In the first half-hour of the new Farrelly brothers comedy, "The Ringer," words like "retard" and "feeb" are freely tossed about as a man persuades his nephew Steve (played by the former "Jackass" Johnny Knoxville) to pretend to be mentally disabled so as to easily win the gold in the Special Olympics.

Audiences will laugh, perhaps nervously, guiltily: Studying up his " 'tard" behavior by watching "Forrest Gump," Knoxville becomes "Jeffy," sporting red gym shorts pulled way too high. The movie opened Friday and should further the Farrelly brothers' place in the universe of crass. And that discomfort you feel laughing at it?

All part of the plan.

And here is where you would normally place your bets on how quickly the people who run the Special Olympics would unleash a mighty indignation on behalf of those now called the intellectually disabled and immediately begin issuing press releases demanding an apology.

But you'd lose that bet.

The Special Olympics gives "The Ringer" five thumbs up! The group's official endorsement came out weeks ago. (The National Association for Down Syndrome has also given its assent.) Almost from the start, Special Olympics International made an unlikely deal with the rascally Farrellys to assist this most unusual and ambitious comedy — under certain conditions. It was two years of negotiations between the Special Olympics and the filmmakers before a single frame was shot. Now everyone involved is holding their collective breath, waiting to see if critics and/or audiences will appreciate the fine line between irreverent humor and permission to mock.

"The risk of failing was enormous, but the upside of succeeding was even bigger," says Special Olympics Chairman Timothy Shriver.

In his office at Special Olympics headquarters in Washington, D.C., he does look Kennedyesque. The eyes, the perfect hair, the easy classiness. He is the 46-year-old Yale-educated son of Sargent and Eunice Kennedy Shriver — the do-good wing of the Kennedy clan.

His father, Sargent, is the devoted public servant who shaped the Peace Corps, the Job Corps and Head Start, and directed Lyndon Johnson's War on Poverty programs. His mother, Eunice, was inspired by her intellectually disabled sister, Rosemary, to found the Special Olympics in 1968, marching youngsters onto Chicago's Soldier Field for the first international games.

"I've had good role models," says Shriver, who since joining the Special Olympics as president in 1996 has gradually taken charge for his parents (his father suffers from Alzheimer's and his mother is recovering from a stroke), becoming chairman in 2003. He splits his time between the Washington office and traveling to any of 30,000 competitions in more than 150 countries. He's also kept a hand in moviemaking of the upstanding kind, co-producing the 1997 slave saga "Amistad" and Disney's 2000 triumph-over-disability, "The Loretta Claiborne Story."

And now to his resume, add executive producer of "The Ringer."

Shriver is counting on the movie to grow public acceptance and understanding of people with intellectual disabilities.

"This is a movement that people have come to trust over many, many years as being a safe place for the best of human values, a safe place for the best of human spirit ... ," he says. "So if you run around and decide to have a little fun on the set with the Farrelly brothers and throw that down the tubes, you made a big mistake."

He doesn't think he's made a mistake.

The Farrellys' intent all along, Shriver says, was to make a "transformational" comedy that alters perception of intellectual disabilities. "The risk was that you would start out with the ridicule moments, with the mockery, and have it not succeed in transforming into respect and humanization," he says. "And it would just stay at the level of trite humor."

So why risk at all? "Sixty percent of Americans say they don't want a child with special needs at their child's school," Shriver replies, doling out statistics: Worldwide, an "infinitesimal percentage" of people with intellectual disabilities get an education, a large percentage are institutionalized, a larger percentage are unemployed.

Life at the Special Olympics is not all high-fives at finish lines. "In that environment, you've got to take some chances," he says.

AN UNLIKELY MATCH

In the fall of 2000, when Peter Farrelly first telephoned him, Shriver hadn't seen any of the brothers' movies. He had somehow missed the hair-gel gag in "There's Something About Mary" and the diarrhea scene in "Dumb and Dumber."

But Shriver knew the brothers regularly wrote disabled characters into their films and often used intellectually disabled actors. And that they were often criticized for it.

"Peter approached us and said, 'I want to figure out how to take this thing on head-on and I think I've got a great script for doing it,' " recalls Shriver, who also knew the Farrellys had been participating for years in Best Buddies, a nonprofit program his younger brother, Anthony Shriver, founded in 1987 to partner volunteers with intellectually disabled people. It's where the brothers befriended Scott Gasbarro, who became a regular companion and appeared in small roles in their films.

"I grew up with a few guys in our town who had it," Peter says of his childhood in Cumberland, R.I. "What always bothered me is that any time there's been a movie with intellectual disabilities, it was sad. All the time I hung out with my guy, Scott, I don't remember ever being sad. ... I felt like nobody ever captured the fun side of being with somebody with intellectual disabilities."

"If we didn't have the Special Olympics on board, it wouldn't work because it is going to feel sneaky," Bobby Farrelly says. "And if they aren't on board, why aren't they on board? So it was kinda all or none."