Imagine the world were overrun with zombies.

For students and members of the UT Humans vs. Zombies club, this train of thought has been their central focus from the beginning.

Gaining traction at universities, military bases and camps around the world, HvZ is currently played at almost 650 universities on six continents. An intensified version of tag, HvZ is the safest way to experience a zombie apocalypse.

Each semester, HvZ organizes two week-long games and two shorter, one-day events.

"Everyone starts as a human, except a small group of original zombies," said Adam Howard, president of the HvZ club. "The goal for the human team is to go the whole week without getting tagged and the goal for the zombies is to tag as many humans as possible."

Armed with Nerf Blasters and socks, humans attempt to "stun" the enemy hoard. Howard, junior in engineering, said many of the club members get intense about the game.

"The survivalist types aren't quite crazy," he said. "But they are really into the game, given the sheer amount of money they spend on Nerf weaponry."

HvZ is a game that will appeal to students who have a competitive and adventurous side, according to Katherine Cahill, senior in English who joined HvZ last spring.

"You get that rush of adrenaline that you wouldn't normally get when walking from class to class," Cahill said. "It's just a chance to do something different. It's kind of breaking social norms in a way, which is liberating."

The group uses the Internet to conduct missions, work out strategies and communicate within teams. Players on the zombie team log each "kill" they make on the HvZ website. Humans can use the message boards to organize and plot against their undead rivals.

HvZ moderators, called "mods" for short, regulate the game and handle the club's administrative tasks. The mods do their best to make sure participants get the most out of the game.

"The way we make sure the humans don't just hide in their rooms or something is by planning missions," Howard said. "A mission is typically some kind of activity that the mod team comes up with, like finding a certain amount of an item we've hidden around campus. We try to come up with things that are unique and original."

There is no set time commitment for members of HvZ. Participants are encouraged to take an active role in the game and go on the nightly missions, but the level of involvement is ultimately their choice.

"It just depends on what you have time for and are willing to commit to," Cahill said. "You can decide to spend more time outside between classes trying to tag people if you're a zombie or you can hold yourself up in your room and survive, but you're not really having any fun that way."

Since the founding of the club in 2011, the group's demographic has diversified greatly.

"When we started, our demographic was basically made up of just male freshman engineers like me," Howard said. "But over time, it's branched out a lot. Now we have people from ROTC, architecture students and art majors. And now about 30 to 40 percent of our members are female."

Zombies are increasingly seen in popular culture, exhibited by the commercial success of television shows like "The Walking Dead."

"Zombie culture has been around since the early 20th century and it's been escalating ever since," said Michael Miceli, junior in linguistics, who joined HvZ after hearing about the game from a friend at University of Maryland. "Video games like 'Call of Duty' and books like 'World War Z' have really made zombies more widespread and popular."

While some are enthusiastic about the rise of the zombie, others are just happy to see certain imaginary creatures driven out of mainstream culture.

"I think the whole zombie trend is kind of annoying," said Russell Fulcher, freshman in forestry. "But, really, anything is better than vampires. And running around with Nerf guns sounds about as good as it gets, so I'd be open to playing Humans vs. Zombies."

Like many UT students, Fulcher had never heard of the relatively new HvZ group. The club is easy to join and the game is free to play. The only requirement is attendance at a registration meeting.

"There are registration meetings that you have to go to because we have to cover safety briefings, university rules and the guidelines of how to play," Howard said. "But if you happen to be walking around and see someone with a strip of green tied around their arm or head, just go talk to them. I will sign you up for the game right there on the spot and maybe even give you a spare Nerf gun."

The first one-day mini-game for this semester is scheduled for Sept. 14. Students interested in participating in the week-long event that will occur Sept. 17-21 can attend a registration meeting on Sept. 16.

For more information on HvZ events and announcements, like the Humans vs. Zombies Club at UTK Facebook page here.