The Dwarven social hierarchy is ruled by complex, interrelated, and rigid castes. The casteless are the lowest rung of Dwarven society: outcasts in their own city, unable to take up work among the higher castes, Dwarves rejected by the Stone itself. Dwarves who are exiled or born on the surface are also officially casteless – but with an increase in the number of higher-caste Dwarves choosing to live on the surface, it is becoming difficult for some surface dwarves to be considered permanent exiles. The average Dwarf will never see the surface, and often will have superstitious beliefs concerning surface-life (such as falling into the sky, or the sun falling to the ground). Those dwarves who are most commonly seen on the surface tend to be merchants and traders, or on occasion smiths, but amongst the dwarves they might have been thieves, murderers or worse.
Above the casteless (in no particular order) are merchants, miners, smiths, warriors, servants (only one step above casteless), nobles, and Stone Callers. Nobles are the nobility of Dwarven society, while the Stone Callers are a group of dwarves who participate in the Conclave on behalf of their noble houses. While it is possible for some dwarves to better their family’s station by performing great deeds and/or siring children with higher-caste dwarves, these remain rare and difficult circumstances. Lower-caste dwarves who rise in caste are generally considered “upjumped” by the highest castes. In dwarven society, children inherit the caste of their same-sex parent; should a son be born, he would inherit his father’s caste, or castelessness, should that be the case.
(Taken from Dragon Age Wiki and re-worded for campaign setting)