Frankie Muniz ("Malcolm in the Middle") stars as 14-year old Jason Shepherd, a habitual liar who uses his dubious talents to avoid getting out of schoolwork. His outrageous lies trip him up once and for all when he fails to complete a thousand word story for English class and is threatened with summer school by his teacher. She agrees to give him a pass, provided he can get the story on her desk by 6:00 PM the same day. Dreading the thought of spending all summer in a classroom, Jason buckles down and writes something he calls "Big Fat Liar." The tale has its roots in his own penchant for not telling the truth.

Paul Giamatti plays a movie producer scamming 14-year old Frankie Muniz in Big Fat Liar

Jason furiously pedals on his bicycle to deliver the story in time. He is halted when his bike slams into a limousine carrying Marty Wolf (Paul Giamatti), a big-time Hollywood movie producer. After a brief discussion, Wolf spots the story, decides it's pretty good, and takes off with it. Jason, meanwhile, ends up in summer school. Not long after, Jason is at the movies with his girlfriend Kaylee (Amanda Bynes of Nickelodeon's "The Amanda Show") when he sees a preview for the newest Marty Wolf production: a sure-to-be blockbuster called "Big Fat Liar." Furious that the show biz weasel stole his idea, Jason recruits Kaylee to join him on a road trip to Los Angeles where he plans to track down Wolf and get even. The kid doesn't so much want credit for the idea as much as he wants Wolf to let his teacher and parents know that he really did write that story.

I kind of liked Big Fat Liar up to this point. For a time, I thought it might be a pint-sized version Robert Altman's movie-skewering satire The Player. But just when the film should be getting revved up, it falls apart. Jason and Kaylee sneak onto the Universal Studios lot and end up staying in the prop room. This allows for totally gratuitous scenes in which they lean against a raptor from Jurassic Park, or lounge on the hood of Marty McFly's DeLorean, or converse in front of Jim Carrey's Grinch outfit. While I'm sure every kid in America (including this big kid) would love to have a major studio prop room as their own personal playground, the effect here serves only to remind us of so many better movies. Later on, the kids do some "clothes shopping" in the studio's wardrobe department. This scene is handled with one of those endless music montages in which we see the characters trying on all kinds of clothes while pop music blasts from the soundtrack. Didn't those montages go out of style in the 80's?

A bigger problem is that the film stops being about the characters and turns into a routine slapstick comedy that focuses on the antics Jason and Kaylee perform to make Wolf suffer. Among other things, they put blue dye into his swimming pool so that his skin gets tinted after a swim. They also turn his hair orange, send him to a place where he gets beaten up, and attempt to ruin his career. Paul Giamatti is a terrific actor who's good at playing indignation, but there's just nothing funny about watching someone get humiliated over and over. Big Fat Liar seems to think it's hilarious watching these teenagers pull dopey pranks. (It doesn't help that the things they do are in no way realistic.)

The movie's attitude is really kind of offensive. It sends a very clear message to young viewers: it's okay to get revenge against someone you don't like. By the story's end, Jason has effectively ruined Wolf. No, he is not a nice man and he mistreats those around him - but does that make it okay? Jason is actually turned into a hero for his acts of vengeance. He earns the respect of his girlfriend, his teacher, and his parents. I've never been one to blame TV or movies for society's ills, nor do I intend to start here. However, I can't imagine that any parent would want to take their child to see a movie with such a blatantly antisocial message. Worst of all, I don't even think the filmmakers knew their movie contained this message. On the surface, the overly earnest conclusion looks like it's saying that telling the truth is good. I'm sure that was the original intention, but what the movie wants to say and what it actually says are two very different things.

Philosophical objections aside, this just isn't a very good movie. I laughed a few times - mostly at Giamatti's performance - and then sat silently for long stretches. The whole film rests on the assumption that this kid's story becomes the basis for a much-beloved blockbuster. This premise leads me to ask one obvious question: if Jason's movie is so great, why did they choose to make this one?

( 1/2 out of four)

Big Fat Liar is rated PG for some language. The running time is 1 hour and 28 minutes.