Tile

A tile is the fundamental building block of Oxygen Not Included maps, forming the solid blocks that make up biomes, constructed environments, and the boundaries that contain atmospheres and liquids. Each tile occupies a 1x1 cell and defines whether that cell is filled with a material (rock, metal, regolith, ice, etc.), is empty space (vacuum), or contains constructed floor/wall material placed by the player. Natural tiles come from biomes and carry the composition, temperature, mass and physical properties of their source material; constructed tiles are created when duplicants build a Floor, Wall, or Tile from a chosen material.

Tiles determine traversal, structural support, heat transfer, gas and liquid flow, and what materials can be mined or liquefied. Natural tiles often provide resources (ore, raw materials, organic matter) when mined and may off-gas or decay in specific biomes. Constructed tiles act as barriers to gases and liquids and can be used to create rooms that retain atmosphere and heat; using insulated or high-thermal-mass materials changes how heat moves through the environment.

Tiles interact with nearly every other game system and require attention in base design and exploration:

• Biomes are collections of natural tiles with distinct material mixes and temperatures; each biome’s tiles supply the early- and late-game resources typical to that biome. Examples include Sandstone, Forest, Tundra, Jungle, Magma, Marsh, Ocean, Oily, Rust, Space, and many specialized biomes added by DLC and packs (Swampy, Aquatic, Metallic, Niobium, Radioactive, Regolith, Wasteland, Ice Cave, Cool Pool, Nectar, Garden, Feather, Wetlands, etc.). The tile composition of a biome dictates available ores, plants, critters, and thermal behavior.
• Mining a tile removes its mass and yields resource items if the material is mineable. Some biomes include liquefiable or consumable tiles that disappear over time (for example, tiles that off-gas), which can open unexpected holes and spill liquids.
• Tiles conduct heat according to their material’s thermal conductivity and specific heat; choice of building material for constructed tiles affects room temperature control and insulation. Vacuum/space (open background) prevents heat dissipation through the background, so sealing with tiles or drywalls is necessary to contain air and manage heat.
• Certain world features and events interact with tiles: Meteor Showers deposit materials onto tiles, magma biomes contain tiles that cannot be destroyed, and some DLC biomes include tiles that freeze or sublimate at environmental extremes.
• Liquids and gases flow around and through the map according to tile placement; draining, flooding, or pressurizing areas depends on tile layout. Tiles that are removed by off-gassing or that contain pockets of liquid require planning to avoid sudden breaches.

Practical considerations when managing tiles:

• Use durable, high-melting-point materials for tiles exposed to extreme heat (magma, vents) and insulated materials where thermal isolation is important.
• Anticipate tile loss in biomes or rooms where off-gassing consumes natural tiles; reinforce floors and install barriers to prevent accidental flooding or loss of atmosphere.
• When mining, plan for falling liquids and gases from overlying tiles; shore up ceilings or dig from the side when redirecting volatile pockets.
• Seal the map with constructed tiles or drywalls to retain atmosphere and prevent heat loss to space; different tiles and materials change whether heat will efficiently dissipate or be retained.
• Exploit biome-specific tiles for their resources (ores, organics, liquefiable masses) but respect their thermal and decay properties to avoid destabilizing the base.

Tiles are the core substrate of both natural world generation and player construction. Understanding tile materials and behaviors is essential for resource extraction, base containment, temperature control, and safe exploration of biomes across the asteroid.