Will Ferrell is a very funny guy. His lanky cluelessness has a slightly muddled but imperishable sweetness that gives an endearing quality to all the characters he plays, from SNL’s exemplar of ultimate school spirit, Craig the cheerleader, to the streaking newlywed who stole Old School from ostensible leads Luke Wilson and Vince Vaughn.

Ferrell’s first lead role is made to order, a sort of human Rudolph the Red-Nosed Reindeer, a North Pole misfit who shows his value and saves the day. Ferrell plays Buddy, a human raised as one of Santa’s elves, who discovers at age 30 that he has a real father named Walter (James Caan) who lives in New York and is on Santa’s “naughty” list.

Buddy leaves the North Pole to find Walter, knowing only what he has learned from the elves. Thus, he is a whiz at making snowflake decorations and spreading good cheer, and he always assumes the best about everyone. But these are not especially useful skills in New York City.

Walter is in trouble with his boss, a publisher of children’s books, because he has to find a successful new story by Christmas Eve. At first, he does not believe that Buddy is his son, but after he passes a DNA test, Walter reluctantly brings him home to meet his wife (Mary Steenburgen) and son. When Buddy stops by the Santa display at Gimbel’s, he meets pretty Jovie (Zooey Deschanel), who is too shy to sing in front of other people. On his way to saving the day and a happy ending for everyone from the North Pole to Manhattan island, Buddy gets many chances to do silly things as he experiences New York city and gets to know Jovie and his family.

Some jokes work better than others. The movie can’t seem to make up its mind whether people should need proof of Santa’s existence or not. And the talents of Caan, Steenburgen, Bob Newhart (as Buddy’s adoptive father) and Ed Asner (as Santa) are neglected. But director Jon Favreau (who appears briefly as a doctor) shows some verve and keeps the story moving quickly enough to keep it from feeling like a series of skits. Deschanel (Big Trouble and Almost Famous) nicely shows us the way Buddy appeals to Jovie’s longing for a place where singing and sweetness are encouraged. And it’s nice to hear the Oscar-winning “Baby, It’s Cold Outside” duet sung so sweetly. Peter Dinklage (The Station Agent)has a marvelous cameo as a haughty French-cuffed author of children’s books, making his appearance much more than a sight gag. And Ferrell is just plain fun to watch. His naive pleasure in the world around him is ultimately almost as endearing to us as it is to (almost) everyone he meets.

Parents should know that the movie has some mild potty humor and a couple of gross-out gags involving burping, barfing, and eating some pretty disgusting things. The plot touches on an out-of-wedlock child and DNA testing as proof of paternity. Some younger children might be upset that Buddy’s mother died and that his father never knew about him. There is mild comic peril. A character gets drunk.

Families who see this movie should talk about how the other characters felt about Buddy’s cheer and enthusiasm. If you arrived in your town after 30 years at the North Pole, what would surprise and delight you the way that the escalator and revolving door surprised and delighted Buddy?

Families who enjoy this movie will also enjoy The Santa Clause, Home Alone, and the original Miracle on 34th Street. That classic (ignore the palid remakes) is about the rivalry between Macy’s and its then-rival Gimbals, which despite its appearance in this movie, closed for business years ago. Families might even like to try some of Buddy’s holiday decorating ideas, though probably not his recipes!