Vin Diesel on Diaper Patrol

Vin Diesel punched his way to the top, and then critics pummeled him into a corner. Now, the tough guy is taking a swing at wrestling rugrats in a family comedy.

Every big action star reaches that point when it's time to think beyond gun-and-gut glory. Unfortunately, rippling biceps don't help much when you're throwing punch lines.

Arnold Schwarzenegger scored big as Danny DeVito's doppelganger in "Twins." But before he leaves office, the California governor may still yet issue himself a formal pardon for his turn as the world's first pregnant man in "Junior."

Then there are the out-and-out disasters. Remember Sylvester Stallone in "Stop! Or My Mom Will Shoot"?

Now Diesel braves the uncertain waters of lighthearted comedy. In "The Pacifier," opening today, the "xXx" beefcake plays a Navy SEAL who flubs a mission guarding a government scientist and tries to redeem himself by guarding the slain man's five cute-as-a-bug kids from evildoers.

"What was so cool about this picture is that it played off the perception of previous characters I've played," says Diesel. "That's what's so much fun for me."

At 37, Diesel has blazed a fast and furious path to a major turning point in his career. His last film, "The Chronicles of Riddick," a follow-up to "Pitch Black," was a major disappointment. At the same time, he passed up opportunities to appear in sequels to "The Fast and the Furious" and "xXx."

Suddenly, a red-hot action hero who quickly established three film franchises might not have any, unless someone pitches "The Eulogy of Riddick."

Still, it'd be wrong to call this foray into comedy career desperation. Diesel has serious ambitions to flex much more than his biceps. He's currently planning to direct, produce and star in "Hannibal," the story of the Carthaginian general who in 218 B.C. rode with an army of elephants across the Alps to attack Rome.

Paramount Pictures is planning to release the big-budget, sword-and-sandals epic in 2006 -- long enough, perhaps, for moviegoers to forget Colin Farrell in "Alexander" and still remember Russell Crowe in "Gladiator."

Diesel also fancies himself in musicals. With Miramax considering a remake of "Guys and Dolls," producers say he's privately campaigning to be a singing gangster. The original movie starred Frank Sinatra alongside another big-screen tough guy who had never before sung in public -- Marlon Brando.

With such ambitions, Diesel's testing his versatility in "The Pacifier." Schwarzenegger found success in "Kindergarten Cop," a 1990 movie that grossed more than $200 million, wherein the Terminator proved to be a cuddly foil for an army of brats.

Replicating such success, however, is always tempting, and never easy. Hulk Hogan tried and failed in 1993's "Mr. Nanny."

One thing Diesel has going for him: He didn't come to acting from the World Wrestling Entertainment. As a teen, he began acting in his father's repertory company and moved on to the Off-Off Broadway circuit, earning tough-guy credibility on the side as a bouncer.

"Multi-Facial," an autobiographical short film about Diesel's early struggles as an actor, caught Steven Spielberg's eye after it was accepted at the 1995 Cannes Film Festival, leading to his big break in "Saving Private Ryan."

In "The Pacifier," Diesel tries his hand at playing the straight man.

"One of the great things about him doing this is that I told him, 'If you dare to try to be funny, I will literally have you murdered. I will have you murdered, because you are the straight guy in this movie. You are the reactor to all of the mayhem going around,' " said director Adam Shankman, who previously helmed "Bringing Down the House" and "The Wedding Planner."

Brad Garrett of "Everybody Loves Raymond" plays the school vice principal who becomes Diesel's nemesis. And the role affords Diesel a lighthearted romance with Lauren Graham of "The Gilmore Girls."

But like "Kindergarten Cop," the success of the movie will ride largely on Diesel's chemistry with the kids, and Diesel dutifully plays it straight.

"I'm never going be able to remember your names because there's not enough time," his character tells the kids. "So you're Red One, you're Red Two, you're Red Three and you're Red Baby."

Of course, once Diesel changes his first diaper, he'll never forget their names. As the tough guy puts it, "Ewwww, Red Baby!"