Brandon Sanderson’s Mistborn TTRPG Lays the Groundwork for His Next Series

Published Nov 4, 2026, 2:01 PM EST Sam covers TV, movies, games and books at Polygon, making recommendations about what to watch and play while interviewing actors, writers, and designers about their work. She has spent 15 years working as a journalist and critic, with bylines across numerous publications including IGN, GamesRadar+, The A.V. Club, The Verge, and Windows Central. Brotherwise is preparing to take the Cosmere into the Space Age Image: Brotherwise Games Last year, Brotherwise Games published a set of three tabletop role-playing game books set in the world of Brandon Sanderson’s epic fantasy series The Stormlight Archive. The company quickly followed up the project by announcing an expansion to the Cosmere RPG based on Sanderson’s Mistborn setting, and the new books reveal the true scope of the company’s ambitions. The Mistborn Handbook, Mistborn World Guide, and Mistborn Legacy campaign are spread across two eras representing the two series Sanderson has written set on the planet Scadrial. It’s also laying the groundwork for Sanderson’s next trilogy in the setting. “There was actually a moment about a third of the way into development where we might have had to just do Era One,” Meric Moir, co-lead designer of the Mistborn World Guide, told Polygon in a virtual interview. “Brandon Sanderson was really starting work on his Era Three novels, and as he got a clearer picture of what he was planning, he was very concerned about anybody adding to Era Two, and wanted to be very clear that we shouldn’t box him in.” The Brotherwise team worked closely with Sanderson and Dragonsteel Books to expand some content for Era Two — which is set in a period akin to the Gilded Age — without interfering with the upcoming series, which will push the world’s timeline into the equivalent of the 1980s. They were able to add to the lore of how the godlike being Autonomy first became aware of Scadrial and established a secret organization called the Set. Image: Brotherwise Games “They started to give us a little bit more freedom to develop and pitch things that Brandon would review and say, ‘Yeah, actually, you know what? I didn't think of that. Let's go that way,’ or ‘I don't have a plan there. Why don't you come up with something, and then I can tell you if that'll work or not?'” Moir said. Brotherwise co-owner and creative director Johnny O'Neal held weekly meetings with Dragonsteel to go over every piece of art in the books to ensure all the details were canonical and consistent. That’s especially important given the Mistborn World Guide is providing a first look at characters who will appear in AppleTV’s upcoming adaptation of Mistborn. “I don't know what Dragonsteel is going to do, or what Apple is going to do, and I doubt they'll be constrained by us, but I can always hope that some of the things that Brandon has canonized with us will translate into a live-action thing, particularly the ethnicity of people in the Final Empire, like Dockson, who we got to canonize as Black, or Shan Elariel, who looks mixed race,” Moir said. Image: Brotherwise Games The Mistborn TTRPG books offer an enormous number of options for characters who can use 16 different metals for 32 powers, far more than the 10 types of surgebinding found in the Stormlight TTRPG books. “Because they’re not developed for a game, some of them have far more depth than others, and some of them are just useless on purpose,” Moir said. “It became obvious early on that not every metal was going to have equal weight of mechanics.” Gold allomancers can see possible versions of themselves, a power represented by just two talents. For comparison, using Iron to pull other metal objects is represented with a seven-talent tree. “Brandon and his team have said ‘Sorry Brotherwise, the fans don’t know all the things that you could do with gold. There will be more, but we can’t reveal that,'” Moir said. “We can talk about what we know, and right now that’s small. One of the cool things about our system is we can just add on trees if we need to later as more information is revealed.” The Mistborn TTRPG is bridging multiple worlds Image: Brotherwise Games The Mistborn rules also tease how worldhopping games could work if gaming groups want to explore the full breadth of the Cosmere. Burning Aluminum seems useless on Scadrial, but the art shows someone using it to negate the powers of a surgebinder from Roshar. Moir said the playtesting didn’t just focus on how the Mistborn abilities were balanced against each other, but how they would interface with the Stormlight books and other projects incorporating magic from Warbreaker and Elantris. “Worldhopping is something that any Cosmere fan brings up in the first or second sentence when talking about the games,” Moir said. “Supporting that in a more robust way going forward is definitely on our radar.” Moir is also the RPG director for Plotweaver, Brotherwise’s underlying rules system, and he’s been designing those rules with an eye towards what can be applied to the Cosmere. “One very good example is vehicle rules,” Moir said. “We’re doing a science fiction setting so we’ve got spaceships, but the core of those rules will be modular. We can pull them back to Cosmere when Cosmere gets to its Space Age and we can customize it to be what Brandon Sanderson needs for telling an Isles of the Emberdark story.” The Mistborn TTRPG is available today. Brotherwise will announce its next Cosmere project at the Dragonsteel Nexus in December.