KIGALI, Rwanda — Game day. Sam Dargan, 29, a four-year veteran of the nascent sport known as moto-polo, awoke early — or relatively early, for a Saturday in East Africa — and began the traditional routine.

Fire up the stoves; let the chapati, banana and beans stew nicely. Wrap the mallet; duct tape works best. Check with your partner; be sure to arrive on time. Jon Stever, a teammate from Texas, is coming over with the truck and the pig to roast after the game. And do not forget the beer.

Motorcycle polo has only a few dozen dedicated practitioners here, but they are convinced the sport is destined for widespread popularity. Because who can resist an activity that combines single-cylinder engines, mallets and beer?

It is similar to traditional polo, except it was born out of this country's distinctive palette of characters, customs and resources.

Instead of horses, of which there are few in Rwanda, players drive and ride motorcycles, of which there are many. Along the slick roads here, in Rwanda's capital, they are commonly used as taxis, and a growing number of young Rwandan motorcyclists turn up at competitions to show off and practice their skills.

The game has few rules. There are five players a team, opposing goals and 15-minute quarters with a "beer's worth" break in between. The game is played at a frenzy — drivers goose the bikes to 45 miles per hour — as players jab and motorcycles fall. Spectators crowd as arguments ensue.

"I play with no fear," said Chameleon Ngirimana, widely regarded as one of the sport's best players.

The game has spread to neighboring Uganda, and a team from Rwanda is scheduled to play there.

On a sunny Saturday at the field by the airport in Kigali, scores gathered to watch a recent match, a doubleheader, beginning with a rivalry between North and South United States.

A formal schedule for moto-polo matches in Rwanda has not been established, and this one had the feel of a picnic, with spectators splayed on hoods and tops of automobiles, while cold beers were sold out back.

Moto-polo's top players and pioneers assembled on the field — Dargan, Stever, Timote Niyomugabo, Margaret Vernon, Ngirimana — settling on a steely regiment of TVS 125cc road bikes. Some were dressed to the nines, in comedic costumes or high fashion.

The referee waded out to midfield, carrying the signature banana-leaf ball, as a crowd of expatriates and Africans gathered near the sidelines and on a nearby hill. Drivers revved their engines. Then the ball was dropped.

Dargan, from South Carolina, and his South teammate Matt Smith, from Texas, said they created moto-polo in the summer of 2008. Rwanda, a tiny land of sun-kissed hills, is conducive to such recreational innovation.

As Smith describes it, he and Dargan, who runs a solar power business here, had hired a motorcycle-taxi that day for the receiver to ride on when they had the idea.

"I was explaining to him donkey basketball, something that you play where I am from," said Smith, who works in Rwanda's coffee industry. "We were thinking donkey polo, but then we realized there are no donkeys in Rwanda."

Smith and Dargan began doing research and found a lost trove of history. A newspaper article from 1912 described a sport called auto-polo that was played across the United States as automobiles became popular. Variations bubbled up for several decades.

"Then there is no trace," Smith said, "for 60, 70 years."

The first moto-polo match in Kigali was filmed and posted on YouTube in 2008.

"Very interesting, very amazing, very surprising," said Augustin Bizimungu, 54, a pedestrian passing atop a hill overlooking the soccer field, where the South had taken a 3-1 lead. "I didn't know people can play this game."

The sport is evolving. Official statistics are not tabulated. Rules have never been written and are generally thought to be limited to these: motorcyclists cannot use their feet to kick the ball, and players cannot stick objects into motorcycle wheels — "the Indiana Jones rule," Stever said.

"It's never actually happened, but it's the first rule we came up with," he said.

East Africa is a rising economic and political bloc, and expatriates and East Africans alike travel frequently around the region. Despite the small pool of players in Rwanda, the game could spread. When one of the original moto-polo players moved to Kampala, the capital of Uganda some 230 miles away, he took the sport with him.

The first match in Uganda, held last year, also served as a fund-raiser to help pay the legal fees of Ugandan women sexually trafficked to Iraq.

Back in Rwanda, the drivers are paid $20 for an hourlong game in a country where the average daily income is a little more than $3, according to the World Factbook, a Central Intelligence Agency publication. All damages to motorcycles sustained during matches are paid for by the organizers.

"I don't know how I can tell you, but this game is so fun," Ngirimana said during a break after the third quarter. "First, we came for the money; now we just like it."

Local residents typically drive the motorcycles, and expatriates ride on back wielding mallets and scoring goals. The ones in control of the machine are considered more important to a winning team.

"Only a few can take the ball all the way downfield," said Stever, who added that he would arm-wrestle someone for the chance to ride with Ngirimana. "He's just superaggressive."

So is Dargan, who wound up his mallet, with his motorcycle facing the opposite direction, to score an around-the-back goal just as time expired, giving him a hat trick. South won, 7-2. Beer time.

This article has been revised to reflect the following correction:

Correction: May 9, 2012

A caption with a slide show displayed with an earlier version of this article identified the wrong person and gave the wrong creator of motorcycle polo. The person in the photograph is James Dargan, not his brother Sam Dargan, who the article correctly identifies as a co-creator of the game.