The dragonborn of Vidarr fall into two distinct categories, the draconians and the draconids.
The draconians are a troubled people descended from abominations born of magic rituals that corrupted metallic dragon eggs and produced humanoid dragonspawn. Though draconians are not inherently evil, they are most often distrusted by other humanoid races because of the war for which they were bred, in which they allegedly fought alongside an army of mercenaries and chromatic dragons against the established human, dwarf, and elf kingdoms. Despite the tales that surround draconian history, no one has yet found any archaeological evidence to support the claim that such a war ever even took place. This has led some to believe that either the stories are incorrect or that the war was fought on some far off continent (or perhaps another plane entirely). Regardless of evidence, the draconian people are often judged according to their racial history rather than their own merits, a fact that leads to many disputes between the draconians and the other races.
Though draconians and draconids look much the same and have been known to interbreed, they are in fact two distinct races. While draconians were created in foul magic rituals that corrupted the eggs of metallic dragons, the draconids are the descendants of a single red dragon who sought to build an army by mating with countless humans and producing an alarming number of half-dragons. His full blooded dragon children did the same, and what resulted was a breed of humans with pronounced draconic features. The first draconids were trained to be mages, hence their name, and have passed the craft on to their descendants. Their progenitor has long since died, but his dragon offspring still lead isolated clans of draconids as representatives of their father, who supposedly ascended to godhood to be Tiamat's eternal mate. These dragon cults are fanatical and often contain members of non-dragonborn races, but these are encouraged to mate with dragons in order to strengthen the numbers of the cult. Most draconids live in and among human settlements instead of as members of the dragon cults, finding niches in human societies as long-lived mages, sages, and scholars. Draconids look like other dragonborn, but have skin that ranges from deep crimson to bright orange instead of the usual greens and browns of the draconians.
Both races use the standard dragonborn stats, although you might find feats, paragon paths, and magic items unique to each subrace here in the future.