An overview of layers as they may appear on a medium-size map. Note that in-game, the background for Underground and Cavern will display some depth after the layer has actually begun.
A world in Terraria is divided into five layers, each appearing at different depths, or elevations. Each layer has its own characteristics. Most layers contain multiple biomes.
Depth can be determined via a Depth Meter or any of its derivative accessories:
- On the
PC version of the game, depth is measured in feet, with one tile equaling two feet. - On the
Console version, depth is measured in meters, with two tiles equaling one meter.
The Depth Meter numbers feet or meters above Level Surface, then feet or meters below Level Surface. Each reading includes a layer name: Space, Surface, Level Surface, Underground, Caverns, and Underworld. The range of numbers depends on map size and platform. The following table gives numbers for desktop in 1.3.4.4.
| Layer Name | Small World | Medium World | Large World |
|---|---|---|---|
| Space | 560 to 464 | 870 to 610 | 1356 to 683 |
| Surface | 463 to 1 | 609 to 1 | 682 to 1 |
| Level Surface | 0 to 0 | 0 to 0 | 0 to 0 |
| Underground | -1 to -194 | -1 to -422 | -1 to -517 |
| Caverns | -195 to -1350 | -423 to -2242 | -518 to -3276 |
| Underworld | -1351 to -1655 | -2243 to -2562 | -3277 to -3588 |
Space
Space is the topmost layer. It is its own biome and does not contain other biomes. It generally contains no natural structures, although Floating Islands and Living Trees may occasionally extend into it. The Sun, Moon, and stars are visible here against a backdrop that is always black, regardless of the time of day. Gravity is reduced in space, making characters jump higher and fall more slowly. Harpies spawn here, and in Hardmode, Wyverns and Arch Wyverns.
Surface
The surface includes the Forests, Deserts, Corruption, Crimson, Jungle, Snow, Hallowed, and Ocean biomes. Meteorite biomes will usually be found here when they generate. The entrance to the Dungeon is also found here. This layer also usually contains the world's Floating Islands, although these are generally located some distance above the main land mass. A surface Mushroom Biome can be seeded here by players, but will never occur naturally.
Only in the surface layer will regular, Corruption/Crimson and Hallow grass naturally grow and spread (although grass can be planted with seeds or the Staff of Regrowth in other layers, it will not spread). Trees and Corruption/Crimson thorny bushes will only grow in the surface layer. Terrain blocks cover a large amount of the lower surface layer, with Dirt Wall behind them. Areas below the actual terrain surface (areas the player must dig in order to access) are still considered "surface" if they are above 0 feet. The surface layer ends 50 feet below the lowest point of the actual surface. If the usual daytime/nighttime music can be heard while underground, the player is still in the surface layer. Below this layer, the music will change.
Underground
The underground layer contains the same biomes as the surface layer. This layer begins at 0 feet extends downward to around -650ft, depending on world size. It has a unique backdrop that depicts dirt with stones set in it, as well as unique theme music.
Cavern
The cavern layer contains the Underground Snow, Underground Mushroom, and Underground Jungle biomes, which are each located beneath their surface versions. It additionally contains generic cavern features that fill the area between those distinct biomes (see cavern for details on generic cavern features). In Hardmode, the additional Underground Corruption or Underground Crimson, and Underground Hallow, will form. A large section of the Dungeon also extends through this layer.
This layer begins at the -650ft mark, depending on world size, and extends downward to around -3000ft. This layer's backdrop is the same as that of the underground, except the dirt is of a darker hue. It has its own theme music.
Underworld
Usually this layer begins at the -3000ft mark and expands downward to the bottom of the map. Its backdrop is open space with magma pools and pillars. The Underworld is its own biome and does not contain other biomes within it. Lava is abundant here. Any Water that flows into this layer disappears ("evaporates") immediately.
Trivia
- The World Banner depicts world layers.
