The Hilarious Accident That Happened On The Set Of Scream

From the pea-green projectile vomit in "The Exorcist" to the chest-bursting jump scare in "Alien," some of the best on-screen scares weren't even intentional — with film crews occasionally keeping actors in the dark about details to capture their genuine reactions.

Not all improvised moments in horror are terrifying, though. Wes Craven's 1996 slasher film "Scream" reinvented the genre with its meta-commentary and ironic humor, partly due to improvised lines by the cast. On the r/MovieDetails subreddit, one user shared a piece of trivia from the film's commentary track featuring Craven and writer Kevin Williamson. The duo shared surprising facts, like how it was decided at the last minute that one character would survive in case audiences wanted him in a sequel. They also shared that many lines were made up on the spot, and one hilarious moment — the result of an on-set accident — stood out to fans in the Reddit thread.

After it's revealed that Billy Loomis (Skeet Ulrich) and Stu Macher (Matthew Lillard) are the Ghostface killers targeting Sidney Prescott (Neve Campbell), chaos ensues. Billy and Stu tell Sidney about their scary-movie-inspired revenge plan to frame her father for the killings, which included carefully wounding each other to look as though they had barely survived an attack from the "real" Ghostface.

However, as tensions run high and their plan begins to fall apart, Stu winds up slumped over the counter, spitting up blood, while Sidney taunts him and Billy on the phone. Billy becomes increasingly manic and whips the phone down, smacking his dying friend in neck in the process. Stu responds with an iconic, expletive-laced wail that was totally unplanned.

In the "Scream" commentary track, Wes Craven said that the phone wasn't supposed to hit Stu. Skeet Ulrich's hand was covered in slippery fake blood, so his aim was off, but Matthew Lillard didn't break character and quickly delivered a funny line. Kevin Williamson added that Stu was an underwritten character, but Lillard's charisma and wit allowed for plenty of amusing improvised moments.