Normally, “fantasies” are not the subject of water cooler banter at the office. But it’s fantasy football season—so the rules change. The challenge now is: How do you keep your staff’s fantasies from messing up the IT department’s reality? In case you’re a novice, “fantasy football uses real statistics from actual NFL players to create a points system that allows friends to compete against each another as pretend general managers of a fantasy football team,” describes Fortune. (Or, as the Huffington Post notes, it’s basically “Dungeons & Dragons for jocks.”) Often, prize money is involved. Fantasy football is big business. More than 31 million working-age Americans are involved in fantasy sports, according to the annual calculation by global outplacement consultancy Challenger, Gray & Christmas, Inc. Using figures from the Fantasy Sports Trade Association (FSTA), Americans spend about $15 billion in total playing—that’s bigger than the NFL’s annual revenue in 2013. Moreover, the average player spends three hours per week just managing his or her team, the FSTA claims. And players spend up to nine hours per week reading or watching something about fantasy sports. Organizations such as CBS Sports make it clear with products such as Office Pool Manager that they believe people are managing and researching their fantasy teams at work. There’s even fantasy football insurance. The market is so pervasive that NFL football stars have their own fantasy leagues—and sometimes they don’t even make their own teams. In response to the pressure fantasy fans place on their “players”, San Francisco 49er wide receiver Stevie Johnson Tweeted that he was starting up a “fantasy work team.” Turning the tables, he asked his followers, whom he said he’d drafted, not to let him down. But all this fantasy playing comes at a high cost. It’s estimated that fantasy football results in a loss of $14 billion in workplace productivity, based on the number of workers playing and their typical salaries, according to Challenger, Gray & Christmas. In comparison, last year’s report from the firm estimated a loss of more than $8 billion to fantasy football, with only 23 million workers playing (at a slightly lower average salary), and $6.5 billion the year before, with 22.3 million workers at a slightly lower wage. There are potential legal issues as well. “Gambling laws may be implicated if money changes hands, and employees who feel shunned or pressured to participate despite religious objections could cite those negative experiences to support a discrimination claim,” writes the Law360 blog. If fantasy players end up getting more time with their fantasy-playing boss, and as a result get better benefits, this could also lead to legal challenges. In fact, fantasy football has already been named in lawsuits. Some businesses are trying to fight back. An unscientific poll by the Orlando Business Journal found that 41 percent of responding businesses said they would not allow in-office fantasy football leagues, because they were a distraction. If you are struggling with lost productivity during fantasy football season, don’t think that you can simply ban it. As if. Plus, you may not want to, advises Challenger, Gray & Christmas. “An across-the-board ban on all fantasy football or sports websites is likely to backfire and cause a drop in morale, loyalty and, ironically, productivity,” writes John A. Challenger, the firm’s CEO. “The end result could be far worse than any loss of productivity caused by an hour or two of team management each week. Companies that not only allow workers to enjoy fantasy football, but actually encourage it by organizing a company league, are likely to see significant benefits in morale, which, in turn leads to an overall boost in productivity as well as employee retention.” In fact, 40 percent of respondents in a 2006 Ipsos survey said fantasy sports participation was a positive influence in the workplace, Challenger reports. Another 40 percent said it increases camaraderie among employees. Fantasy football could even be replacing golf as a sports-related business activity. Moreover, one in five said their involvement in fantasy sports enabled them to make a valuable business contact. “We do tons of things to encourage ‘team building’ in the workplace,” writes Suzanne Lucas for CBS Moneywatch. “In fact, many companies hire consultants or have HR teams devoted entirely to making sure departments work well together in teams. Instead of paying a consultant to come in, recognize that sometimes an activity like fantasy football can do the team building for you.” Employees are always going to have distractions, Challenger notes. “If it’s not fantasy football, it’s the latest Hollywood gossip, shopping on Amazon, or checking Facebook,” he writes. “Access to the Internet through our smartphones and tablets means that anyone can go online from anywhere. Yet, despite the growing number of distractions, the economy has not fallen to pieces.” As with “March Madness,” instead of trying to banish it, control it—set aside time and space for fantasy football, with the understanding that people will actually do their jobs the rest of the time. And obviously, watch for legal issues of inclusion, exclusion, and people who take a cut of the pot for managing it—who could be charged with being bookies. Then cheer up. It’s almost time for the World Series.