You don't want to get hit in the neck. Not only is there little flesh to absorb the shock, but the hit leaves a mark of distinction.

"Kind of like a hickey," says D.C. Arsenal's Sean Henderson, whose paintball bullet memory is imprinted firmly in his left shoulder.

For most, it's unavoidable to be hit by a round capsule filled with a soapy-tasting, colored liquid. And while the aim of paintball is to avoid these markings, the scars -- and bruises in every possible shade of yellow and purple -- are part of the game.

The Sporting Goods Manufacturing Association reported that 9.6 million Americans played paintball at least once in 2004, almost double the number in 1998. Chuck Hendsch, president of the National Professional Paintball League (NPPL), estimates the number is a little higher now -- up to 11 million in the United States. Hendsch said ESPN2's broadcast of the 2005 U.S. National Paintball Championship has helped increase the sport's popularity, though the NPPL has not had any of its events televised this year.

The game also has changed from its camouflage roots to an indoor, spectator-style sport.

"We're out of the woods now, and we're competing for money," said D.C. Arsenal captain J.C. Whittington.

First, there are technological improvements. Semi-automatic guns used by pro teams can shoot up to 30 paintballs per second, though most shoot 15 to 16 per second; the shots travel 300 feet per second (more than 200 mph). Then there are the sponsorship deals, where professional players average $30,000 a year.

Finally, there's the celebrity.

"It's a rock star lifestyle," said Whittington, whose itinerary reads like a world-class tour.

D.C. Arsenal has traveled to France, Germany, Sweden, Spain, Italy, the Netherlands, England and Portugal. The team arrives early to canvass the turf and plot their way around a series of bunkers. Its games are seven-minute stints where the aim is to capture an opponent's flag.

After events in Huntington Beach, Calif., and Tampa, Arsenal is ranked 13th in the 18-team NPPL. Team member Mikey Salas said Arsenal has to get itself together and start strong.

"The first five seconds are the most crucial," Salas said.

It's within those initial moments that the adrenaline kicks in.

"It's the thrill of playing for your life. If you get shot you can't play anymore. And you definitely know you got shot," said Salas of feeling the bullet's impact.

And those shots -- like the scar on the knuckle of Salas's middle right finger -- aren't easily forgotten.