Raymond Tyson is in the thick of battle. Beads of sweat form on his forehead as he lurches to swat a Ping-Pong ball. Tim Sherrill returns the volley, but Tyson goes on to win the 30-minute game, 21-19.

The game over, the two put up their paddles and return to work.Just a typical lunch break at EMJ America, a computer distribution business in Apex, N.C., where workers can play games before, after or during work.

Board games are not the only diversion. Workers can play volleyball or jump on a large trampoline behind the old brick school that houses the company. Every afternoon, a high-energy group of EMJ employees, garbed in T-shirts and shorts, kicks and punches to a Tae-Bo video in an open space that's being turned into a gym for basketball, racquetball and weights.

''It's not your typical corporate America,'' said Tyson, 38, a shipping and receiving manager, who said the games are a stress-breaking respite from packing boxes with computer software and hardware. ''One of the reasons why I've been here is because of the relaxed atmosphere. Once you get all of the frustrations out, you're ready to work. You see people with their guard down. You see them relaxed.''

Work and fun are rarely considered synonymous or even complementary, but more employers are encouraging fun in an effort to boost production. Attempts range from the subtle, such as casual dress, birthday parties and funny art on walls, to the silly, such as team Nerf-gun fights, stump-the-CEO contests and relay races in office chairs.

Loosening up the office is not a waste of time, managers say. In a recent national survey of 286 employers, 55 percent said fun and humor ease workplace stress; 34 percent said fun boosts job satisfaction; and 28 percent said it improves creativity, according to William M. Mercer, a human-resources consulting firm.

Adding fun to the workplace is like putting the icing on a cake, said Leslie Yerkes, a management consultant in Cleveland and co-author of ''301 Ways to Have Fun at Work'' (Berrett-Koehler). Companies enhance their services and morale when they make training, meetings and work more enjoyable. And workers who enjoy their jobs tend to be more productive rather than slacking off.

''One of the greatest challenges is finding and keeping good people,'' Yerkes said. ''We spend more time at work than anywhere else in the world, so why would we not seek a workplace where work is fun? The fun is integrated into the work. If you've found the right people and you trust them with your company's most important assets, why would you not trust these same people to use their judgment about what's too much fun?''

The idea of incorporating games has been embraced by many technology companies, which tend to have young staffs - and CEOs - who work long hours. But high-tech firms are not the only businesses to realize the value of the occasional pastime.

The regular Shakespeare festivals at Tharrington Smith, a Raleigh law firm, have been a dramatic hit with employees, said criminal defense attorney Wade Smith. A few years ago, the firm came up with the idea of picking a play a year by the English bard and distributing copies to all employees. Employees are given about a month to read the play, chosen by Edmund Fuller, an 84-year-old Shakespearean scholar from Chapel Hill. Fuller is then invited to lead a lecture sprinkled with colorful orations.

''It's fun, and life should be fun, and work should be fun,'' Smith said. ''We should do all that we can in the workplace to make people happy and to enrich their lives.

''We work hard to make this a place people look forward to in the morning. If you enjoy work, you are healthy, you live longer, you are kinder to your family. From happy work, great things flow.''

That philosophy could apply to Peter Heffring, president of Ceres Integrated Solutions, a software company in Raleigh. To make the 60- to 70-hour workweeks more palatable, the business gives away tickets to concerts and hockey tickets, and puts stereos in every office. Every two weeks, $1,000 is spent on any kind of food that workers want, from cashew nuts to M&Ms.

Employees who win a quarterly award for work performance are sent to a three-day car-racing school in Savannah, Ga. (Heffring's hobby is racing.)

Ceres product specialist Kim Karriker said her company's playful perks make her feel more appreciated. She works hard, but she looks forward to coming to the office, she said. In her first eight months at the company, she has received free tickets for concerts by Hootie and the Blowfish and Patti LaBelle.

''This has been the most generous company I've ever worked for,'' said Karriker, who said she's in her early 30s. ''Everyone seems to have the basic concept that it's the hardest they've every worked, but they love it.''