Before I begin, permit me to say that this is not DayZ; this is a mod based on DayZ. Yes that does mean it's a mod of a mod, but this no-nonsense post-Soviet zombie survival game is all the better for it.
DayZero is a free-to-play online multiplayer mod for ARMA 2 (requires Operation Arrowhead) which is basically a game in its own right. I've lost many an hour/day to the simplistically brilliant gameplay of this virtual human drama, and I've never regretted it. It's by far the most thrilling game I've ever played. Here's why.
Then you hear a gunshot from the trees and a .303 round whizzes past your face, it splices the air in twain with a crack that simultaneously deafens you and makes you soil yourself. Then it hits you, like that rifle round was supposed to; you've landed in Chernarus.
Chernarus, for those of you unfamiliar with it, is a charming location on the northern coast of the Black Sea, in the armpit of the former Soviet Union. For reasons unknown, it (along with most of the world) has been plagued by an infection that has turned the country's hospitable populace into a rabble of mindless drones with an appetite for us humans. Luckily for you (and everyone else on the server), you're immune to this infection for some reason. Yet because you're immune to it, and there's no cure, you're sole purpose in life now is to try and survive for as long as possible in this Eastern European wilderness populated by zombies, gun-toting madmen, and fellow survivors.
Yet however important drink, food, and firearms may be, its a necessity above all else to keep your backpack stocked with medical supplies. If you get shot up by someone, or maimed by a zombie, chances are your going to succumb to shock, which makes your head constantly shake in time with your pulse, making it incredibly difficult to aim. For that you need a hefty amount of painkillers. After that, lets say you accidentally fall off a roof (or it may be deliberate, depending on the scenario), and you injure one of your legs: you can't walk, and unless you have a shot of morphine handy, you're going to spend the rest of your imminently-ending life crawling through the dirt. In another unfortunate circumstance, you may find yourself bleeding profusely, and without any bandages to stop it, that wound is going to be the death of you, unless you come across some in a house at the last minute, and save yourself with moments to spare. Then another triad of problems may present itself; your blood level is so low now that your head is pulsating violently, you're prone to fainting every other minute, you've lost all concept of colour, and you're about 90% blind. On top of all this, the nearest hospital is 5km away, and the chance of there even being any blood bags there to replenish your blood levels is very slim. On the plus side, your companion does have an epi-pen on him, so if you do pass out at least he can revive you. Medical supplies are vital.
You may be wondering though, now that I've basically finished explaining to you what DayZ is, "why DayZero in
particular?". DayZero is, like I said at the start, an off-shoot of DayZ. It's set in the same location, with the same environment, the same goals, and the same mechanics for the most part, yet DayZero triumphs over DayZ in the smaller things. Performance, -both in game and at the servers' end-, is a lot more fluid, zombie AI is less buggy, weapons are improved both in characteristics and audio, and vehicles are more of an advantage than a liability. Perhaps the most important part though is the community. I find DayZero is a lot more active than DayZ, and the people that play it are more open to the experiences they encounter in the game world. Whether you're helping a struggling Norwegian chap with broken legs and very little blood get back on his feet, or negotiating your way out of an impasse in an old castle, players are more talk-first-shoot-second and less shoot-and-say-nothing-at-all.
At the end of the day though, its the experience that maketh the game for me, and the experiences found in DayZ/DayZero are so enthralling that Bohemia Interactive commissioned the lead developer to transform it into a standalone game, though that's a story for another day...
ARMA 2: Combined Operations is available on Steam for £16.99 (but it'll be on sale again before you know it), and DayZero is downloadable from zombies.nu and also from the equally downloadable DayZ Commander launcher programme.