‘Christmas Vacation’ Director Once Explained Exactly Why He Cast Johnny Galecki as Rusty Griswold

National Lampoon’s Christmas Vacation is one of many popular holiday movies. The 1989 comedy starring Chevy Chase as Clark Griswold, a father who wants to give his family the perfect Christmas, is the third installment in the National Lampoon’s film series.

In keeping with previous Vacation movies, the roles of Clark’s children, Audrey and Rusty Griswold, were recast with every new release. This is how Johnny Galecki ended up auditioning for the role of Rusty and getting cast in Christmas Vacation

Johnny Galecki’s ‘sense of humor’ caught the director’s attention 

Johnny Galecki, Juliette Lewis, Diane Ladd, Chevy Chase, and Beverly D'Angelo attend a 30th anniversary screening of 'National Lampoon's Christmas Vacation'
Johnny Galecki, Juliette Lewis, Diane Ladd, Chevy Chase, and Beverly D’Angelo attend a 30th-anniversary screening of National Lampoon’s Christmas Vacation | Jean Baptiste Lacroix/Getty Images

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In a 2014 interview with Rolling Stone, members of the Christmas Vacation cast sat down with director Jeremiah S. Checknik to discuss the seasonal favorite. Reflecting on the casting process, Checknik recalled what stood out to him about Galecki. 

“Galecki was just an odd kid. He was very young and so dry,” Checknik said. “He made me laugh because he has this wack of a sense of humor and that’s what made me really want him.”

“He wasn’t a Hollywood kid who was going for laughs, but he had a nervousness to him that in many ways shows beautifully now as an adult,” he added. “His comic gifts are absolutely incredible.”

At the age of 14, Galecki spent the majority of Christmas Vacation acting alongside Chase, Beverly D’Angelo (Ellen Griswold), and Juliette Lewis (Audrey Griswold). 

RELATED: The 10 Best Christmas Movies Ever, According to Rotten Tomatoes

Johnny Galecki says a ‘Christmas Vacation’ audition would’ve ‘been enough’ for him

When Galecki sent in an audition tape for Christmas Vacation he didn’t think his chances of getting cast in the movie were high. He didn’t have much acting experience and he wasn’t auditioning for major movies. 

“At the time, I was in Chicago auditioning for industrial films and regional theater, and I was happy doing that. I didn’t dare to dream to be in a big studio film. But I put myself on tape and sent it in,” he told Rolling Stone in 2014. 

He got a call about soon was heading to Los Angeles for an audition. 

“They flew me out to Los Angeles; it was one of the first times I was ever here. I read with Chevy and Jeremiah — and that alone would have been enough for me,” Galecki said. “I could have been given my walking papers and sent home on the next flight and it still would have been a dream come true.”

He didn’t have to wait long to find out he’d landed the part of Rusty. Chase told him “right there in the room” they wanted him for the role. 

RELATED: Chevy Chase Thinks ‘It’s the Silliest Thing’ When People Compare ‘Christmas Vacation’ To ‘It’s a Wonderful Life’

Johnny Galecki is now 1 of the highest-paid TV actors 

Decades since Christmas Vacation, Galecki is now a successful actor in Hollywood. Starring on the hit CBS series, The Big Bang Theory, he became one of the highest-paid actors on television.

He, along with some of his co-stars, earned $900,000 per episode. The comedy isn’t the only program Galecki’s known for. He also made appearances on Roseanne and continues to work in TV and film. 

Catch Christmas Vacation on TV because it’s not available to stream on Netflix