Actors Who Played Their Own Twin in Movies and Television

Ruffalo plays twins in HBO's new miniseries, I Know This Much Is True, which is based off of Wally Lamb's 1998 novel of the same name.

In the show, Ruffalo plays identical twin brothers, Dominick and Thomas Birdsey, the latter of whom is schizophrenic.

At the TV Critics Association Winter Press Tour in January, Ruffalo revealed he gained 30 lbs. for his dual role. He also revealed that he filmed all of his scenes as Dominick for the first 15 weeks, and then took five weeks off to transform into Thomas.

Due to Thomas' years of dependency on medication for his schizophrenia, Ruffalo said he gained weight to accurately portray the effect medications and "mood stabilizers" can have on someone's body.

"We didn't want it to be like I run and throw a wig on and do the same scene in the same day, so we took six weeks off to really separate these two guys," Ruffalo explained.

The star played twin brothers, Ronnie and Reggie Kray, in Legend, a film adapted from John Pearson's book on the real-life Kray twins, who were mobsters in a gang known as "The Firm" in England during the '50s and '60s.

Hardy said of the dual roles, "The two characters, they were pretty easy to slip between. The complicated part was to make an audience believe it wasn't one performer doing both parts."

In an interview with Entertainment Weekly, Brian Hegland, who directed the film, said that filming went like this: "Tom and I would rehearse in the morning. I would read Ron and he would do Reggie. At which point, once we had the scene down, he would record Ron's end of the dialog. He'd always play Reggie first, and we'd play Ron in an ear-piece, so he could at least act off his own performance, or a kind of 70 percent performance of Ron, since we hadn't filmed him yet. Then he'd go and change into Ron mode. Ron wore glasses, he was heavier, he was taller, he had a different hairline. That took a lot of the pressure off. You're not ping-ponging between two identical twins."

In the Nancy Meyers remake of The Parent Trap, a young Lohan filled Hayley Mills' shoes when she played both Hallie Parker and Annie James.

Lohan was so good at playing both roles that she had many convinced that real-life twin actors had starred in the film. That included her onscreen dad, Dennis Quaid, who told IMDb, "Lindsay Lohan was 11 when she started filming ... She was a savant. She just could channel anything like that. Some people are like that and the rest of us have to work at it."

Lohan channeled twins again for the 2007 thriller, I Know Who Killed Me. The movie wasn't exactly a success, but it does serve as proof that Lohan loves a good twin role.

The Call Me By Your Name star played twins in The Social Network, but it wasn't your typical green-screen-body-double work that made it happen.

In fact, director David Fincher told Entertainment Weekly that the twins are actually played by two different actors. "Hammer played the main twin in each shot. For shots that included both twins at the same time, [model Josh] Pence stood in for the second twin; Hammer later went into a studio, where he strapped his head into a harness to film that twin's face and voice, which was then digitally superimposed over Pence's face in the film. The result is a sort of hybrid actor with Hammer's head and Pence's body."

Cage played twin brothers, Charlie and Donald Kaufman, in the 2002 Spike Jonze film. The film boasts an impressive cast list with Meryl Streep, Chris Cooper, Tilda Swinton and Maggie Gyllenhaal playing supporting roles.

Cage was nominated for both an Oscar and Golden Globe for his work.

Norton played polar opposite twins in the 2009 dark comedy. Bill is a straight-laced professor, while his estranged twin brother Brady is a drug dealer. Bill travels to Oklahoma after Brady's alleged death, only to find that he isn't dead at all and that they are now both roped into his drug dealing scheme.

The cast includes Richard Dreyfuss, Susan Sarandon and Keri Russell.

In most cases, two is better than one, but not when it comes to Van Damme. The action star took on the role of twins in the 1991 action flick about twins who were separated at birth, but brought together to fight crime.

The 1992 action comedy starred Jackie Chan as twin brothers who were separated at birth. One is a concert pianist and conductor, the other is a martial artist. Together, they manage to take down a powerful gang that is the reason for their separation in the first place.

What's better than one set of twins?! Two sets of twins! Because of a mix-up at the hospital, Tomlin and Midler are separated from their identical twin sisters and instead live their lives as fraternal twins in two very different families. To make things worse, the sets of twins are also named the same. It's ... confusing and delightful.

The film is loosely based off of Shakespeare's Comedy of Errors.

In the 1998 film based on Alexandre Dumas's d'Artagnan Romances, a.k.a. the stories of the Three Musketeers, DiCaprio played both the hero and the villain: King Louis XIV and Philippe, the King's brother and man in the aforementioned iron mask.

The 1964 film starred Bette Davis as estranged twin sisters Margaret DeLorca and Edith Phillips, who meet again after Margaret's husband dies.

The sisters, it turns out, had a falling out because of Margaret's husband, Frank, originally was meant to marry Edith, but cheated on her with Margaret. Margaret sealed their marriage by faking a pregnancy, forcing Frank to marry her.

Edith eventually murders her own sister, stages it as a suicide, and pretends to be Margaret in order to live more comfortably. It is all very confusing and messy. Families, right?

Adam Sandler played both the male and female version of himself in this 2011 comedy about a twin sister, Jill, who overstays her welcome with her brother Jack's family. The film also stars Al Pacino and Katie Holmes.

Though it boasts a dismal 3% on Rotten Tomatoes, the film performed well at the box office.

This twin reveal is a huge spoiler if you haven't seen the 2006 film Prestige, which follows Bale and Hugh Jackman playing rival magicians.

Turns out that Bale's character, Alfred Borden, isn't really that good at magic: He just has a twin brother helping him pull off the stunts.

Jackman's character, Robert Angier, doesn't know that, and literally stops at nothing to recreate a trick known as the Transported Man.

Irons played Elliot and Beverly Mantle, identical twin gynecologists, in this 1988 thriller. The twins are polar opposites, but eventually their relationship dynamic is thrown off by women. Irons gives two incredibly compelling performances.

Lisa Kudrow played her own twin sister, Ursula, (who was pretty evil in, like, a funny way) on Friends.

The role wasn't entirely accidental. Kudrow played Ursula, a waitress, in Mad About You, which ran back-to-back with Friends. Kudrow explained, "When Friends got its time slot on Thursday night at 8:30, after Mad About You, everybody realized, 'We need some explanation for the audience - Why are they seeing the same girl with the same voice at 8:00 and 8:30 on two different shows?'"