Dwarves love being underground mining. In fact, many are addicted to it. The promise of buried treasure is more than most dwarves can resist. Because of this, dwarves get a mining skill bonus. As the name implies, dwarves are short. They are not so bright or perceptive, but stocky and tough. They also have infravision (see infrared light), which helps them to see in dark areas. Oh, and did I mention they are stubborn (i.e. high confidence and willpower)?