Open-world zombie survival game DayZ has sold over three million copies since launch in December 2013, according to developer Bohemia Interactive. It sold one million copies during its first month on sale, and passed the two million mark during its first four months. Those are impressive numbers for any game, let alone one that spawned from a user-generated mod and is still in the alpha stage of development.
But DayZ (and its me-too competitors, The War Z and Rust) is one of the only places for gamers to fend for themselves in a lawless, digital world. Players are tossed into an abandoned wilderness with few supplies and are left to their devices to find a way to survive through unpredictable encounters with other desperate survivors. Sure, it's rough around the edges, but that clearly hasn't stopped gamers from ponying up nearly $30 to buy the unfinished game. No one knows if the title will ever be completed, but the developers are aiming for a beta release in the fourth quarter of this year.