Will Smith portrays a father trying to scrape by on limited means in the surprisingly effective The Pursuit of Happyness.

It was 1988 when DJ Jazzy Jeff and the Fresh Prince hit mainstream gold, when the duo’s sophomore album became a smash hit, propelled by the hit single “Parents Just Don’t Understand.” And ever since then, everything Will Smith has taken on has been big—his solo albums, Independence Day, Bad Boys, Men in Black, his marriage to Jada Pinkett, it’s been Big Willie Style all the way. So it’s a bit ironic that he’s finally getting to some of his best work by going the other way, taking on a small movie. Yes, even though it’s being billed as a big Hollywood picture, The Pursuit of Happyness is just a sweet little story that happens to be anchored by one of the planet’s biggest movie stars. And before you ask, yes, the title is misspelled.

Now, Smith has coasted along for years, drawing on his extraordinary amount of charm to get by without breaking much of a dramatic sweat. We’ve always known he has decent acting chops, however, as was evidenced in his debut, Six Degrees of Separation, and Ali, which earned him an Oscar nod. But Happyness is a departure, and even though it treads the same ground as many other live-your-dream inspirational films, it’s generally effective. And it’s all on the shoulders of the artist-formerly-known-as-The-Fresh-Prince, who gives a sensitive, nuanced performance.

Based on a true story, Happyness finds Smith playing Chris Gardner, a medical equipment salesman in San Francisco in 1981, barely scraping by, almost unable to keep a roof over his own head, much less the heads of his wife (Thandie Newton) and son (Jaden Smith). But he wants more, and finds his way into an internship program at Dean Witter, determined to claw his way into the industry. His wife walks out, and Chris is forced to raise his son while going through an incredibly competitive program that has a slim chance of paying off with a real job. They are forced out of their home and soon wind up spending the nights in shelters or in worse conditions when there are no beds available. He is a trapped man, desperately trying to sell what little medical gear he has left, desperately trying to drum up sales for Dean Witter, desperate to keep his 5-year-old son healthy and safe. For a feel-good film, there’s a lot to see that doesn’t feel very good at all.

In spite of a script that follows the standard storybook line, Smith pulls all this part off, ably aided by his own son, Jaden, who plays Chris, Jr. The kid is extraordinarily cute and also a natural, which makes the proceedings all the more heartbreaking.

Look, there’s no shortage of down-on-your-luck films, but what makes Happyness work is how real the Gardner’s situation feels, even if the film itself falls into the occasional cliché. Chris Gardner isn’t plagued by the slings and arrows of outrageous fortune—these are the issues that face so many people that live a paycheck or two away from eviction. The pressure on him is staggering, and Smith delivers the emotional goods. Even the requisite “don’t let anyone tell you not to go after your dreams” speech is delivered nicely. There will definitely be some that find the piece as a whole trite, but this will move many to tears this holiday season.

THE PURSUIT OF HAPPYNESS ( * * * )

Directed by Gabriele Muccino. • Starring Will Smith, Jaden Smith and Thandie Newton. • PG-13, 117 min. • At the Century Cinemas Del Monte Center, Maya Cinemas, Northridge Cinemas.