In the 1970s, Heard appeared on the stage and in television and film. He appeared off-Broadway in 1974 in Mark Medoff's play "The Wager" and in 1975 as Guildenstern in "Hamlet" at the Delacorte Theatre in Central Park, where he also understudied Sam Waterston as Hamlet. That fall, the production moved to the Vivian Beaumont Theater at Lincoln Center. Heard appeared at the Eugene O'Neill Theater Center in 1977 in a series of new plays. Heard won Obie Awards for his performances in "Othello" and "Split" in 1979–80. He was the male lead in the 1979 film "Head Over Heels" (which was renamed and re-released as "Chilly Scenes of Winter" in 1982).