Meanarin is covered in a mysterious mist which creates phantasms according to the wills of those within it. It is a world of dreams, illusions, nightmares, and utopias. The world’s theme is “the lands of faerie”.
The mists of Meanarin are potent, but not all-powerful. The illusions they create are potent enough that people can really interact with them. You could walk across a phantasmal bridge or warm yourself at a phantasmal fire. That said, the results of willing the mists to do something always results in an illusion, not reality. Raising someone from the dead only results in a mist-powered phantom of that person, for example.
The rulers of the world are the most potent of dreamers. They can weave castles, creatures, landscapes, even whole populations. The geography of the world is as ever-changing as its politics. To combat this, “anchor roads” have been set on the planet, lit by lanterns which repel the mist. When one is on an anchor road, they can feel relatively safe from the planet’s many dangers.