Jungle

Lore & Background

The Jungle biome is a relic of the planet's ancient biosphere, a place where the crust still remembers what it was like to be green. Unlike the sterile metallic tunnels Duplicants carve through the rock, the Jungle is soft, damp, and alive. Trees with broad canopies push through fissures in the stone, their roots threading through soil that has not seen a Duplicant boot for millennia. The air here is thick and warm, carrying the faint sweetness of decomposing leaves and the slow exhale of photosynthesizing foliage.

Colonists who first breach into the Jungle from the upper grasslands often remark on the sudden shift in pressure and temperature. The walls are no longer bare rock but are draped in moss, lichen, and creeping vines. Small lizards dart between the roots, and the canopy above filters the dim ambient light into dappled green. It is, by the standards of the rest of the cross-section, almost alien in its abundance. The trees are not merely decoration; they are the biome's economic engine, yielding wood that can be processed into planks, fuel, and organic compounds essential for a growing colony's infrastructure.

Yet the Jungle's warmth is a double-edged blade. Enclosed pockets of jungle air, sealed off by Duplicant construction, can trap heat and CO2 at levels that sicken or kill. The humidity accelerates corrosion on exposed metal, and the organic matter, left unmanaged, rots and releases methane. The Jungle gives generously to those who respect its rhythms and punishes those who treat it as just another vein to strip.

In Their Own Story

The air tasted of wet earth and green things. Kira pressed her gloved hand against the trunk and felt it give slightly, warm and almost soft, like the hide of something breathing. Around her, the canopy stretched in every direction—up, down, sideways—until the boundary between ceiling and floor dissolved into a tangle of roots and leaves. A lizard the color of rusted copper flicked its tongue at her shadow and vanished into the undergrowth.

She pulled her axe free and set it against the bark. The first strike sent a shower of pale chips spiraling into the humid air. The second. The third. The tree groaned—a low, wooden sound that was not quite a sound at all, more a vibration in her teeth. It fell with a wet thud that sent a pulse of warm air rolling through the undergrowth, carrying the scent of sap and something older, something that had been rotting and regrowing for longer than her colony had existed.

Kira wiped her forehead. The thermometer on her wrist read warm. Too warm. She'd need to vent this pocket before the CO2 climbed. But not yet. Not while the wood was still fresh and the axe still sang in her hands. She set it against the next trunk and smiled.

Reader's Guide

The Jungle occupies the upper portion of the cross-section, nestled just below the surface grasslands and above the deeper cave systems. It is immediately recognizable by its dense tree cover, mossy walls, and the warm, humid air that distinguishes it from the cooler, drier rock of the surrounding biomes.

Temperature in the Jungle runs warm—noticeably higher than the grasslands above and the caves below. If you seal a jungle pocket without adequate ventilation, heat and CO2 will accumulate quickly. The gas composition skews toward elevated CO2 and reduced O2 compared to the surface, a byproduct of dense respiration and decomposition. Duplicants working in unventilated jungle sections will begin to suffer from CO2 poisoning and heat stress within minutes.

The primary yield is wood, harvested by chopping the large trees that populate the biome. Wood can be processed into planks for construction, burned as fuel in furnaces and fireplaces, or broken down into organic compounds for other uses. Smaller organic matter—leaves, moss, and plant debris—can also be collected and processed, though the trees are the economic backbone.

Hazards include heat buildup in enclosed sections, CO2 accumulation, humidity-driven corrosion on exposed metal surfaces, and the presence of small fauna (lizards) that can scatter into work areas. Rotten organic matter left unmanaged will release methane, creating a secondary gas hazard. Always ensure active ventilation and heat exhaust when colonizing jungle pockets, and clear dead plant matter regularly to prevent methane pockets from forming near living quarters.

Did You Know?

• The Jungle's trees are one of the few renewable wood sources in the upper cross-section, making them critical for early-game construction before Duplicants can access deeper mineral deposits.
• The humid, CO2-rich air of the Jungle means that simply walking through an unventilated jungle pocket can begin to deplete a Duplicant's O2 and raise their CO2 levels, even without any active heat source nearby.
• The small lizards found in the Jungle are among the few passive fauna in the upper biomes; they do not attack Duplicants but will scatter and hide when a colonist enters their area.
• Organic matter in the Jungle, if left to decompose in a sealed space, will produce methane gas, turning a seemingly harmless pocket of leaves into a potential explosion hazard.