“I did show up one day with UGGs, and he looked down and went, ‘Nope!’”

During Monday’s episode (20 July) of CBS Mornings, Nolan explained to Gayle King that he wanted the cast to “stay in the moment,” and he felt UGG boots were a “signifier of modernity”. 

He went on to share that some of the cast would show up wearing the “big, fluffy, comfy” slippers – but they “weirdly take you out of reality”.

Anne Hathaway and Matt Damon know the rule all too well...

“I did show up one day with UGGs, and he looked down and went, ‘Nope!’” Hathaway previously told USA Today, before Damon laughed: “He hates UGGs more than anything.”

Under Old Hollywood’s strict Production Code, even married couples were kept apart on screen. Actors portraying husbands and wives were forbidden from sharing a bed – a rule that also applied to real-life spouses, including Lucille Ball and Desi Arnaz during I Love Lucy.

In a more wholesome on-set rule, Quentin Tarantino reportedly encouraged cast to say "hello" to longtime collaborator Sally Menke.

Menke, who passed away in 2010, edited every Tarantino-directed film from Reservoir Dogs (1992) through Inglourious Basterds (2009), becoming one of the director’s most trusted creative partners.

Stanley Kubrick was famously against improvisation on set – with one notable exception: Peter Sellers.

Kubrick’s longtime collaborator James B. Harris explained that while some improvisation happened during rehearsals, it was carefully shaped into the final script. 

He said: “During rehearsals, we did a lot of improvisation, but Stanley created scripted improv. We recorded the improvisation and had the best of it typed up – so that you were no longer doing improv, you were doing scripted material based on improv.”

He added: “Stanley never did any improv other than with Peter, but he was sensible enough to realise that when you hire actors, you’re hoping that they bring something with them.”

While filming the Pitch Perfect trilogy, Rebel Wilson said her contract included rules around maintaining her weight for the role of Patricia “Fat Amy” Hobart.

The actor explained on the Call Her Daddy podcast that she didn’t begin her weight-loss journey until after the films had finished, as she was expected to stay within a certain weight range while playing the character.

“I did wait until ‘Pitch Perfect’ seemed like it was over,” Wilson shared. “I couldn’t lose a massive amount of weight because it was in the contracts for that movie. You can’t lose — I think it’s not more than 10 pounds or gain more than 10 pounds. You have to kind of stay at the weight. It’s in your contract.”

When directing Maestro, Bradley Cooper introduced a surprisingly strict rule: no chairs were allowed on set.

Explaining his unusual approach, Cooper told Spike Lee for Variety: “But when I direct, I don’t watch playback. There’s no chairs. I’ve always hated chairs on sets; your energy dips the minute you sit down in a chair.”

Cooper also revealed that he banned “video village”, the area where directors and key crew members watch monitors during filming, adding: “I hate that.”

But it's not just Cooper who isn't a big chair fan. Apparently, Nolan isn't either. 

“He doesn’t allow chairs,” Hathaway told Variety, “and his reasoning is, if you have chairs, people will sit, and if they’re sitting, they’re not working. I mean, he has these incredible movies in terms of scope and ambition and technical prowess and emotion. It always arrives at the end under schedule and under budget. I think he’s onto something with the chair thing.”

However, Nolan's rep later clarified the chairs Hathaway was referring to were "directors’ chairs clustered around the video monitor, allocated on the basis of hierarchy not physical need."

Marvel became so determined to protect its biggest plot twists that some actors were no longer given full scripts. Instead, the studio reportedly used fake pages and incomplete scripts to prevent leaks.

Director Joe Russo told io9: “It’s important for us that we protect the story at all costs. And we just felt it would be best if people just didn’t know the whole story and be easier for them then to talk about it and say ‘I wasn’t given the script.’”

In fact, things were so under wraps that Tom Holland didn't actually know who he was fighting in Avengers. 

"There is one moment in Avengers where I don't know who that person is. And I'm fighting him, and there's nothing more embarrassing than pretending to fight a 'monster' in front of 200 people, in Spandex," Holland shared. "You know, literally like dodging stuff and trying to web him. They're all like, 'That's Great Tom, more energy. More Energy. Jump Jump.'"

While directing Severance, Ben Stiller introduced a strict no-phones rule inspired by lessons he had picked up from other directors.

While acknowledging that crew members sometimes need phones for work, Stiller said he didn’t want them distracting actors during performances.

“I like no phones anywhere near the eyeshot of the actors,” Stiller shared. “My least favourite thing is to see a dolly grip guy hunched down while an actor is acting their brains out, and he’s scrolling or whatever. It drives me crazy.”

Additional photo credits: Aalok Soni (Getty Images)/NataKor (iStock)