Black Sun, White Moon

The world is divided into three major realms:
1.) our reality, the banal world
2.) The Dreamscape: a vast mythical world, built up in part through the dreams of humanity and in part by beings of the dreamscape. This world is like the "twilight" in night watch to some extent, but also like the land of Faerie from Stardust, or the umbra, or like the land of the neverending story. I will still have to do a lot of work to define this.
3.) The Aether: a sub-dreamscape, so to speak, full of vast, uncontrollable energies and dire, malevolent entities that seek the destruction of all things.

The three realms can be compared to three sheets of fabric layered over one another: at certain "lynchpin" points, they are fixed, and these areas have a firm location in more than one realm. Other than this, sections can slide past one another, allowing those with the proper skill to "flex" reality, or dreams, to allow speed of thought transport among other things.

Characters can represent one of the following "races":

1.) Pathfinders: humans who have learned to manipulate the dreamscape, and to draw power from it.
2.) Avatars: Dreamscape natives, who are able to wield the power of the dreamscape in the real world.
3.) Daemons: Beings of the Aether...this would not typically make a good character class.
4.) Vassals: Golems (constructs made by one of the other classes), mortals, and lesser creatures of the dreamscape realm in service to 1-3.

Pathfinders, Avatars, and a few select Daemons (notably the dragons) are organized in the following ways. Some of the organizational levels are mutually exclusive, some are not.

1.) Houses: The hefty political institutions of the dreamscape, these are akin to the noble houses of the 17th through early 20th century (Hapsburgs, Borgheses, etc.). They are highly hierarchical, with vast resources and extensive, century-spanning plans and policies.
2.) Orders: In general, membership in a House and in an Order are mutually exclusive. Orders form to accomplish some specific task (such as Ignatius' Dragon Crusade of the 13th century, aimed at clearing the dreamscape of dragons): usually those most affected by the circumstances form the core of an order (House Ignus, which was roughly 80% destroyed by dragons, began the order of Ignatius, still active today). Both orders and houses will brook no mixed loyalties.
3.) Companies: Another "exclusive" organization type, companies are small (tens to a few hundred members at most, including vassals) compared to orders or houses. Typically, they engage in little politicking, have a loose organizational structure, and are organized around some poorly defined ideal or principle

Nonexclusive organizations:
1.) Guilds: spanning houses, orders, and companies, those Dreamwalkers that engage in similar trades often band together to share skills, compete for business, or fix prices. Guilds claim to be apolitical, but this is rarely the case, much to the chagrin of many houses and orders. However, the guild structure, much like fellowships, is so ingrained in the Dreamscape that none have been able to threaten it.
2.) Fellowships: it is tradition that young or new members of houses, orders, or companies join into small bands with those from outside their principal organization, as a way to gain experience in the ways of the realms. Some of the stricter orders and houses frown on this, but maintain the tradition nonetheless.