Neutronium

Neutronium is an unobtainable element that appears in the world as indestructible, ultra-dense black tiles and as the material of certain prebuilt Ruins structures. It cannot be mined by Duplicants during normal play and functions as an inert, non-heat-transferring substrate that isolates whatever is built from normal thermal behaviour in the game.

Neutronium tiles placed at the map edge or under asteroids are extremely cold at -272.2 °C, while Neutronium used in Ruins buildings is set to 21 °C. Neutronium does not conduct heat because both its specific heat capacity and thermal conductivity are defined as zero. As a result, prefabricated buildings composed of Neutronium do not gain or lose heat from their surroundings, and Neutronium tiles will not change temperature through normal conduction. Two notable exceptions exist: placing a Tempshift Plate adjacent to a Neutronium tile can force heat to be injected into or removed from that tile, and the exhaust plume of a Rocket can raise the temperature of nearby Neutronium during launch.

In debug or sandbox modes Neutronium can be sampled and excavated. The game’s internal mass for a Neutronium tile is 20 t per tile, but sandbox printing limits cause it to display as 9999 kg per tile; using debug excavation will drop 10 t of Neutronium and the dropped item shows a temperature like any other debris. Such dropped Neutronium counts as debris and applies a -10 Decor penalty. When Neutronium’s displayed temperature reaches 10000 K (9726.85 °C) the game will crash instead of simulating molten Neutronium.

Lore entries describe human scientists extracting and refining Neutronium under rare circumstances. The Gravitas researchers theorized that Neutronium forms as an autoimmune reaction of the universe, quarantining foreign materials to prevent temporal contamination. An in-game device description (the Anti Entropy Thermo-Nullifier) indicates that a form called refined neutronium exists and can be used as a power source, implying humans were capable of refining it on rare occasions.

Neutronium is nearly indestructible in normal gameplay. With the “Eye of Sauron!” DLC mechanics enabled, Radbolt Generator fire (radiation particles) can erode Neutronium: 1 unit of radiative particle removes 1 gram of material, so destroying a 20 t tile would require 20,000,000 units of radiative particles — roughly equivalent to a maximum-strength Radbolt Generator firing about 40,000 times. Historically there was a bug allowing Duplicants in the Super Productive state to instant-mine Neutronium, causing skill point overflow; that mining task is now automatically cancelled after update U42-508497. Sweepy bots are capable of interacting with and transporting Neutronium into a Sweepy Dock.

Internally the element is identified as Unobtanium in the game data. Because Neutronium is effectively non-interactive thermally and is otherwise unobtainable by standard means, it primarily serves as a map fixture and lore device rather than a resource for colony development. Practical interactions are limited to special tools, debug/sandbox modes, specific DLC mechanics, and environmental exceptions such as Tempshift Plates and Rocket exhaust.