Brandon Sanderson Says ‘Mistborn’ Script Is 10% Done

Brandon Sanderson has delivered the kind of update Cosmere fans have been waiting years to hear. The author revealed he is now 10% finished with the Mistborn screenplay, calling it “very good progress.” For a project with a famously long and winding road to the screen, that number feels significant.

The update comes just weeks after Apple TV locked down the rights to Sanderson’s Cosmere universe, with Mistborn set up as a series of feature films. Sanderson is writing the initial draft himself, giving fans rare reassurance that the adaptation is in the hands of its original creator.

From 2% to 10% in Two Weeks

Sanderson shared the milestone in a recent YouTube update, explaining that a minor shoulder surgery caused him to miss a previous livestream—but hasn’t slowed his writing. Two weeks earlier, he had reported the screenplay sitting at just 2%. The jump to 10% suggests he’s moving at speed.

As always, he’s tracking progress publicly on his website, where readers can follow percentage bars for each ongoing project, including the Mistborn script. That transparency has become a hallmark of his process and a comfort to fans juggling excitement for adaptations with anticipation for upcoming Cosmere novels.

Sanderson also addressed why he canceled a planned livestream shortly after the Apple announcement. With industry labor tensions making headlines, he opted not to discuss Hollywood work at that moment. While he isn’t currently a member of the Writers Guild of America, he made clear he would not continue writing the screenplay during a strike out of solidarity.

A Long Road to the Big Screen

The journey to adapt Mistborn has been anything but straightforward. Film rights have changed hands multiple times over the past decade, including a high-profile deal with DMG Entertainment before the project stalled. At one point, Sanderson described the adaptation as effectively back to square one after development efforts failed to secure a production deal.

The new Apple arrangement appears different. Industry coverage has highlighted the “unprecedented control” Sanderson now holds under the Cosmere deal, a shift that could prove crucial for a world as intricate as Scadrial and its allomantic magic system.

For readers who first stepped into Luthadel with The Final Empire in 2006, this 10% milestone is small but meaningful. The screenplay is still in its early chapters, and no casting or production timeline has been announced. But for the first time in years, Mistborn isn’t just optioned or in development. It’s actively being written.

And in the world of fantasy adaptations, that’s real progress.