Though the wound was gushing with blood, I couldn't stop. I had to keep on running. Gravel and dirt were crunched into a fine mist underneath my tireless feet. The siren call of the undead was nearly impossible to ignore, even amid my own desperate gasps for air. Colors faded away as my vision blurred, and I lost all sense of direction. My world was rapidly careening into madness, and it wasn't long until my body collapsed from sheer exhaustion.

The relentless pursuers had finally caught their prey.

Such is the harsh world of DayZ, a zombie mod for Bohemia Interactive's three-year old military simulator, ARMA II, and its 2010 expansion, ARMA II: Operation Arrowhead. Solely developed by Dean Hall (who now works for Bohemia), this multiplayer-only, open-world zombie mod is nothing like you've played before, placing emphasis on realistic survival mechanisms rather than just being a mere shooting gallery. The mod's player base has grown exponentially in the last couple of weeks due to positive word of mouth from both fans and mainstream sites alike. Because of this recent popularity, ARMA II: Combined Operations now sits comfortably near the top of the selling charts on Steam.

So what makes this mod so special? Well for one thing, the shambling corpses aren't the only threat you'll encounter. You'll have to contend with other survivors (up to 50 on a given server) who might or might not help you out in your quest for supplies. When you first spawn into the fictional post-Soviet state of Chernarus, you're given a modest amount of ammo, food, and medicine to start you off, but beware, these things alone are enough to make you a walking target to anyone who might cross your path.

Generally, these players would be identified as “bandits” with their own custom skin to label them as such, but this is not always the case. Even if you call yourself out as being “friendly” in the public chat, other survivors will not hesitate to murder you. In one particularly painful sequence, I had been silently foraging a town for loot for more than two hours when two survivors got the drop on me and placed a well-aimed bullet into my skull.

So, just like the real world, DayZ can be heartless. Once you die, everything in your inventory is lost, and you'll have to start all over again. It's this constant risk and reward gameplay that keeps players coming back.

It's not all doom and gloom, however -- a few brave souls are out there willing to work together if only to scare off any bandits looking to hunt down lone survivors. Before my gruesome murder, I teamed up with another player who happened to spawn near me, and we decided to investigate one of the game's many towns. More so than the countryside, towns are crawling with dozens of zombies, and it definitely helps to tackle them with other people by your side.  

At one point, I ran out of bullets, leaving me completely unable to defend myself (the mod currently does not have any form of melee combat). My partner had to take the lead as we continued to search the town, and unfortunately, we didn't find any ammo in a sea of canned beans and bandages. Rather than just try to defend ourselves with one gun, he decided to make the ultimate sacrifice. He intentionally killed himself, so I could loot his body for his remaining clips and other goods, even if it meant he would randomly respawn in another area of the 225 square-kilometer map.

DayZ isn't perfect. Lag can frequently become an issue, character animations look goofy, glitches of various types abound, and the server connections are inconsistent at best. But for something that's still in alpha, it still manages to deliver a very compelling and memorable experience. You can do so much -- rebuilding vehicles, chopping wood for fire, hunting animals for meat, defending a town from bandits. And you have to deal with so many unknown variables (try playing in the pitch black darkness at night for extra scares) that every playthrough is guaranteed to be different from the rest.

In light of recent events, the zombie apocalypse might be happening after all. So why not develop those survival skills by playing DayZ? I promise I won't shoot you.  

In order to play the DayZ mod, you must own ARMA II: Combined Operations, which includes both the original game and its expansion. You can download the mod on the official DayZ site.