WATCH: Julia Roberts plays 'Face Balls' with Jimmy Fallon

Cast member Julia Roberts attends the premiere of "Valentine's Day" at the Grauman's Chinese theatre in Hollywood, California February 8, 2010. The movie opens in the U.S. on February 12. REUTERS/Mario Anzuoni (UNITED STATES - Tags: ENTERTAINMENT)

Cast member Julia Roberts arrives for the "August: Osage County" screening at the 38th Toronto International Film Festival in Toronto, September 9, 2013. REUTERS/Mark Blinch (CANADA - Tags: ENTERTAINMENT) - RTX13EVR

Julia Roberts took several balls to the face on Thursday.

During the actress' appearance on The Tonight Show, Jimmy Fallon invited her to play a game of "Face Balls." The rules are simple: Roberts and Fallon take turns throwing balls at each other's faces. Footage of the impact is then shown in slow motion. Laughter ensues.

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"There are so many jokes, it's giving me a headache," Roberts bewailed, before continuing her dirty quips. "This is like the comedy version of Fifty Shades of Grey."

View original VIDEO: Julia Roberts Plays "Face Balls" with Jimmy Fallon at TVGuide.com