Wouldn’t it be great if some of the real world could be altered to better suit you personally? Forget the easy stuff like changing the weather or moving a mountain range. Imagine having creative control over your own personal entertainment! Supervisor giving you the runaround? Replace him with a sentient tree. Why not? PC game developers have been doing this for years, substituting certain variables with other, more attractive, variables. Whether a mod makes small changes for the better or completely reinvents the game, mods are the developer’s way of saying, “Let me fix that for you.”

Some of your favorite (your favorite) games began their existence as mods. The ever-popular and hemorrhage-inducing multiplayer online first-person shooter Counter-Strike may never have existed if it weren’t for its grandpappy Half-Life. Valve Corporation encouraged at-home developers to tinker with their source code, and lo, a baby was born that has consumed many hours for would-be terrorists or anti-terrorists.

Even your precious Team Fortress 2 — a team-based shooter pitting varying characters with varying jobs against each other in a fast and furious violence-packed battle royal — has its roots in ye olde Quake, a game my grandma played while waiting for her cucumbers to pickle.

But as with all things — all things — there is a virus that will corrupt it. There is no cure. There is no hope. At some point, a zombie will show up in your mod. Zombies are the pet rocks, pogs, slap bracelets and Pokemon of our generation. Valve’s Left 4 Dead, the four-person zombie survivalist wet dream, kicked off the zombie game revolution, and it’s been spreading out of control ever since.

Take DayZ for instance, a modification to an otherwise obscure open world first-person shooter from Bohemia Interactive based in Hungary. ARMA 2, a generic wartime battle simulator, made a small splash when it was tossed into the pool of war-based gaming, but when Dean Hall — a developer working for Bohemia — thought to himself that the game could use more zombies, a mod baby was born.

DayZ imagines a zombie apocalypse as a zombie apocalypse might really happen. Your character is on an island — a very large island — and there are zombies. That’s a given. What isn’t is the realistic way in which it’s all presented: you must have food and water, there are no maps or beacons to tell you which way to go, and there are other survivors — real people playing at the same time — who may help you or may kill you and take your things. When you die, you are dead; game over, man. Game over. (Until you start up a new character, sans all of the things you may have collected.)

If this sounds ridiculously hard, it is. It can also be a little vague in purpose — as in, there is no purpose but to survive, which makes it amazing. Left 4 Dead had obvious goals: get to point B from point A. DayZ has none of that. DayZ is the game that crosses the boundary of reality and fiction, melding the two into a realistic experience.

Imagine taking a stroll to the end of the Ventura Pier. The sky’s clear, the waves are gentle, a fisherman catches a local Ventura sea creature and reels it in, hoping that it isn’t a boot. The salty air fills your lungs and you smile, only to turn around and see that the fisherman has caught himself a zombie! Somehow, on your short trip, the entirety of Ventura has been overrun and it’s up to you to survive, with only a few tins of beans and tap water to sustain you.

See? I just modded Ventura. DayZ is the closest you’ll come to an actual outbreak, with the exception of an unlucky fisherman’s catch of the century. DayZ is readily available as a modification to ARMA 2, which is available for the PC for $29.99.

Chris O’Neal isn’t the writer that you need right now, but he’s the one you deserve. Follow him on Twitter @agentoneal and at www.allthepretty.com.