In the Paralympics, it's known as wheelchair rugby, but when some independent filmmakers decided to document the head-on collision sport, its freewheeling lifestyle and its goateed, tattooed star from Austin, they went with the game's original name: "Murderball."

Their documentary debuted at the recent Sundance Film Festival to packed, enthusiastic screenings and won the festival's audience award for best American documentary. Star rugger Mark Zupan was stopped on the streets of Park City, Utah, and asked for autographs and plied with business cards. He was invited to A-list parties. Film critic Roger Ebert interviewed Zupan and gave "Murderball" a thumbs-up. Sports Illustrated recently did a story on the sport and the edgy film.

The suddenly hot doc, which will be shown at the South by Southwest Film Festival on March 14, covers 2 1/2 years and culminates with the U.S. team's quest for gold in Athens at the 2004 Paralympic Games.

"When you hear 'documentary' and 'wheelchairs,' you think PBS and violins," said co-director Dana Adam Shapiro. "This is MTV and Ministry."

With his fierce goatee, large tatoos and a souped-up wheelchair that looks like a battle chariot, the 29-year-old Zupan is a compelling figure, one of three whom Shapiro and Henry Alex Rubin follow throughout the film. They show Zupan in games, at home and even at his 10-year high school reunion.

"It's about the sport, but it's also about everyday life," said Zupan, a graduate engineer at C. Faulkner Engineering. "It answers questions that people are afraid to ask, everything from getting dressed to having sex. . . . It breaks down the stereotype. We're the same as other people; we're just at a different eye line."

Co-director Rubin says "filmmakers dream of subjects" like Zupan. "He was exactly the same whether the camera was turned on or off," the director said. "He's plain-speaking and brutally honest."

Another central character is Joe Soares, a one-time American star who fell from grace with the U.S. national team and has since made coaching the Canadians — and beating the Americans — his obsession. Zupan isn't acting in the film; he really doesn't like Soares, whom many of the U.S. ruggers consider a Benedict Arnold.

"The dislike goes all the way back to when I started playing rugby," Zupan said of Soares. "He wanted to command respect, but he didn't expect to earn it."

The directors realized that they didn't have just a film about sports that would break stereotypes; they also had a classic revenge tale.

The documentary also follows someone trying to learn the ropes of life in a chair, Keith Cavill, a Moto-cross racer before his neck-breaking injury in that sport. As Zupan has said, one of the things that makes quad rugby interesting is that everyone has a story, a day or a life-altering moment where a crash or fall put them in a chair forever.

Zupan was a soccer player when friend Chris Igoe, not knowing Zupan was passed out in his truck bed, spun out and slung Zupan into a roadside canal in Florida. Igoe, unaware of what had happened, then sped off. The injured Zupan somehow clung doggedly to a tree throughout the night. By the next day his core body temperature had plunged and little more than his lips and mouth were above water. Luckily, a worker at a nearby office building somehow spotted him while eating lunch in his car.

When most people hear the word "quadriplegic," Zupan said, they think of the late Christopher Reeve, who fit the Webster's Dictionary definition of quadriplegia as "total paralysis of the body from the neck on down."

Reeve, however, had the most severe form of quadriplegia. Others who suffer broken necks can retain some use of their limbs.

For quad rugby, players must have a combination of upper and lower extremity impairment. The players are rated according to the use they have of their limbs, anywhere from a low of 0.5 to 3.5. Four players per team are on the basketball court-sized floor at one time and each side cannot have a combined rating of more than 8.0.

The object is to get the ball across a goal line, or stop the other team from doing that, and the collisions can send players flying out of their chairs. The action and the gym-rattling noise makes for dynamic competition and drama.

Shapiro and Rubin began following the U.S. team at the 2002 Wheelchair Rugby Championships in Sweden. The storyline led to Austin, where Zupan is part of the national championship club team, the Texas Stampede, put together by James Gumbert.

"We've had guys follow us around before with cameras and nothing ever came of it," Gumbert said. "It just gets to the point of, 'Sure, whatever.' But these guys turned out to be the real deal."

The film's climax comes at the Athens games with a game against the Canadians, but there are several subplots. One is the reconciliation of Zupan and Igoe, who even goes to Athens to cheer on the team.

"The movie was definitely a catalyst. It changed lives," Shapiro said.

For Zupan it has certainly created a new role, film star.