Dragonmarks are physical manifestations of the Draconic Prophecy. They have appeared on seven of Khorvaire's common races. They are more intricate than a birthmark and more distinct than a tattoo. There are twelve families of dragonmarks; originally there were thirteen, but no living creature on Eberron possesses the destroyed mark of House Vol. In addition to being a status symbol in Khorvaire, the dragonmarks provide the bearer with magical talents.
Dragonmarks typically appear in the bearer's adolescence as they pass through puberty, however, this is not exclusively the case. There are three distinct manifestations of each dragonmark that correlate in size, intricacy, and power. As the dragonmark gains power (from least to greater) it will expand in size and complexity rather than forming a different mark. Often the mark will manifest first as the least mark and through study and focus the bearer increases their power and with this increase, the dragonmark also increases granting additional abilities. However, there are some who will manifest a lesser mark or even greater mark without explanation. House members who manifest even the least dragonmark, however, can expect at least some change in their lifestyle as they find new and better employment opportunities within their house guilds as well as new social avenues to explore.
The dragonmarks are passed through bloodlines and when two members of different dragonmarked families reproduce it often results in aberrant dragonmarks. The aberrant marks do not manifest identically each time therefore it is possible for two individuals with completely different looking marks to produce the same magical effect using the mark. Indeed, each aberrant dragonmark is completely unique to its bearer. Originally aberrant marked were seen as outcasts and outsiders. Often they were shunned by the houses and eked out a pitiful existence. Many members bearing these aberrant dragonmarks have since united in their differences and formed House Tarkanan, most notably present in Sharn.