Moving to Hollywood in 1973, he worked in episodics, as well as TV-movies like "Death Race" and "The Girl Most Likely To . . ." (both ABC, 1973), before making an auspicious feature debut with an excellent comic performance in Jonathan Kaplan's light-hearted, drive-in sex comedy "Night Call Nurses" (1974), followed by appearances in "The Day of the Locust", "Night Moves" and "Smile" the following year. Dugan raised his profile significantly in 1976, first portraying Nick Nolte's best friend in the most-watched miniseries of its time, "Rich Man, Poor Man" (ABC), and later creating the title character of "Richie Brockelman: The Missing 24 Hours", an NBC TV-movie that also marked important career connections with executive producers Stephen J Cannell and Steven Bochco. He later reprised that role on episodes of NBC's "The Rockford Files" and in the short-lived 1978 spin-off series "Richie Brockelman, Private Eye".
After one more go at Brockelman in yet another episode of "The Rockford Files", Dugan landed the recurring role of Captain Freedom in the Bochco-produced "Hill Street Blues" (NBC) in 1982. He returned as a series regular heading the cast of "Empire" (CBS, 1984), a sitcom spoof of the then-popular "Dallas". He also added a zany touch as the wisecracking tabloid reporter Edgar 'Benny' Benedek in the comedy-fantasy "Shadow Chasers" (ABC, 1985-86). By this time, Dugan was very interested in stepping behind the camera and he embarked on a five-month apprenticeship at Stephen J Cannell Productions, culminating in his first directing assignments, two 1987 episodes of the NBC series "Hunter". He also helmed episodes the following year of the Cannell-produced series "Wise Guy" and "Sonny Spoon" while beginning his run in the recurring role as Cybill Shepherd's husband in the ABC series "Moonlighting". When its producers discovered he was directing for other series, they brought him on board to helm numerous episodes of the show's last season (1988-89).
In addition to his new career as a TV director, Dugan also continued acting in features although very few parts were memorable. It was perhaps inevitable that he would move to the helmer's chair for features and in 1990, he made his directorial debut with "Problem Child" (1990), a botched comic twist on "The Bad Seed" that had some amusing moments. Dugan attempted valiantly to recreate the flavor of the Marx Brothers' 1935 classic "A Night at the Opera" with John Turturro (Groucho), Bob Nelson (Harpo), Mel Smith (Chico) and Nancy Marchand (Margaret Dumont) scoring high marks for good intentions without really pulling it off. He delivered a commercial, if not critical, success with "Happy Gilmore" (1996), starring "Saturday Night Live" cast member Adam Sandler in one of his patented, puerile roles as a lovable loser. Taking its inspiration from "Caddyshack", this golfing comedy fell far below the level of its model while managing to gross a combined $75 million between box-office and video rentals, insuring that the greatest laughs occurred on the way to the bank. The director next teamed with another "SNL" star--Chris Farley--on "Beverly Hills Ninja" (1997), which opened at the Number One less than a year later (before word of mouth effectively killed it), giving him the distinction of being the only director to have two films open in less than 11 months in the top two spots on the box-office charts. Dugan reteamed with Sandler on "Big Daddy" (1999), bringing his expertise for working with children (particularly on "Problem Child") to the project co-starring twins Cole and Dylan Sprouse (from the ABC series "Grace Under Fire") as the little boy who enters and changes a feckless slacker's (Sandler) life. Without Sandler, however, Dugan's next comedic effort, 2001's limp sex farce "Saving Silverman" was a flop. The director next teamed with a top-level star, comedian Martin Lawrence, for his next effort, "National Security" (2003).
Dugan has not given up acting (he manages to take on roles in many of the films he helms), but directing has enabled him to be a little more exclusive about the parts he takes. Despite graduating to the big screen, he has continued to work frequently as a TV director through the 90s, often on series produced by Bochco, including episodes of "Civil Wars" and "Doogie Howser, M.D." (both on ABC during the 1992-93 season), "L.A. Law" (NBC, 1993-94 season), "Byrds of Paradise" (ABC, 1994) and "NYPD Blue" (ABC, 1993-95; 1997-98 seasons). For Cannell Productions, he helmed episodes of "Traps" (CBS, 1994), not to mention the pilot for the executive producer's "Marker" (UPN, 1995), and "Doogie Howser" inaugurated a creative relationship with yet another TV series heavyweight David E Kelley, an association he would renew helming episodes of the hit series "Picket Fences" (CBS, 1993-95 seasons), "Chicago Hope" (1994-95 season) and "Ally McBeal" (Fox, 1997-98 season). Dugan also worked as a director for two other UPN vehicles, "Love Boat: the Next Wave" (1998-99) and the musical comedy series "Shasta McNasty" (1999- ).