Michael Dorn was cast due to his theater training and the lack of a "street-accent". The character was intended to appear in seven of the first thirteen episodes, but after Dorn's performance in the pilot "Encounter at Farpoint", this was expanded to a series regular.
Due to Dorn's theatrical training and lack of a street accent, he was cast. Initially intended for seven of the first thirteen episodes, his performance in the pilot "Encounter at Farpoint" led to him becoming a series regular.