The Constant, unofficially referred to as Maxwell's World, is the semi-nightmarish parallel world of wilderness where most of the story of Don't Starve, and later Don't Starve Together, takes place. All of the main characters in the game seem to have originated from the "Real World" and were transported here through Maxwell's Door.
The Constant seems to be mostly controlled by "Them". However, after "They" imprisoned Maxwell on the Nightmare Throne, he gained the power to control the world in many ways, such as being able to create many of the world's creatures through an unknown method of experimentation.
The Constant appears to be quite similar to the Real World in various ways. It has a Day-Night cycle, Seasons, Biomes, as well as many creatures which tend to be similar to their "Real World" equivalents such as Crows, Gobblers, and Beefalo which are similar to actual crows, turkeys, and cattle, respectively. On the contrary though, there are also many creatures that are different from their real world counterparts. For example, Pigs have become semi-intelligent bipedal humanoids, capable of basic speech, and seem to be the dominant species on the Surface World as shown by their villages or farms. Rabbits, although a lot like real-life rabbits, have horns as well as their ordinary ears, which cause them to resemble the fictional "jackalopes" of western folklore. Spiders come in many different types, are all larger than real spiders, and live in communal nests.
Even though there are many similar animals, the Constant is home to many unique and, in most cases, frightening creatures. There are flightless and territorial Tallbirds, Summer and Winter Koalefants, and a Winter giant known as the Deerclops. In the Reign of Giants DLC, the Moose, Dragonfly, and Bearger are other seasonal giants encountered in the Constant.
While the maps in Don't Starve mostly take place on islands, it's possible that there is more to the world than just these islands. When Maxwell examines the Moose, he says that he doesn't know what this creature is, only that it's from the North. This makes it possible that there are many other areas in the Constant which are currently unknown to even Maxwell himself, but not necessarily to "Them". According to the Florid Postern's background description, the survivors were scattered across these islands, referred to as dimensions, before the portal connected them. This implies that the islands might actually be separate planes, which are particularly close with each other.
Littered around the islands are Sinkholes, which lead into Caves and the Ruins of a long extinct yet once proud Ancient Civilization of arthropod-like creatures. This mysterious race eventually destroyed themselves, and most of their culture, through the overuse of Nightmare Fuel. It's possible that they were once the dominant species in the dimension until the Shadow Creatures, and eventually Maxwell, gained control of their world.
- The Constant's official name was first revealed in The Forge event, through certain item descriptions.
- According to Rhymes with Play #162, the Constant is a separate dimension from the "hub" mentioned by Battlemaster Pugna.