DayZ places the player on a beach in the fictional post-soviet state of Chernarus, where an unknown virus has turned the general population into savage infected, who have devastated the CDF. As a survivor with limited supplies, the player must search the world for supplies such as food, water, weapons and medicine, while killing or avoiding both zombies and other players - in an effort to survive the zombie apocalypse.
The game attempts to portray an authentic scenario, with the environment having many different effects on the player. A player may receive bone fractures from repeated damage to the legs, go into shock from unexpected ambushes, receive infections from both infected zombies or diseased players, or even spontaneously faint due to a low blood pressure. Thirst and hunger must be regularly dealt with by finding sustenance in either cities or in the wilderness, with body temperature playing another key part in the character's survival.
The Zombies of DayZ are fast, and will chase the player indefinitely, but cannot close pursuit on an able bodied survivor. Zombies appear in three basic varieties, runners, kneelers, and crawlers/slitherers. Much like Left 4 Dead, a player cannot be infected and transform into a zombie (One can catch and transmit a regular flu, however). They are durable, and require many shots from handguns to put down (except for headshots and axe blows, which are instant kills). They are also fairly easy to sneak past, and can be distracted by thrown objects.
Dean Hall created the concept while he was a soldier in the New Zealand Army; as a suggestion for training soldiers through exposure to situations provoking emotion and relevant thought processes. He has stated he was inspired by experiences during jungle training while on exchange with the Singapore Armed Forces in Brunei, where he was badly injured in a survival exercise. Hall has stated that his experiences in the New Zealand Army directly affected the development of the DayZ mod, and the creation of immersion through forcing the player to experience emotion and tension as part of gameplay. Hall believed that early rapid success of the mod was largely due to social media and consumers desire for games that provided significant challenge. Hall has described the mod as something of an "anti-game" as it broke what he felt were generally considered to be basic rules of game design such as balance and not frustrating users.
The mod has garnered a large user base due to its unique gameplay. By August 2012, three months after release, the mod had registered more than 980,000 unique users, according to the mod's official website. The installation has since been made a lot easier with use of third-party software, Six. The mod has become extremely popular, receiving wide media attention. The mod is currently in Alpha.
The developer of ARMA 2, Bohemia Interactive, praised the mod with CEO Marek Spanel saying the mod creates an addictive and thrilling experience, believing that it could stand as a gaming experience on its own, and saying the mod was directly driving sales of the game.The mod also received praise from video game developers not involved with the series.
Wired said it could well be the most terrifying game of 2012, and Rock Paper Shotgun reporter Jim Rossignol praised it as the best game he had played so far in 2012. Kotaku described it as possibly the greatest zombie game ever made, and said it was the most interesting PC game of 2012. The mod has been compared to The Walking Dead and its focus on interactions between the characters when faced with their desperate situation, with the players in DayZ forced to deal with dilemmas in similar ways as portrayed in both the comics and TV series for the franchise. Bit-tech stated that no other game in the genre has offered such a compelling take on a zombie apocalypse, and compared the impact of the mod on the industry to that of Defense of the Ancients and Counter-Strike. PCGamer widely praised the game, stating it was one of the most important things to happen to PC Gaming in 2012.