Harold Lam is House's primary rival in the annual Greater Schenectady Chili Cook-Off and Spud Gun Tournament's spud gun competition. He appears for the first time in The Dig although it is clear that he and House have known each other for years. He is portrayed by actor Justin Chon. Harold is well known to House as a serial harasser of any good looking woman, especially women connected to House. He warns Thirteen about Harold in this regard.