I came to Seattle for a two-week reporting assignment with little idea of what exactly I should cover. Sure, there are the obvious players: Microsoft, Amazon, Cheezburger, and Valve. But rather than focus solely on the history of Microsoft and Amazon, there’s also a pressing need to define the startup experience in Seattle. What makes Seattle’s tech scene tick? What about this city doesn’t receive enough press coverage? What is Seattle’s id?

These are complicated questions and can’t be answered in a single post. But I have to start somewhere, and so it might as well be in the one area that the city has managed to make a distinct impression: casual gaming.

Microsoft’s Xbox division is headquartered here, as is Nintendo’s North American headquarters. Then there’s Valve, PopCap, BigDoor, Wild Tangent, Z2Live, Camouflaj, and many more.

So many successful gaming ventures from such a small area. Why? Seattle does many things right, like mobile infrastructure and ecommerce, but those are natural extensions of carriers that were once based in Seattle, and Amazon and Microsoft’s strengths. Those are expected strengths for Seattle to have. But where did gaming come from?

I’ve spoken to a bunch of people and they all have their opinions. For instance, Keith Smith of BigDoor, a gamification startup which deals with numerous Seattle companies, who suggests that when people grow up here, they tend to stick around and work for, as well as start, Seattle-based companies. That means they share a common Seattle experience in common: rain.

The theory goes that, because it rains so much, people are forced to stay indoors. And as they grow older, they run out of games to play and so create their own games, mostly on computers.

The rain could well be a contributing factor, but that seems too simple an explanation.

The answer might also partly lie in the region’s history. Nintendo of America, Nintendo’s regional subsidiary, is based in Redmond. The company brought its headquarters here in the 1980s and was one of the larger technology companies in the area. Throughout the 80s and 90s, Nintendo’s popularity took off with a large part of its growing market in North America.

This led to an influx of engineers and computer scientists to Nintendo’s regional headquarters, which gave the city a concrete foundation on which to build a gaming ecosystem.

And so, in the mid-to-late-90s and early 00s, a number of gaming companies arrived on the scene. Companies like Valve came out of the existing and dominant companies, such as Microsoft. As Todd Hooper of Zipline put it, “People don’t realize Valve, and how big they are, is the gaming equivalent of the App Store. Content, game technology, and a distribution platform. It is in an unassailable position.”

These companies then began to form the next generation of gaming centers, which further solidified Seattle as a gaming hub. Later came companies like PopCap, along with the current crop of startups that are just getting going in the last few years.

This is similar to Silicon Valley’s history, in which one successful group of companies begets followers. But what lies ahead? With Silicon Valley, few could have imagined that Fairchild Semiconductor would lead to Intel and the “Fairchildren Mafia” that surrounded it, or that PayPal would then lead to nearly every major company in the Bay Area today via the PayPal mafia. Looking back it’s obvious, but at the time not so much.

Right now, Seattle’s gaming ecosystem seems to be at a similar point. While bigger companies are doubling down on investments, other hopefuls are starting up, and the offshoots from the 90s and early 00s are as strong as ever.

I’ll be here for the next week, digging deeper into these questions, trying to figure out where the gaming industry is headed, and seeing how the city of Seattle serves as a driving force for it all.