In the course of the three National Lampoon vacation movies, Clark Griswold has become an emblem for all that is sweetest and most ineffectual in the Hollywood husband. What he wishes for his family, most desperately, is that they have a good time. All he is able to deliver is chaos and hair-raising misadventures. His wife is at least loving and grateful, but his two children are thoroughly weary of his schemes and have lost all faith in his ability to deliver on his promises.
"National Lampoon's Christmas Vacation," the third in the series, rings a small change on the formula. Instead of the Griswolds going on vacation, their relatives take vacations to visit them. By Christmas Eve, the Griswold household is vibrating with the pent-up anxieties and resentments of two sets of in-laws, a thoroughly wacko uncle and aunt, and a hillbilly cousin who seems to have traveled in his camper directly from Dogpatch.
None of these people are particularly good examples of the Christmas spirit. And the Griswsold children have grown sullen and ill-tempered, especially when Clark tries to enlist them in such projects as decorating the home with 125,000 light bulbs. Everything that can possibly go wrong will, of course, go wrong, and that includes Griswold locking himself in the attic, falling off the roof and being assaulted by the hillbilly cousin's ravenous hound.
There are long stretches in "National Lampoon's Christmas Vacation" when this almost works. The movie is curious in how close it comes to delivering on its material: Sequence after sequence seems to contain all the necessary material, to be well on the way toward a payoff, and then it somehow doesn't work.