I still haven't fully fleshed out the Houses yet, but I know that there will be a House that rules the north, one that rules the south, and one that rules the east.

Dragons with noble blood must reside within their own House. For instance the son of the Lord of Nocturne will have to reside in Nocturne, at least originally. The rest can defect and pledge alliegences to other Houses.

Dragons, in their feral forms, are about the size and length of a school bus. In their human forms, they're able to read, write, dance, forge, etc. 

Humans will be playable and will have medieval level technology and a medieval form of living.

No one flew over the Clouded Sea mostly because of fear; everyone who has flown across it has never come back, thus they don't know what's across it.

Wyverns, chimeras, sirens, and even other dragons can pose a threat to dragons.

Dragons live hundreds of years. But their physical appearance stops changing when they start to look like they're in their mid 30s.

Dragons have writing due to be able to write in their human forms.

Dragons cannot cast magic and their only type of breath is fire.