Laura Holshouser's favorite video games include Halo, Tetris, and an online training game developed by her employer. A training game? That's right. The 24-year-old graduate student, who manages a Cold Stone Creamery ice-cream store in Riverside, Calif. , stumbled across the game on the corporate Web site in October. It teaches portion control and customer service in a cartoon-like simulation of a Cold Stone store. Players scoop cones against the clock and try to avoid serving too much ice cream. The company says more than 8,000 employees, or about 30% of the total, voluntarily downloaded the game in the first week. 'It's so much fun,' says Holshouser. 'I e-mailed it to everyone at work.' The military has used video games as a training tool since the 1980s. Now the practice is catching on with companies, too, ranging from Cold Stone to Cisco Systems Inc. to Canon Inc. Corporate trainers are betting that games' interactivity and fun will hook young, media-savvy employees like Holshouser and help them grasp and retain sales, technical, and management skills. 'Video games teach resource management, collaboration, critical thinking, and tolerance for failure,' says Ben Sawyer, who runs Digitalmill Inc. , a game consultancy in Portland, Me. The market for corporate training games is small but it's growing fast. Sawyer estimates that such games make up 15% of the 'serious,' or nonentertainment market, which also includes educational and medical training products. Over the next five years, Sawyer sees the serious-games market more than doubling, to $100 million, with trainers accounting for nearly a third of that. It's numbers like those that prompted Cyberlore Studios Inc. , maker of Playboy: The Mansion, to refocus on training games—albeit based on its Playboy title. And training games will be top of mind at the Game Developers Conference in San Jose, Calif. , this month. Companies like video games because they are cost-effective. Why pay for someone to fly to a central training campus when you can just plunk them down in front of a computer? Even better, employees often play the games at home on their own time. Besides, by industry standards, training games are cheap to make. A typical military game costs up to $10 million, while sophisticated entertainment games can cost twice that. Since the corporate variety don't require dramatic, warlike explosions or complex 3D graphics, they cost a lot less. BreakAway Games Ltd., which designs simulation games for the military, is finishing its first corporate product, V-bank, to train bank auditors. Its budget? Just $500,000. Games are especially well-suited to training technicians. In one used by Canon, repairmen must drag and drop parts into the right spot on a copier. As in the board game Operation, a light flashes and a buzzer sounds if the repairman gets it wrong. Workers who played the game showed a 5% to 8% improvement in their training scores compared with older training techniques such as manuals, says Chuck Reinders, who trains technical support staff at Canon. This spring, the company will unveil 11 new training games. Games are also being developed to help teach customer service workers to be more empathetic. Cyberlore, now rechristened Minerva Software Inc. , is developing a training tool for a retailer by rejiggering its Playboy Mansion game. In the original, guests had to persuade models to pose topless. The new game requires players to use the art of persuasion to sell products, and simulates a store, down to the carpet and point-of-purchase display details. Don Field, director of certifications at Cisco, says games won't entirely replace traditional training methods such as videos and classes. But he says they should be part of the toolbox. Last year, Cisco rolled out six new training games—some of them designed to teach technicians how to build a computer network. It's hard to imagine a drier subject. No