The Expanse, the wildly popular series of science fiction books that became a beloved Syfy television show, was at one point a homebrew tabletop role-playing campaign. Now, with the help of Green Ronin Publishing, it’s going legit.

Polygon sat down with Ty Franck and Daniel Abraham, who write under the pen name S. A. Corey together, to discuss the lost history of their Hugo-nominated series and their ongoing Kickstarter campaign for The Expanse Roleplaying Game.

The Expanse book series, which began with 2011’s Leviathan Wakes, focuses on a humanity’s plight several hundred years in the future. In that universe, the citizens of Earth are allied together under the United Nations against the citizens of Mars. Caught in the middle are the Belters, humans who, for generations, have grown up in industrial centers far from the central planets with little-to-no gravity. It’s a story of political intrigue, but also a classic spacefaring adventure. No wonder it spawned a popular television series, whose fourth season was recently picked up by Amazon Prime.

But, in an alternate universe, The Expanse never became a TV show. It didn’t even become a book. Instead, it was turned into a niche massively multiplayer online game in China.

“The Expanse started out as a pitch for an MMO,” Ty Franck told Polygon. “It was right before Eve Online came out [more than 15 years ago].”

“A friend of mine asked me to come up with a pitch that she was going to take to her uncle, who was associated with a Chinese company that wanted to make an MMO. That’s how I came up with what eventually turned into The Expanse. The Chinese company apparently didn’t realize that developing an MMO was a $100 million project, and once they did realize that, they sort of just backed away quietly. But they hadn’t paid us for anything. So I still owned everything I came up with, and I just kept playing around with it.”

From there, Franck adapted the pitch to the d20 Modern Roleplaying Game, a system published by Wizards of the Coast in 2002. He credits that game for inspiring the gritty, lived-in feel of his world.

“I just used d20 Modern,” Franck said, “and then kind of added my own futuristic stuff. Which is why The Expanse feels very grounded in today. It’s because the rule system was very ‘today,’ so no laser guns, no plasma weapons.”

Around the same time, Franck moved to Albuquerque, New Mexico. That’s where he met Daniel Abraham, who soon became one of the players around his table. In fact, it was Abraham’s own d20-based character who would go on to become Joe Miller, the fedora-clad Star Helix Security detective played by Thomas Jane.

“In our game, the crew of the Rocinante had 12 people in it,” said Franck, referring to the stolen Martian Navy ship that Leviathan Wakes’ protagonists make off with early in the novel. “We borrowed a couple characters from our d20 game, with the permission of the players. But they’re quite radically different than what they were, in some cases very radically different than they were in the game. We just borrowed a few different personality elements.”

Those characters include Amos Burton, Alex Kamal, Naomi Nagata, Shed Garvey and James Holden.

“I always liked Holden because he was the least like me human that I could possibly write about,” Franck said. “We’re nothing alike.”

Now the team at Green Ronin Publishing is trying to bring the history of The Expanse full circle. Its Kickstarter campaign for The Expanse Roleplaying Game is already successful, having raised more than $270,000 on a modest $30,000 ask.

“It helps that they are gamers,” said Chris Pramas, founder and president of Green Ronin Publishing. “It’s good to be able to work with people who fundamentally understand the product that we’re making and the sorts of games that we make.”

Fans of The Expanse show can expect the final product to focus heavily on the survival aspects of space travel, including the need for oxygen and food, but also plenty of action. The Expanse Roleplaying Game will include rules for fighting on foot in powered Martian combat armor or from the cockpit of your own spaceship.

Fans of the novels, on the other hand, can look forward to a level of fidelity simply not possible in the TV show.

“There are physical limitations that the TV show has to operate under,” Franck said. “It’s hard to find a seven-foot tall woman to play Naomi. They do not exist. But for these guys, when they do art for Naomi, she’s almost seven-feet tall, and she’s very thin, like a Belter should be. Amos can be the hulking, 350-pound guy that he is in the books. [...] Their art will be a version that, in some ways, is closer to the books than the show.”

Delivery of the finished product is expected in November 2018. The Kickstarter campaign runs through Aug. 22 and includes a leather-bound version at some tiers. Green Ronin said that it will make the final product available in both a physical and a digital format. You can download the quick-start version right now.