Dwarves

Strong, stocky, and the largest of the small races, the dwarves are skilled builders and boast a long tradition of courage and martial skill that has served them well in their constant struggle against the dangers of the Underdark. Their civilization was originally spread out amongst 12 massive thaigs, or underground cities. Currently, only 10 of the 12 thaigs remain. One was lost to a colony of invasive mind flayers and the other was abandoned due to a delirium crisis.
Dwarves are the second most advanced society on Rhune, largely due to the headstart they were granted by the Collision Event. Thanks to the underground nature of their way of life, the Collision set them back the least. In fact, the Collision helped advance them further. They harnessed the energy and material left in the crater to forge terrifyingly strong weapons, armor, and beasts. But, as a side-effect of working with this material, Dwarves have seen a sharp decline in birth rates, causing widespread fear regarding the future of the race. On top of this, they're unable to produce their own magic and must rely on gifted power- be it from a powerful god or patron.
Dwarven culture is caste-based, and every dwarf is born into their caste. These castes (from least to most societally important) are servants, artisans, miners, smiths, merchants, warriors and nobles. Dwarves know their station and will very rarely move from one caste to another after birth. Regardless of their social status, a dwarf gets fulfillment from mastering their position.
There are two kinds of dwarves: those born of stone and those kissed by the sun. A dwarf that's born of stone is considered the "standard" dwarf and is typically just referred to as a dwarf. They ascribe to the above cultural norms. A sun-kissed drawf is a dwarf that was either born above ground or ventured above ground for some important purpose. They are seen as casteless and therefore have less social status than the servant caste. Additionally, they aren't allowed to return unless they fulfill their purpose or can provide something of high import to the thaig.
It is a dwarf's greatest fear to die under the open sky as no afterlife awaits those who meet this fate.