While American soldiers risk their lives in the Middle East, civilians back home are simulating virtual battles in a number of vastly popular video games.

War or conflict-based video games have been near the top of the best-selling personal computer game lists for some time.

The NPD Group's most recent weekly sales figures show that five of the top 10 bestsellers involve war or other types of violent conflict. NPD Group provides sales information to various industries so that they can optimize business.

Gerald Santoro, professor of information sciences and technology at Penn State, said video game violence is becoming more realistic and moving away from simpler Asteroids-style space fighting games.

"Is this merely taking one more step in the direction of total desensitization of violence?" Santoro asked.

There are some good reasons to play realistic video games, Santoro said.

They can help develop strategy and reaction time. Already, he said, the armed forces recruit people who show very good hand-eye coordination.

The U.S. Army has even created a conflict-based game of its own. America's Army is available for free at www.americasarmy.com.

Migdal said the Army is using the game as a recruitment tool for new soldiers.

The Army requires the gamers to go through a virtual boot camp before taking on a mission.

Video games can also offer a way to work out stress and aggression, Santoro said.

However, Mary Beth Oliver, Penn State associate professor of communications, said long-term exposure to violence is associated with desensitization.

Santoro said when it reaches a point when people start showing aberrant behavior, they need to remove themselves from that situation.

"One hopes that people realize that this is a game," Santoro said.

Santoro said gamers should at least be in their teenage years before playing more realistic simulations of violence, because children can have trouble compartmentalizing their experiences -- knowing that certain situations have certain appropriate ways of acting.

Games such as Conflict: Desert Storm, based on the first Persian Gulf War, raise questions, he said.

Because the battles happened so recently, Santoro said "it does disrespect and a disservice to anyone who was in that war on any side."

Because that conflict is now the subject of a video game, it can change perceptions of war.

"In games, there is no risk. I have no doubt there are a certain amount of people watching this conflict who view it that way," he said.

Santoro said video games should allow options for avoiding war or educating players. "If you're going to have historical wars, there should be learning," he said. "Otherwise, I'd rather shoot aliens in Halo," he said.

Oliver said war games are most enjoyed by those with strong sentiments about the war and who are favorable toward the U.S. position.

She said there is a simple reason why war games are so popular.

"We tend to enjoy entertainment where we see characters we like win and characters we don't like lose," Oliver said.

Brian Newhard (sophomore-information sciences and technology), president of the Computer Network Club (CNC), said war and combat have been themes throughout gaming history.

"It's just part of human nature to be competitive, and it's hard to get into games without a realistic component of competition," he said.

Jesse Migdal (senior-computer engineering), spokesman for the CNC, said conflict-based games of any sort are the most popular on personal computers.

Games such as the online counter-terrorism simulation Counter-Strike are popular choices for club members.

The war with Iraq has not caused a noticeable difference in the types of games people are playing, Migdal said.

"Unless the game is done well, it's not going to catch on," he said.

Santoro said people need to practice moderation and parents need to use good judgment in playing conflict-based video games.

"Part of living is learning to deal with violence. It's quite possible to play these games and not be negatively affected," he said. "It's no worse than wasting your time watching Survivor."