National Lampoon's Christmas Vacation

Factual error: In the scene where Clark is working on the lights the full moon is shown. This is December 14th according to the advent calendar. On December 24th when Santa's sleigh goes sailing over the moon, it is still full.

David Schaal

Factual error: Prior to the cat being electrocuted, Clark is seen plugging the lights into a 110 volt outlet. However, when Rusty resets the breaker, it is a double pull breaker that is reset, which typically provides 220 volts, and the breaker is off instead of tripped. (01:09:00)

Factual error: When Clark is sliding on the saucer, he shoots out a shower of sparks when he crosses the street. Those old saucers were made of aluminum, and aluminum can't create sparks like other metal does.

Factual error: The family is reacting to where Clark went flying down on his saucer, ending up in a Wal-Mart. With the speed and length of the trip, he would've been out of sight in seconds. There was no way that they could see him from where they were.

Factual error: Even though this movie takes place at Christmas and there is lots of snow around the outside of the house, you can tell this was filmed during the summertime due to the short shadows in some outside scenes. At Christmas time, shadows are longer all day long.

Continuity mistake: In an early shot of the outside of the house, the motorhome that Eddie and family show up in is parked in the driveway. The problem is, they don't appear until later in the film. (00:37:55)

More mistakes in National Lampoon's Christmas Vacation

Todd: Hey, Griswold. Where do you think you're gonna put a tree that big?
Clark: Bend over and I'll show you.
Todd: You've got a lot of nerve talking to me like that, Griswold.
Clark: I wasn't talking to you.

More quotes from National Lampoon's Christmas Vacation

Trivia: When Clark smashes up the decorations when he can't get the lights working, Chevy Chase genuinely broke a finger when he punched Santa, but stayed in character, kicking the decorations instead, and that's the take used in the film.

More trivia for National Lampoon's Christmas Vacation

Question: At the Christmas dinner, what is the tree ornament behind Clark as he's cutting the turkey?

More questions & answers from National Lampoon's Christmas Vacation