People like violence, regardless of the medium it’s delivered in. It’s why traffic slows down near car accidents, why the highest grossing films are often graphic and why the most popular video games are violent.

In fact, with the notable exceptions of “Tetris” and “Nintendogs,” all of the top 20 best-selling games of all time have some violent aspect to it. It seems obvious people like to not only watch violence happen, but do it themselves. Since morality and the law get in the way of acting on such urges, video games turn out to be the best and most efficient way of quelling them.

One of the most effective ways to cause as much mayhem as possible, in as little time as possible, would be to play a game about shooting zombies. In Valve’s “Left 4 Dead 2,” the player literally blows apart zombies by the hundreds; by the end of a level, it’s very possible the player could be soaked in zombie blood.

It’s important to note “Left 4 Dead 2” did not receive any criticism in the U.S. for killing truckloads of zombies. However, “Call of Duty: Modern Warfare 2,” which was released near the same time as “Left 4 Dead 2,” was heavily criticized for a level called “No Russian.” In it, the player is an undercover CIA operative infiltrating a Russian terrorist organization, and to gain the leader’s trust, the player must join him in killing all the civilians in a Russian airport.

The developer, Infinity Ward, included precautions to stave off such criticisms such as allowing the player to skip the level entirely and not forcing the player to actually shoot any civilians. Yet, publications like the Salt Lake Tribune criticized the game for not being responsible enough in the game’s depiction of violence.

“Left 4 Dead’s” zombies and “Modern Warfare’s” civilians are very similar: The player can kill dozens of them, they look and act like people and none of them talk. The only difference between the two groups is how the player is supposed to perceive them.

Zombies are supposed to be viewed as brainless, hostile and incredibly deadly while the civilians in the airport are to be viewed as defenseless, peaceful, and not a threat to the player whatsoever.

This perspective is not only the source of “Modern Warfare’s” controversy, but the appeal of zombies as they appear in video games. People want to feel as if they are part of a small group against the mindless hordes. This is why zombie games and films usually keep the group of main characters less than 10 people.

People like to feel as if they’re fighting against an absolute evil no one in their right mind would join, and zombies fulfill this requirement beautifully. A ravenous, unquenchable urge to destroy all sentient life is something nearly everyone can hate and fight against.

That’s just one reason for zombie popularity, though not necessarily the strongest. Remember, people like violence, especially when it happens to someone else they do not have any emotional connection to, hence the rubbernecking at car accidents.

Zombies are always anonymous, except in rare occasions. When people play “Left 4 Dead 2,” they never encounter any corpses, walking or otherwise, that any of the four main characters know. Making all the zombies anonymous allows the player to kill them without any moral problems to debate, but only as long as the player knows the enemies are zombies. Even though the civilians in “Modern Warfare’s” airport are also anonymous, there are huge moral problems to killing them.

To create an appealing zombie video game, the zombies must have both an uncontrollable urge to destroy and anonymity. As long as the audience sees both characteristics work together, the zombies will be perceived as genuine.

Nick can be reached at: [email protected]