From Creatures Wikia
Rooms and doors are the building blocks of metarooms and worlds. A room is a quadrilateral space usually taking the form of a rectangle with straight sides, although in C2 they may have floors of varying height and in C3/DS the top and bottom may be raised or lowered independently of one another.
Despite the name, areas that correspond to one visually contiguous space in the games after C1 - such as the incubator area in C2, the lower levels of the C3 Jungle Terrarium or the lower Norn Meso in DS - are normally composed of multiple rooms linked together. This allows for more natural flow of CAs and provides much more detail and variability in shape than is possible for a single large room, which can have only four sides. Regions in which neither is a factor, such as the C3 Crypt, are usually composed of a single room.
If rooms in C1/C2 are improperly defined, it can result in Black Holes forming.
C3/DS room types
|0||Atmosphere||Heat and light travel well, nutrients and water do not.|
|1||Wooden Walkway||Insulates against heat, but permits water to drip through.|
|2||Concrete Walkway||Less permeable to more CA than a wooden walkway.|
|5||Normal Soil||Fairly permeable to most CA.|
|6||Boggy Soil||Retains more moisture than normal soil.|
|7||Drained Soil||Loses more moisture than normal soil.|
|8||Fresh Water||Restrictive to heat.|
|9||Salt Water||Restrictive to heat.|
|10||Ettin Home||Loses the smell of machinery.|
|This stub could use more information.|