Jim Carrey multitasks in "Lemony Snicket's A Series of Unfortunate Events," playing three characters without the aid of digital doubles. It's an old actor's tradition to attempt to create completely different personae within one piece, a practice that began in the theater. While playing multiple roles onstage was often borne out of necessity due to a small troupe, in the movies it's become a way of stretching one's acting muscles.

The acting pool was apparently small in the primordial film era as well, based on the myriad parts played by single actors in some early movies: In D.W. Griffith's "The Birth of a Nation" (1915), Joseph Henabery played 14 characters; Lupino Lane acted 24 parts in 1929's "Only Me"; and in the 1913 Queen Victoria biopic "Sixty Years a Queen," Rolf Leslie played a whopping 27 parts.

Digital technology makes it easy for actors to play against themselves today, but it wasn't always the case. In the Victorian-era tale of murder and rejection "Kind Hearts and Coronets" (1949), Alec Guinness plays six characters all in one scene (and two more people besides). A complicated system involving a frame with six painted glass windows was used to film Guinness as each character. The film was then wound back to shoot each successive character with different windows open.

Jerry Lewis' "The Family Jewels" from 1965 is the tale of an orphaned little girl who inherits $30 million and has to choose which of her uncles (all played by Lewis) will raise her. Of course, unlike Guinness' serious approach to creating differing personae, Lewis straps on funny fake mustaches, goofy outfits and ridiculously broad accents for his disparate characterizations. It sounds stupid (and it is stupid), but it's also pretty darn hilarious. No, really.

The prior year, Tony Randall earned his paycheck many times over in "The 7 Faces of Dr. Lao," a western fantasy about a circus sideshow that alters an Arizona town. Randall not only plays the titular owner of the circus, he also takes on Merlin, Medusa, a giant serpent, the Loch Ness Monster, the Abominable Snowman, Pan, Apollonius of Tyana, and even himself in a tiny cameo (can you have a cameo in a movie where you play nine parts?). The man who would be Felix Unger as a Chinese circus master in a western full of stop-motion monsters ... now that's what movies are all about!

But the master of the multiple roles was the late, great Peter Sellers. A true auteur of improvisation and character, Sellers perfected the art of schizophrenic acting while working on "The Goon Show," a legendary British radio comedy. But doing different voices is only one part of the picture. Sellers' early film efforts "Let's Go Crazy" (1951) and "The Mouse That Roared" (1959) and many British TV shows provided multiple-part training ground for his later triumphs with director Stanley Kubrick.

In "Lolita" (1962), Sellers technically only plays one person, Hollywood writer Clare Quilty. But within the film, Quilty masquerades as numerous people to get closer to the alluring nymphette played by Sue Lyons. As school psychologist Dr. Zempf, a too-inquisitive policeman and a mysterious midnight caller, Quilty tortures the already sweating adopted father/lover Humbert Humbert (James Mason).

But Sellers' masterpiece was "Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb." Re-teaming with director Kubrick in the 1964 Cold War black comedy, Sellers plays three distinct personalities: the nervous, proper British Group Captain Lionel Mandrake, the slightly dim U.S. President Merkin Muffley, and the deeply disturbed ex-Nazi scientist Dr. Strangelove, whose right arm has a mind of its own. It's one of the greatest comedic performances in the history of film ... or is that three of the greatest performances?

Of course, ensemble sketch troupes specialize in creating distinct characters, so it's no surprise that some of the most memorable multi-part performances come from the Monty Python fellas.

Monty Python's two narrative films, "Monty Python and the Holy Grail" (1975) and "Monty Python's Life of Brian" (1979) put the lads on overtime. Just listing the roles that a particular Python played is funnier than most whole films. F'rinstance, in "Holy Grail," Eric Idle portrays Dead Collector, Peasant 1, Sir Robin the Not-Quite-So-Brave-as-Sir Lancelot, First Swamp Castle Guard, Concorde, Roger the Shrubber and Brother Maynard. In "Life of Brian," Michael Palin is credited with Wise Man #3, Mr. Big Nose, Francis, Mrs. A, Ex-Leper, Announcer, Ben, Pontius Pilate, Boring Prophet, Eddie, Shoe Follower and Nisus Wettus. Ha ha! Ben!

In more recent years, two "Saturday Night Live" alumni have successfully tackled multiple roles. Paying homage to one of his comedic heroes, Eddie Murphy remade Jerry Lewis' "The Nutty Professor" in 1996, playing the overweight Sherman Klump, his svelte alter ego Buddy Love and five more characters, mostly the entire plump Klump family. Murphy would reprise all those parts and add one more to the mix in the 2000 sequel to the film.

And then, of course, there's Mike Myers, who has to do battle with himself in each of the "Austin Powers" films. After the great success of 1997's "Austin Powers: International Man of Mystery," in which Myers played both the hero and his arch enemy, the aptly christened Dr. Evil, sequels added more Myers villains to the gallery. In "Austin Powers: The Spy Who Shagged Me," we meet the ultimate gross-out bad guy, Fat Bastard, the repository for every bodily function joke Myers can think of (and he thinks of a lot of them). But more hilariously, 2002's "Austin Powers in Goldmember" introduced Myers as the dead-skin-eating, disco-loving Dutch baddie who kidnaps Austin's FAAA-JAH! If Myers continues adding one character per film, can we expect 10 roles from him in "Austin Powers 9: The Gay Nineties, Baby, Yeah!"?

Looking at the history of this practice, comedies have been the dominant genre. Perhaps less suspension of disbelief is required than in a drama. When Jeremy Irons played identical twins in David Cronenberg's 1988 psychological thriller, "Dead Ringers," the pairing of actor with himself was sometimes distracting rather than compelling. Still, with CGI, that old question of "How did they do that?" has been silenced forever, so maybe the time has come for more movie stars to work that dramatic tool and start playing more roles within one feature. Just think, a movie starring nobody but Ben Affleck in every single part!

Ohhh, technology can be a bad thing. Curse you, Rolf Leslie!

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