The Last of Us, by Naughty Dog, will launch on May 7. We speak to director Neil Druckmann about the game's ideas and production.

Undying, near impervious to harm; rampant hordes of the things too numerous to count. Like their decomposing lead monsters, zombie games are an almost unstoppable force, which only swells in numbers as time goes by. Even before they shuffled into the limelight with 1996's Resident Evil, zombies were familiar videogame fodder.

Palace Software's 1984 adaptation of the Evil Dead featured them heavily, and later, games like Corpse Killer would also see players fighting the undead. Resident Evil changed the landscape by adding puzzles, limited ammunition and genuine scares to the mix, but since then, over the past 17 years almost, zombie games have gone rotten. What's needed is some new blood.

The Last of Us by Naughty Dog could be exactly that. A pioneering force behind the horror game's new wave, it's set to foreground characters over bloody thrills, and pose searching questions about who you're playing and what you do.

Rash decisions

It's 20 years from now, and the world is overrun by 'Clickers', ex-humans that have been infected with spores from a tropical fungus. You play Joel, a middle-aged, hardcore survivor who's tasked with escorting a young woman called Ellie to the other side of the US.

Cities and towns are being steadily reclaimed by nature, and aside from the Clickers and the wildlife, the only things left alive in America are its savage former citizens, who would sooner beat you to death for the can of beans in your rucksack than be your friend.

Forced to make increasingly rash decisions as Joel, your violent behaviour brings out something murky in Ellie; creative director Neil Druckmann wanted the dynamic between the two characters to be at the centre of the game:

"We wanted to approach this genre from a character driven standpoint. So, we needed to find a pair of characters - which ended up being Joel and Ellie - who need each other, whether that's for survival or for an emotional hole that they each have.

"The goal was to spend the entire game building their relationship. When they first meet they don't know each other, they don't even like each other very much. So, we wanted to ensure that the actions you do in the game mirrored their emotional journey, their ups and downs.

"Joel is a guy who's lived on both sides of the apocalypse," Druckmann continues. "He knows the world that we know, but he's also used to surviving in this dark, other world. From doing increasingly worse and worse things to stay alive he's become very cynical.

"Ellie has only known the apocalyptic world. The horrific things are day-to-day to her. And yet, certain things that Joel does still shock her. There's a sense of, although he's doing what he needs to do to save her, Ellie goes down with him. We have this interesting dynamic between the two characters."

Cut Scenes

Ellie and Joel's relationship doesn't just exist in cut scenes and dialogue; the specks of gameplay footage that are available now show players helping Ellie onto ledges and sharing out supplies. But that's mere Resident Evil 4 stuff. What's really impressive about The Last of Us is how Ellie helps out in combat.

Overwhelmed by hunters and out of ammo, Joel crouches behind cover with nowhere to go. Seconds before his would-be attacker is on him, Ellie pelts the guy with a brick, giving Joel an opening to counter attack. Moments like these happen, seemingly, at random, with Ellie chipping in organically whenever the situation arises. By throwing Joel spare bullets or distracting the bad guys, Ellie's relationship to the player grows closer; even if you aren't paying attention to the writing, you still feel dependent on your companion:

"The thing that inspired us the most was when we were making Uncharted 2," says Druckmann "and there's a sequence where Drake meets up with this Sherpa called Tenzin who doesn't speak English. And you build a relationship with him through gameplay - at the end of it you feel like you've built a bond with this guy even though you haven't understood anything he's said to you. It was so interesting to us. What if we built an entire game around this concept, of building a relationship through gameplay?

"We showed at E3 how Ellie jumps on a guy's back and saves Joel. So, even through gameplay you're led to feel like 'she saved my ass back there, I like having her around.' And then there are times when you're walking around and seeing these horrific things, and Ellie sees it in a different way. She says 'wow, this place is kind of pretty.' And it might make you realise that yeah, it kind of is. So, hopefully through narrative - through dialogue and through action - you start forming this bond."

And in the way that Joel's violent survival instincts - tragically - toughen Ellie up, her optimism brings something out in him:

"I wanted to slowly pull out the humanity in Joel," Druckmann continues. "At the beginning of the game you'll see the things he's capable of, but we wanted to say that even that kind of guy can care for someone else, can be vulnerable."

Joel and Ellie

Generally speaking, videogames and their players aren't concerned with performative quality - hairstyles and trademark weapons do more for videogame characters than soliloquies, and the industry is yet to have a healthy stable of actors. But in The Last of Us, Joel and Ellie's relationship is at the centre of everything. Without a strong performance from those two characters, the game would crumble.

Joel is played by Troy Baker, a veteran voice performer and bona fide leading man of the game world, whose upcoming credits include Booker DeWitt in BioShock Infinite. Ellie is voiced by The Killing star Ashley Johnson, an actress/musician from California who, according to Wikipedia, is an avid gun shooter.

Druckmann wanted his characters to have a plausible dynamic. He knew to cast Johnson on the spot but struggled to find his Joel:

"The first person we cast was Ashley Johnson as Ellie - that was one of those auditions where we just knew it on the spot. But we were having a hard time finding our Joel because we were looking for someone who you couldn't just describe as 'badass'; he's not your typical action hero. We wanted somebody who had a vulnerability to him that would contradict the hardened face he puts on to survive in this world.

"So, what we did was bring Ashley into all our Joel auditions to see what kind of chemistry she would have with the candidates. When Troy Baker walked in, the two hit it off straight away. They did this scene where Joel is meant to explode at Ellie, but [Troy] played it in a way you would explode at your mother, or brother, or someone close to you who knows exactly how to push your buttons. After that, it was easy to cast him as Joel."

Nuanced

Another, perhaps more nuanced result of Druckmann's dramatic process, the enemies in The Last of Us are disconcertingly human. Eavesdrop on a trio of hunters before the start of a big fight and the overheard dialogue is steps above the typical guard patter.

The hunters converse, they chat; they talk about what they've had to endure to get this far. And once they're engaged, they call out to one another and work in a team. Ambush one, and he'll scream "he's in here", grab another as a human shield, and the rest will yell at you to drop him, with genuine panic creeping into their voices. The guys you kill in The Last of Us are groups of friends. As Druckmann points out, you're no better than they are:

"We're going to make the violence as real as possible, so you buy into the scrounging, the scrambling - the desperation these people have. It was important to show that Joel is not necessarily a good guy. We don't glorify these kills. It's like he's just doing what they would do.

"In the games we worked on in the past, we'd do whatever we could to suggest that the bad guys were bad. You'd see them kill someone, or we'd design them will a skull on them, like in Jak and Daxter. Either through story or design we'd say that these guys are good and these guys are bad. Here, we took the opposite approach and thought about how we could humanise these guys, how we could show that these guys really cared for each other. So, when you do engage them, you feel like you're just like them but with a different objective. It's not just about spraying blood up the walls - you see it in the context of what it is.

"But then, like Ellie, over the journey you get desensitised to it. Players will go through these ups and downs where they'll be horrified by it, then get used to it and then be horrified by it again."

Monsters

There's a beating human heart at the centre of The Last of Us, be that in Joel and Ellie's strained relationship or the rapid pleas of your enemies. But although we're meant to be increasingly shaken by Joel's ability to be violent, there's a second, more immediate threat of him turning into a monster. Clickers, The Last of Us' nearest equivalent of zombies, pass on their killer fungus with a single bite. And although their exact role in the game's combat is yet to be fleshed out, Druckmann explains they're vital to The Last of Us' drama:

"[The game] started by being about human antagonism, the primal state we revert back to when we're forced to fend for our own. Then it became a question of what brought the world to this state, and it felt like because we're an action game we should represent the infection through action, so that, when you fight these things, you can imagine what happened to society during that twenty year period.

"The first variation had even crazier monsters, but they felt like things that were out there already. Then we grasped onto the themes that were unique about the project and steered in the other direction, where there were no creatures. But that left us with an action game where all we could do was talk about this thing instead of experiencing it. So, it was finding that fine ground between making sure it's fun but also that it's based on enough things you've heard of and can believe happened."

The Naughty Dog team would eventually find its inspiration in a Planet Earth documentary about cordyceps, a fungal spore which alters the behaviour of insects and can wipe out entire colonies of ants. In The Last of Us, its jumped to humans, turning people into animalistic psychos with disgusting growths on their faces.

"The thing we didn't want to do was some government conspiracy, where they were developing something and some terrorist group stole it," says Druckmann. "If we did, it would feel like the story would become about that rather than anything else.

"[Uncharted 2 director] Bruce Straley and me watched the documentary together and we thought 'that's awesome. Zombie ants. How come no-one's used that before?' And Attenborough finishes by saying that the more numerous a species becomes the more likely it is to fall victim to a cordycep fungus. Right away you think 'people.' That was the starting point for our world."

There's something...itchy about the Clickers. Freakish, shrieking, running things, the Clickers are a frightening hybrid of plausible reality and utter weirdness: Watching a cordyceps grow out the head of a bullet ant, even Attenborough notes it's "like something out of science-fiction."

Nevertheless, the centre of The Last of Us is Joel and Ellie. The Clickers might be terrifying, but they are not the story Naughty Dog wants to tell:

"You might encounter people who have theories about what happened, but we're never going to say 'this is the thing that happened'" explains Druckmann. "It's like with things that happen in the real world. No one really knows where bird flu or Spanish flu started. People have theories but they don't know.

"We're not going to reveal how this thing started. That's not what the story is about."

And nor should it be, because even now, with four months until launch, what's most impressive about The Last of Us are the details on Joel and Ellie's relationship - the look on his face when he cocks his gun, the tremor in her voice when he beats someone up - and to lose sight of those things would be to miss what makes this game important.

Coming together

Neil Druckmann has been working on The Last of Us for more than three years, and now, with the crunch about to start, when the whole team will be working 14 hour days, 7 days a week, he's relieved to say that everything is coming together:

"I recently played the game for the first time beginning to end, and I got to an area actually in gameplay where I teared up, because for that moment - not in a cutscene - it all came together. It's my hope that we can reach fans that way."

Horror games are beginning to change. The revolution spearheaded by The Walking Dead and Day Z has already shown that melodrama and pacing can have a much more lasting effect on people than exploding heads or electrified wheelchairs.

Not only the next stage in the zombie genre's reinvention, The Last of Us is set to refresh the third-person action shooter, placing characters, dialogue and performance at the game's nucleus as opposed to merely combat beats:

"I love games like this," concludes Druckmann "but they just feel like they're missing a character element. Joel and Ellie meet for the first time in the Boston quarantine zone, and their journey will take them cross-country over the course of a year. With each section, we're asking 'what is the state of their relationship, and what can we do with the art and gameplay to reflect that?' I think we can bring that character element."

The Last of Us launches exclusively on the PlayStation 3 on 7 May.