Avengers, to the (box office) rescue! “Avengers: Doomsday” has generated $16.5 million in advance ticket sales after the first day of availability.

Disney’s Marvel Studios put tickets on sale tied to the launch of the first trailer, which teased an epic battle as the Avengers and X-Men face off against the villainous Doctor Doom. Those pre-sales are impressive because tickets were only available for premium formats in just 1,000 domestic theaters. When “Avengers: Doomsday” opens the weekend of Dec. 18, the Marvel Cinematic Universe adventure will land on more than 4,000 North American screens. Showtimes for premium formats on Thursday, Dec. 17 and Friday, Dec. 18 are already largely sold out, according to studio insiders, and exhibitors are reportedly adding more screenings for Christmas Day and beyond.

First-day sales are also notable because they don’t include Imax, the most ubiquitous of the premium large formats. “Avengers: Doomsday” won’t have access to Imax because “Dune: Part III,” which debuts on the same day, has the entire Imax footprint exclusively for three weeks. (That’s because director Denis Villeneuve shot the third “Dune” with the company’s cameras.) Since premium large formats have been all the rage, especially with action-heavy adventures, Marvel introduced something called “Infinity Vision.” It’s not a new technology but rather a “certification” that guarantees movie theaters will “meet rigorous technical standards,” per Disney.