation:

The gap is the real point. A normal living compartment costs two ores from your first hour of play. The underground module wants four refined materials at once, including Blazar Quartz and Explosive. It's not something you place on the side. It's a deliberate investment, and it explains why the module unlocks so late. How to dig for resources on the moon is covered in our guide to amber on Skeo.

🪜 How the underground base works

The module description is short and still explains the whole mechanic: "Creates a ladder to an underground compartment from which you can build an underground base". So it isn't a room you drop underground. It's an entrance.

You place it on the surface, it creates the shaft, and a first compartment hangs below it. From that compartment you keep building with the familiar modules: corridors, big living compartments, machine rooms. Internally, the game files the piece under the ID build_PodUnderground, in the same family as all other living compartments.

For oxygen and pressure, the same logic very likely applies as on the surface: according to a fan wiki, living compartments produce oxygen even without power once the base is sealed. Nobody has confirmed that for the underground module, though. You'll have to run power down from the surface anyway, because solar panels get no light underground. If your grid needs more headroom, our guide to all Planet Crafter fuses helps.

The same update also added a new interior lamp, also unlocked on Skeo. Underground that's not decoration. It's the difference between a usable base and a pitch-black one. Miju Games also fixed the environment flickering when moving between compartments, a detail you notice most in nested interiors.

💡 Pros and cons compared to a surface base

• Space without terrain trouble. Underground, you decide the floor area, not the slope. Anyone who has placed machines on uneven ground on Prime knows what that's worth.
• No conflict with the water level. Rising water is a real building problem later in terraforming. The underground base sidesteps the question of whether your spot floods later, at least as long as you dig in deep enough and not under a lake.
• Looks and order. Production below, living space and domes above: that untangles a base that has grown over time.
• Expensive. Four refined materials per entrance. Spreading several shafts across the map costs serious resources.
• Available late. You need a fully terraformed planet, the trip to Skeo and the right terraformation stage there. It's no plan for the start of a run.
• No replacement for the dome. Terraforming machines that depend on area and plant growth still belong up top. Where the good surface spots are is covered in our guide to the best Planet Crafter base locations.

⚠️ Common mistakes with your first shaft

The most common mistake is the expectation: many players look for a ready-made cave on Skeo and miss that the entrance has to be built. The second is material planning. If you fly to Skeo without Blazar Quartz and Explosive in your bags, you're stuck with a blueprint you can't build.

The third is the order: unlock the recipe through the terraformation stage first, then build. And building underwater is a separate mechanic from building underground. The two get mixed up a lot.

📊 What's still open about the underground base

Being honest matters more here than a neat table of numbers. These points are not confirmed and will be added once a verifiable source exists: the module's power use, its oxygen output, how deep the shaft goes, how many compartments you can attach, and whether the module can be deconstructed normally.

Also open: whether you can place the module on Prime, Humble, Toxicity or Selenea after unlocking it, or only on Skeo. The changelog says "unlocks on Skeo". That's a statement about where it unlocks, not necessarily about where you can build it. Anyone who gives you a firm answer today is guessing.

At the time of our last check, Miju Games hadn't published anything beyond the changelog line about the module.

❓ FAQ about the Planet Crafter underground base

Are the Underground pod and the Underground living compartment the same thing?

Yes. The official changelog calls it "Underground pod", while the fan database planetcrafter.th.gl lists it as "Underground living compartment". Both mean the same building piece with the internal ID build_PodUnderground.

Where does the underground module unlock?

On the moon Skeo. According to the fan database, the unlock there also depends on the Herds stage. The official changelog only names Skeo and no stage, so the stage requirement is a community figure.

What does the underground module cost?

According to the fan database, 2x Osmium Rod, 1x Super Alloy Rod, 3x Explosive and 3x Blazar Quartz. Miju Games hasn't published an ingredient list. For comparison, a normal living compartment costs 2x Iron and 1x Titanium.

Do I need extra oxygen underground?

That's not confirmed for this module. A fan wiki notes that regular living compartments produce oxygen even without power once the base is sealed. Whether the underground module behaves the same way hasn't been documented by the developer.

Can I build underground with friends?

In co-op, yes. Across platforms, no. The Planet Crafter has no crossplay: multiplayer only works within the same console family, and Steam players can't play with console players. Details in our article on Planet Crafter crossplay.

Is it the same as the bunkers on Prime?

No. The bunkers are fixed locations with loot that you enter through hidden ladders. The underground module is a building piece you place yourself, and it opens your own shaft.

As of October 8, 2026 (version v2.102). Sources: the official Steam announcement by Miju Games for the Skeo launch on September 1, 2026 with the full v2.102 changelog. In addition, the game-data fan site planetcrafter.th.gl for recipe, ID, names and unlock stage, and the Planet Crafter fan wiki for bunkers and living compartment costs.

There is no official Planet Crafter wiki; all wiki information comes from fan projects. Community figures not confirmed by the developer: the recipe, the Herds stage requirement, the oxygen behavior of living compartments and the bunker locations. Power use, shaft depth, deconstruction and building outside Skeo are unconfirmed.