At the 17th hole on Kiawah Island Golf Resort's challenging Ocean Course, the foursome paused. The Atlantic Ocean can be seen from many of the raised greens, but on this hole, all eyes were on an adjacent pond—and its resident alligator. Chad Nelson joked to YuChiang Cheng that a Kiawah pro had suggested not going after any lost balls, then pulled out a 3-wood and chipped his over the drink. Cheng followed suit.

Cheng, C.E.O. of San Francisco-based videogame maker World Golf Tour, has never been to South Carolina. But he's played Ocean Course hundreds of times. It is one of dozens of premier resorts that the start-up has recreated in what the founders call "2 ½-D" in an effort to become a new gaming heavyweight.

For years, the virtual-golf scene has been dominated by Electronic Arts, the world's largest independent game publisher. E.A. Sports' Tiger Woods PGA Tour franchise has sold more than 26 million copies since it was first released in 1998. Much like Woods, it has squashed the competition: Microsoft's Links franchise, which started in 1990, shut down after five years against E.A. And in addition to locking up Woods, E.A. Sports holds the exclusive license for the P.G.A. Tour, essentially shutting out other comers—until now.

World Golf Tour is trying to sidestep the roadblocks. It's cutting individual deals with top golf courses so that it doesn't need to deal with the P.G.A. Tour. The stars of its greens will not be pro golfers, but players' avatars. And it is making the games in Flash, so they will be available to a far wider audience of players—for free.   

Nelson, World Golf Tour's president and co-founder, conceived the game in early 2006 while golfing in Italy. He and Cheng had sold their PC game-development studio, WagerWorks, to IGT for $90 million the year before, and he wondered why there were no good online golf games.

Since the pair knew they didn't want to be just another game developer, they decided to come up with a new business model, one that would combine online distribution, advertising opportunities, and virtual sale items. And the game couldn't be like its predecessors—Flash-based golf experiences at the time were like the miniature golf of videogames.

"We're going for a true golf simulation," Nelson says. "Things like course management—where you place the ball, type of clubs and stance you use, how you use spin control—has an impact on the game."

In October 2007, the company unleashed a dozen technicians, programmers, and photographers onto Kiawah's Ocean Course, to meticulously record the layouts with digital photography on the ground and in the air (using remote drones and full-size helicopters), G.P.S. technology, and terrain mapping. The company had a pair of ex-Electronic Arts programmers build an online physics engine to replicate the way balls roll across different surfaces; hundreds of high-definition digital photographs (an average of 700 per hole) layered atop a 3-D map allows balls to "bounce" and "roll"—paving the way for golfers to experiment with shots virtually before trying them for real.