Brandon Sanderson on Infinity Blade’s infinite story

September 3, 2013, 1:08 PM UTC

FORTUNE — Brandon Sanderson grew up playing video games on Nintendo (NTDOY) consoles, a hobby he never gave up. Now the New York Times bestselling author (2009’s The Gathering Storm and 2010’s Towers of Midnight) is actually helping to craft video game stories. Sanderson, who is writing multiple science fiction projects and has seen two of his books optioned by Hollywood (Mistborn by Paloppa Pictures and Alcatraz Versus the Evil Librarians by DreamWorks Animation), has been collaborating over the past three years with Chair Entertainment on the iOS game, Infinity Blade.

The first two mobile games in this action franchise, which blends elements of fantasy with science fiction, have sold over 11 million copies worldwide and generated more than $60 million in revenue. This feat is especially noteworthy given that Chair Entertainment charges $6 for the game at a time when many mobile offerings are free-to-play. Donald Mustard, a co-founder of Chair Entertainment, reached out to Sanderson early on through a mutual friend to ask the author if he’d like to collaborate on this franchise.

“We got together and brainstormed, and the idea was that I would write a book that would be a sequel to the first Infinity Blade game,” said Sanderson, who lives in Salt Lake City not far from the game studio. “It was exciting because the Infinity Blade game had all these hooks for a story, but the game itself did not have much of a story. That gave me a lot of freedom to explore the world more deeply and actually make a cohesive setting out of it.”

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The result was the bestselling eBook, Infinity Blade: Awakening, which debuted at No. 1 on iBooks. The title has remained on the fantasy top-seller charts since releasing on Oct. 4, 2011. That book gave fans a rich transmedia experience while Chair was at work on Infinity Blade II. Sanderson said his book took the game’s story in much different directions than the development team had originally envisioned, which allowed the game makers to explore more than just the addictive swiped-based tablet and mobile gameplay experience.

“The characters that I added in the book became main characters for the game, and Chair extrapolated that and took things in a direction and tossed story back to me for the second book,” said Sanderson, who likened this cross-media creative experience to juggling chainsaws. “At the end of Infinity Blade II they left the characters in this terrible situation, and I had to deal with that. We brainstorm on all of this stuff, and we work together, but it’s been a blast to see how what I do for a book influences what they do for a game and then to be influenced by that to make the next book.”

The second eBook, Infinity Blade: Redemption, which has received strong pre-orders, was released this Tuesday and has already hit the top spot on iBooks’ fantasy chart and is No. 2 of all iBooks. This type of collaboration is unique in the growing mobile games business. While the traditional model of having a book turned into a movie and then a console game remains the norm (Sanderson’s own Mistborn book is being developed as a game), this type of collaboration between a bestselling author and a mobile game studio is unique. Mustard said the proliferation of tablets and mobile devices has opened up the opportunity for fans to explore worlds in different ways on the same screen.

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“We wanted to make the Infinity Blade franchise more than ‘just’ an interactive experience,” said Mustard. “You can literally be playing Infinity Blade I and be experiencing the universe and the story, shut the game application, open the digital book that’s written by Brandon Sanderson, start reading about the universe, and continue the story on the same device, but in a totally different medium. Then you finish the book, start playing Infinity Blade II, and the story continues. Then you can read the second book. It’s a way that we can start to have these more unified media experiences on one central device or multiple screens, but that it expands the story and the universe all still in the palm of your hand.”

The Infinity Blade franchise, which is built on Epic Games’ Unreal Engine 3 technology, is also blurring the line between mobile and console gaming, as well. The second game even spawned a stand-up, swipe-based arcade machine that can be found at Dave & Buster’s and other locations around the country. The game’s vibrant visuals, when played on an HD TV, look on par with current generation console offerings.

Gamers have loved this universe. To date, the Infinity Blade games remain among the two bestselling games in the mobile space. Over 40 million players around the globe have played the game.

“This year mobile gamers have spent approximately $6 million dollars on Infinity Blade II across the globe,” said Peter Warman, founder of video game research firm Newzoo. “Forty percent of that comes from the U.S. Japan is their second biggest market. It has been a long time since the original Infinity Blade topped any chart. But looking at the paid games market, it’s still is one of the best performing games of all time.”

On average, Infinity Blade game-play sessions are three times longer than the average game-play session on iTunes. Chair has been able to utilize an in-game store to seamlessly drive fans from game to books to soundtrack. In the near future, Chair will add new products like toys and comics to the universe.

“One of the reasons I agreed to doing this in the first place was because I’m excited by this prospect of new media,” said Sanderson, who has a traditional hardcover book, Steelheart, shipping on September 23. This past weekend, Sanderson won two Hugo Awards for some of his other projects. The honors focus on the best works of science fiction as voted on by members of the World Science Fiction Society.

“It seems like everything is pushing this direction. Your Xbox is no longer just a video game console, it plays movies and even original TV shows like the upcoming Halo series. Your iPad is no longer just this device that you read books, play games, and web browse on. It can hook to your TV and control your house. Everything is blending together with this new generation of technology. “It allows us as storytellers to tell stories in a brand new and unprecedented way.” Mustard and Sanderson believe there are still more stories to tell in this universe.