The Underground Desert is a biome located directly underneath a Desert biome. On the 电脑版 the Desert above may generate different features which informs that the Underground Desert is underneath, whereas on the 主机版和 移动版 the Desert will always generate a large 'antlion funnel' which leads down into the Underground Desert. See Surface Desert below for details. The Desert/Underground Desert pair will always generate on the same side of the world the Jungle is on.
The structure of the Underground Desert resembles that of a real-world ant hive, featuring numerous small caves mainly composed of Sandstone Blocks and Hardened Sand Blocks, which are connected in varying degree. It is very large when fully explored, rivaling even the Dungeon in size, and is always either circular or oval in shape. The Underground Desert is inhabited by many types of Antlion enemies and is also riddled with traps, making it a challenge to navigate.
The Underground Desert becomes significantly more challenging in Hardmode. Along with harder enemies, the Underground Desert is extremely vulnerable to conversion by Corruption, Crimson, or Hallow due to Sand, Hardened Sand, and Sandstone all being susceptible to conversion. Conversion further strengthens the Underground Desert's enemies, and in Corruption and Crimson Underground Deserts, causes the spawn of Desert Spirits.
On the 电脑版, the Desert above the Underground Desert may generate with various surface features, including one or more Oasis mini-biomes, or one of several types of entrances. There is a 1 in 3 (33.33%) chance that a world's main Desert will contain one of the various types of entrance. These can assist in locating and accessing the Underground Desert from the surface. The presence of an Oasis does not indicate where the Underground Desert is, as the Oasis mini-biomes can generate atop any of the world's Deserts, regardless of which of them contains the Underground Desert biome.
On all versions, it is possible for one or more Pyramids to generate in the main Desert. When this happens, the Pyramid will often extend somewhat into the Underground Desert, and thus its tunnel can provide another easy means of entry. As with the 绿洲 mini-biome, Pyramids can generate in any of the world's Deserts, regardless of where the Underground Desert is located, and so their presence does not guarantee that the Underground Desert is below.
See Desert for more information about the surface entrances to the Underground Desert.
- While artificial Underground Deserts can be created by placing their respective blocks, no unique enemies will ever spawn due to lack of specialized back walls. It shares this trait with the Dungeon. (While it is possible to craft Sandstone Walls and Hardened Sand Walls via the use of Ecto Mist as of 1.4, these walls are considered "safe" and will prevent enemy spawns.
- On the 电脑版, the border between the Underground Desert and the Caverns often feature pools of lava much closer of the surface than where lava would normally generate.
- In the real world, larval antlions create funnel-like pits in the ground and fling sand at prey that pass by. The funnel and burrow entrance types to the Underground Desert are presumably inspired by this.
- 电脑版 220.127.116.11：
- Added Sandstone Chests in world generation.
- Generation changed to make the biome go to varying depths.
- Introduced a brand new music track for the Underground Desert.
- Lava now spawns at lower levels towards the edge of the biome.
- The Desert above the Underground Desert may now generate other features than the funnel entrance, and the funnel design has also changed.
- 主机版 1.0.933.1：引入。（）
- 主机版 1.0.750.0：引入。（）
- 移动版 18.104.22.168：引入。