Tundra

Lore & Background

In the world of Oxygen Not Included, the Tundra is the planet's frozen skin—a thin, brittle shell of ice, snow, and cold stone that separates the vacuum of space from the warmer geology buried below. It is a place of stillness and silence, where the wind carries nothing but crystalline grit and the ground groans under the weight of ancient frost. For the Duplicants who crash-land here, it is simultaneously a refuge and a threat: the surface atmosphere allows them to breathe without a helmet, yet the ambient cold saps their energy and forces them to burn precious fuel just to stay alive.

The Tundra's geology is relatively simple compared to the mineral-rich layers beneath. Its strata are dominated by ice, snow, and basic rock, with only modest deposits of the materials needed for advanced construction. This scarcity is by design of the narrative: the colony must look downward, dig deeper, and trade the safety of breathable air for the warmth and wealth of the Desert and Cavern biomes. The Tundra thus serves as both tutorial ground and narrative threshold—the last place Duplicants feel truly 'outside' before they commit to the subterranean life that defines their story.

Fans often describe the Tundra as the emotional anchor of the game. It is where the first Duplicant shivers in the snow, where the first heater is awkwardly placed, and where the colony's fragile sense of home is built from ice blocks and stubborn will. Its cold is not merely a mechanical challenge; it is the atmosphere of the story's opening chapter, the quiet before the furnace roars to life.

In Their Own Story

The wind had no name up here, only a sound—a long, thin whistle threading between the ice pillars. Duplicant 7 pressed a gloved hand against the frozen ground and felt the planet's cold seep through the rubber, patient as a tide. Below, the colony hummed: the low thrum of a heater, the soft clink of a water pipe cycling, the muffled murmur of three others huddled under a blanket of woven fabric. Above, the sky was a flat, featureless grey, and the snow kept falling, patient and indifferent, covering every new brick, every new vent, every small act of defiance against the cold. 7 exhaled. The breath bloomed white and vanished. Somewhere far below, in the warm dark, the desert waited. But tonight, the Tundra held them. Tonight, that was enough.

Reader's Guide

Position in the cross-section: The Tundra occupies the topmost band of the map, containing the surface level and extending downward until it meets the Desert biome. It is the layer where the colony's starting position is located, typically a few tiles below the surface.

Physical properties: Ambient temperatures in the Tundra are below freezing, generally in the range of roughly -10 °C or lower depending on depth within the layer. At the surface, pressure is 1 atm with a breathable atmosphere (nitrogen and oxygen). Deeper within the Tundra, the atmosphere is absent, so Duplicants require a gas source or a sealed habitat. The biome is visually characterized by blue-white ice, white snow, and pale grey rock.

Yields: The primary harvestable resources are ice (which can be melted into water) and snow. Basic rock is also present for construction. The Tundra is notably poor in metals, gems, and other advanced materials—those are found in the Desert, Cavern, and Molten Rock biomes below. Ice is the colony's most important early-game water source.

Hazards: The chief danger is cold. Duplicants exposed to Tundra temperatures without adequate heating will suffer reduced efficiency and, if left unprotected, will eventually freeze. The lack of a breathable atmosphere below the surface means unsealed areas will suffocate Duplicants. Additionally, the Tundra's limited resource variety means the colony cannot sustain itself here long-term without digging deeper.

Did You Know?

• The Tundra is the only biome in the game where snow and ice are found in natural abundance across the surface layer.
• New colonies begin their story in the Tundra, making it the first biome every player encounters and the one most associated with the early-game survival loop.
• Ice harvested in the Tundra is a primary early source of water, since the colony has not yet reached the deeper aquifers and rock formations that yield liquid water.
• The Tundra's surface is the only location in the cross-section where a natural, breathable atmosphere exists without any Duplicant-built gas source.