Speaking to us in an interview earlier this month, Valve MD Gabe Newell described an action fantasy RPG Valve were once making - about fairies. The next issue of PC Gamer in the UK is a Valve spectacular, and part of that is a huge interview feature on why the company keeps making such surprising decisions. I sat down with Gabe, project manager Erik Johnson and director of marketing Doug Lombardi and asked: "Are there things you think you've failed at?" Their response was long, and that's how they got onto the fairy game.

Doug Lombardi: There were a few failed starts to build Left 4 Dead.

Gabe Newell: Well, there was the flying fairy game. Is that the one you were referring to?

Erik Johnson: That was just a different game that, when we stabbed it... (everyone laughs)

Doug Lombardi: ... It turned into Left 4 Dead!

Erik says it was a weird prototype game that had spells "based on movement and mouse gestures. It was so bad."

"That was a useful failure to us," says Gabe, "because it was so clearly dumb that it made us say, 'OK, what are we actually good at that we can do instead?'"

It's as hard to imagine Valve doing an action fantasy game about flying fairies as it is to imagine them making a truly bad one. Gabe is merciless about it, though.

"It was so bad," he says, "you wanted to ask yourself: 'How could we make a game that was this bad? And how should we make a game?' And we said we should focus on what we do really well, so why are we doing this game which was kind of a... it wasn't really an RPG... it was this action fantasy sort of role playing game that had no story. And then we said 'OK, that's so horribly wrong. What we should focus in on is AI and playing in co-op, and that's the interesting opportunity.' That was where Left 4 Dead came from."

There's more on what they feel they've failed at in the feature, plus a lot of more positive stuff about the crazy, mad scientist experiments they're doing to make the future of games better. Subscribers should be receiving their copies in the next few days, and you'll be able to buy it online and in shops from September 1st.