PlayerUnknown's Battlegrounds is the game of 2017. Debuting in late March after a smart marketing campaign put its closed beta in the hands of big YouTube and Twitch personalities, it was an immediate hit, shifting two million copies in a fortnight. Somehow, things snowballed to an insane degree from there. More than 20 million copies of the battle royale title have been sold, and with a peak concurrent player count that regularly tops two million, it is the most-played game on Steam. More than 15 million people played it in the past week. Oh, and it's still in Early Access. What.

Brendan Greene, the game's 41-year-old creative director and designer, is as surprised as anyone by the scale of PUBG's success. "We're still trying to figure that out," he says, before offering that the game's emphasis on player freedom, "pretty good" weapon mechanics, and simple concept are a large part of its appeal. "It's a bit surreal," he adds. "We had an expectation of five million in the first year. We're not letting it get to our heads… All hands on deck to get 1.0 out the door."

Battle Royale: PUBG's Brendan Greene on life in the spotlight

The "we" in that paragraph is Greene's employer, PUBG Corp., a subsidiary of South Korean developer Bluehole, which made MMORPG TERA. According to a report by Bloomberg, the studio's value has reportedly increased five-fold in just three months, to more than US$4.6 billion.

Greene's role in this meteoric rise, and his personal rags-to-riches tale, are well-documented. A photographer and graphic designer, he married a Brazilian woman and moved there in his early 30s, only for the pair to divorce and Greene to be stranded. While working small photography gigs, he became interested in modding, and found a sizeable audience with mods for Arma 2 and DayZ based on the 1999 Japanese novel and 2000 film Battle Royale.

"We had an expectation of five million in the first year. We're not letting it get to our heads"
Brendan "playerunknown" Green, creative director
Battle Royale: PUBG's Brendan Greene on life in the spotlight
Battle Royale: PUBG's Brendan Greene on life in the spotlight

Greene eventually moved back to Ireland, and then in late 2014, Sony licensed his battle royale concept for H1Z1. That saw Greene consulting at Daybreak, before the fateful day when Bluehole got it touch. Executive producer Kim Chang-han reached out to Greene via email, and the pair discussed what they believed the ideal battle royale game would look like. There was pretty much across-the-board agreement.

"It synced up a lot with what I wanted to do myself," says Greene, so he shot across to Korea and checked out the concepts Bluehole had put together. "The level of detail they put into it really impressed me. That's when I decided I'd work with them." That put him in the role of creative director for the first time. "Luckily I had a great team that supported me on that."

When he's not globetrotting to conventions like PAX and conducting wall-to-wall interviews all day, a typical day for Greene is working 12-14 hours beginning at 10am. He keeps in eye on what each team is up to, but each can manage itself at this stage thanks to the flat structure in place at PUBG Corp. "The vision is there, they all know what Battlegrounds is meant to be," Greene says. He spends weekends sleeping. It amounts to something of a gruelling schedule, but one he knows is only temporary.

That said, the studio has a five year plan for the game. "All we wanna do is provide this as a global service," Greene says. "New maps, assets, continually refine, and improve. Make custom servers better." Right now, it probably feels more like constantly putting out fires. For example, the recent addition of China multiplied the number of hackers in the game, and resulted in a tsunami of negative Steam reviews. Bluehole is still building anti-cheat systems, and is considering working with third-parties as well, but the influx frustrated many in the community.

Battle Royale: PUBG's Brendan Greene on life in the spotlight

"Yes we are seeing a wave," Greene says. "This is a top priority for us, making the game competitive for everybody. With the explosion of popularity in China there is going to be a lot more hacks released. These guys are very smart. The hacks we're seeing are malware level hacks where they are coming in through the Windows terminal, it's crazy the work they are putting in just to hack a game."

The hacks we're seeing are malware level hacks where they are coming in through the Windows terminal, it's crazy
Brendan "playerunknown" Green, creative director

In fact, the rate at which the game has grown has become something of a liability. "Our leaderboard system wasn't meant to handle the number of people we see at the moment, so there is certain things we can't do like remove cheaters that have already been banned," says Greene. Scaling up hasn't been a matter of adding zeros to functions and activating extra servers.

There's also the community, which is as insatiable as it is passionate. Patience for bug fixes and new features isn't abundant in some corners of the game's massive playerbase, and there's constant cries for improvement. Many don't understand that some problems don't disappear any faster just because you throw manpower and money at them. Even so, Greene is grateful to be in the position he is. "We have a great community," he says, "they just want to see great battle royale games. We're lucky to have them."

Another aspect of the game recently under scrutiny is its 17 Hz "tick rate" average, which has been compared unfavourably to that of CS:GO and Battlefield – a comparison Greene doesn't believe should be made. "Because we're a massive open world game with 100 people on it, it's different to other competitive games people might see," he says. "So you can't really compare our tick rate to CS:GO or smaller games with fewer players."

Even so, Bluehole is pledging to improve the figure. "It's something that we plan to work on for years to keep improving it," Greene promises. "These things take time, they take months to complete. Rewriting complete systems. For example, we can't do updates now until we hit 1.0 because of the fact that we just upgraded our engine internally and that's broken a lot of stuff, and we can't update the live servers with a broken build."

As for the game's Xbox One version – which launches into Game Preview on December 12 – Greene says it's pretty much the same game except the view distance is shorter. As you'd expect, the team has worked hard to get the game feeling nice and smooth with a controller. "The first build I'm pretty happy with," Greene says, adding that crossplay is a possibility. "We'd love to see it, but we have to figure out the best and fairest way to do it… we want to see the whole community playing together."

That community is big enough to include some pretty high-profile celebrities. "I'd love to meet Terry Crews," Greene enthuses. "He plays the game and is a big fan. And it's Terry Crews! Who doesn't wanna meet him?" But despite his new proximity to glitz and glamour, Greene doesn't see himself being changed by his upward trajectory. "I'm a cynical fucker anyway, so I think I'm a pretty good judge of character. I'm not worried at all. I tend not to flaunt my success."

PlayerUnknown’s Battlegrounds is coming to Xbox One through the Xbox Game Preview program on December 12. The full PC version is scheduled to launch in late December.