Richard graduated from Roosevelt High School and the University of Washington Professional Actor Training Program,[2] where he was a member of Beta Theta Pi.

After earning his drama degree in 1979, Karn moved to New York City, where in less than a week he was hired to do a commercial for Michelob beer that was featured during Super Bowl XIV.

When Karn joined the Screen Actors Guild, he was informed there was already a Richard Wilson, prompting him to drop his surname.

Karn found a place for them to live by managing an apartment complex, catering events at a Jewish synagogue on the side.

Karn was a guest star in the pilot episode but became a regular cast member when the show was picked up by the network.