Last year, Macklemore became the first Seattle artist to sell out three consecutive nights at KeyArena. Bellevue video gaming studio Valve topped that feat—in four minutes. This July the four-day world championship of Valve’s free online multiplayer game Dota 2—dubbed the International—takes over KeyArena. Dota 2 pits teams of five players in fantasy battles that mix chesslike strategy with the relentless, hard-hitting action of football. How big is Dota 2? More than a million people watched last year’s finals online, and this year’s prize pool tops $6 million. The game’s director, Erik Johnson, helped us make sense of the phenomenon

How does a video game work as a spectator sport?

It’s actually really fun to see somebody do something that you really enjoy doing, but doing it a lot better than you. It’d be like if there was a Seahawks game where everyone in the entire audience was an amateur football player.

It’s an Internet community, which is different than a fan base. Fans come to one spot and all cheer for the team, but a community has a clear understanding that they’re all generating value for each other in different ways, whether it’s by commenting on a message board or playing together or making each other laugh.

Do you play Dota 2?

We play every day. But I don’t think we’ll be competing in any international tournaments.

Were you expecting to sell out so quickly?

Our expectation was that we would sell it out. We’d run the event at Benaroya Hall, and I believe we sold 1,800 tickets to that. Those went really quickly, so we expected to sell out Key with the size of the audience, but no one predicted that we would sell out so quickly. So that was a surprise.

Since it’s sold out, how can people watch?

It’s streamed live on Twitch TV. It’s a production that’s on the level of the Masters or any really big sporting event. It’s very entertaining, just in terms of pure sport for people that are outside the community.

I’m guessing the International is a little more frenetic than the Masters.

Yeah…