Portal is my favorite videogame, it came out just about a year ago. For the uninitiated, the game is built around a new gameplay mechanic: portals. In a twist on the standard First Person Shooter (FPS), instead of having a bang-bang gun, you have a portal gun. It shoots two things, a blue portal and an orange portal. The portals form on any flat surface and anything that goes in one instantly comes out the other. Here’s the trailer:

Valve, the company who developed Portal, has a long history of openness with their games. With their first game, Half-Life, Valve released a Software Development Kit (SDK) that allowed amateur game designers to build their own games on top of the existing engine. Counter-Strike, arguably the most popular FPS game ever, was the result of a fan-made project built on top of the Half-Life engine. Valve ended up hiring the team behind Counter-Strike, and eventually made a sequel.

Staying true to form, Valve released an SDK for Portal. So far as I knew, it was mostly used to make new levels with new challenges. Monday, it was announced that for the past eight months, a fan-made prequel, Portal Prelude, has been silently under development. It serves not only to add content to the existing game, but also greatly expand the scope of the story. In fact, Valve has even approached the team to offer their support and congratulations.

The team released a trailer for their project:

It’s tremendously professional.

Valve has done a fantastic job of building a loyal community around their games, and they’re very relaxed about amateur teams using their characters and settings to tell new stories, it’s very reminiscent of the Japanese manga culture. But instead of just providing their fans with material to adapt, Valve also gives them first-rate tool to work with. Based on the Portal: Prelude trailer, those tools look to be usable to great effect.

Valve, and other companies that open their games, are providing their consumers, and potential employees, with far more than a game, they’re selling a platform (and access to a loyal and enthusiastic community). It’s a fantastic example of openness and prosumption, and with benefits shared among everyone involved. This fan made extension of the story is fitting, given that the original development team was a bunch of students who caught the eye of Valve at a trade show, they were brought on board. Maybe the same thing will happen to this team…

Prelude is due out this month, here’s to hoping that my excitement isn’t misplaced!