How horror thriller 'Fall' used tech to cover up more than 30 F-bombs to score a PG-13 rating

When you’re stranded atop a 2,000 foot-tall radio tower, no one’s gonna hold it against you if you drop a fear-induced curse word or two. But when you’re doing it in a small-budget thriller film trying to broaden its audience appeal with a PG-13 rating, it’s probably a good idea to keep your panicked potty mouth in check.

Lionsgate’s sky-high thriller Fall was reportedly facing just such a conundrum after already filming its scenes in California’s Mojave desert — and on a budget of only about $3 million, according to Variety. In the process, the cast — which includes stars Grace Caroline Currey (Shazam!), Virginia Gardner (Marvel’s Runaways), Mason Gooding (Scream), and Jeffrey Dean Morgan (The Walking Dead) — reportedly managed to rack up more than 30 on-screen F-bombs and other PG-13 word obstacles. The movie’s lean budget, of course, meant reshooting all those speaking scenes wasn’t an option.

That’s where Fall director Scott Mann’s technology company came in. Deploying a proprietary artificial intelligence engine that operates similarly to video deepfakes, Mann reportedly tapped the computer-driven brain power of London-based Flawless (where he serves as co-CEO) to sterilize the movie’s many curse words — while also manipulating the actors’ mouths on film to make it appear that they were actually saying their new dialogue touch-up lines (like “freaking” instead of “f***ing”).

The swear-word sanitizing effort isn’t all that different than what Flawless’ AI engine — called “TrueSync” — was intended to do in the first place. The technology “alters the mouth movements of the actors to match the alternate dialogue being spoken (a process the startup calls ‘vubbing’),” Variety’s report states, though the tech originally was developed to make dubbed translations of imported films more believable...not to tidy up an R-rated tirade of expletives.

Still, the process is more or less the same, and it reportedly worked so well to rein Fall’s dialogue back into PG-13 territory that not even the cast could tell where the AI had done its scrubbing work. “As far as I know, every movement my mouth made in that movie, my mouth made,” said Currey, who along with Gardner stars as one of the two lead characters who make the film’s dangerous radio tower climb.

Viewers will have to spike Fall’s vertigo-inducing scares with their own R-rated swearing if they’re duly inspired by the movie’s heart-racing heights, but they won’t have to wait long to see if anyone can beat the actors at spotting all the AI-powered dialogue swaps. Fall is poised to rappel into theaters (with its PG-13 rating fully intact, of course) beginning Friday, Aug. 12.

Looking for more thrills at the box office? Beast, starring Idris Elba as he takes on a rouge mountain lion stalking his family, opens August 19 in theaters.