- Executive Meddling: About a hundred years after Shakespeare died, an English theatre impresario (probably Colley Cibber) added an extra "witches" scene to Act III which was later assumed to have been part of the original play. (After the witches' "double, double, toil and trouble" speech, Hecate and three other witches show up randomly, sing a song called "Black Spirits", and vanish). This is never mentioned again. Most versions of the play produced before about 1970 include this scene; most since leave it out.
- No Budget: The play can be thrown together on the cheap. That's part of the reason it's so dangerous. The easiest way to conjure up that spooky Highland atmosphere is with darkness, and lots of it. Now just throw in lots of daggers and swords, and long, heavy cloaks that everyone can trip on and, yes, you can see the problem.
- Cultural Translation: A 1970 Zulu-language adaptation by South African playwright Welcome Msomi, called uMabatha, adapts the play into Zulu tribal culture of the early 19th century (around the reign of the famous King Shaka). Actor and theater critic Peter Ustinov remarked that until reading uMabatha, he did not understand Macbeth. Nelson Mandela remarked on the similarities between Macbeth and King Shaka.
- The 8th among the royal descendants of Banquo who appear in the witchcraft induced vision in Act 4 is supposed to be King James I of England, who was believed to be 8 generations removed from the real life Banquo. Somewhat ironically, the current British royal house is actually descended from the Thanes of Glamis, the old fief belonging to Macbeth himself in the play, since the Queen Mum, the mother of the current Queen Elizabeth II, is of a Scottish noble family who has been the real Thanes of Glamis since 14th century and spent her childhood there.
- Trope Namers: Eye of Newt, Lady Macbeth, No Man of Woman Born, Out, Damned Spot!
The 1948 Film:
- Acting for Two: Each of the witches was played by an actor who played someone else in the film; Brainerd Duffield played the First Murderer, Peggy Weber played Lady Macduff and Lurene Tuttle played the Gentlewoman.
- Cross-Cast Role: One of the witches is played by Brainerd Duffield - a man. As noted below, Orson Welles's daughter played Macduff's son.
- Directed by Cast Member: Orson Welles directs and plays the lead role.
- Dueling Works: Laurence Olivier released an adaptation of Hamlet the same year, and Orson Welles withdrew this film from Cannes to avoid competing with it. Laurence Olivier had planned to make a Macbeth film initially, but dropped it when it became clear that this one would come out first.
- Germans Love David Hasselhoff: The film was met with apathy in Britain and America, but it was a huge hit elsewhere. In France especially it was regarded as a masterpiece.
- Real-Life Relative: Macduff's young son was played by Orson Welles's daughter, Christopher Welles.
- What Could Have Been: Vivien Leigh was the first choice for Lady Macbeth but her husband Laurence Olivier refused on her behalf. Agnes Moorhead was also courted for the role but turned it down.
The 1971 Film:
- Box Office Bomb: The budget for the film was $2.5 million but it ballooned by several hundred thousand dollars in production. It only took in just over $3 million at the Box Office.
- Creator Breakdown: It's widely assumed that the film's Bloodier and Gorier nature was influenced by the real life murder of Roman Polanski's wife Sharon Tate. When some crew members suggested toning the film down, he responded "I know violence. You should have seen my house last summer."
- Name's the Same: The little girl who played Lady Macduff's dead daughter was asked what her name was playfully by the director while he was smearing fake blood on her. She replied "Sharon".
- Role Ending Misdemeanor: Role preventing misdemeanour in this case. Marianne Faithfull screentested for the part, but was rejected after her heroin use was discovered.
- Same Language Dub: Terence Bayler's dialogue is dubbed.
- Troubled Production: Production suffered lots of setbacks due to bad weather delaying filming, special effects malfunctioning and Roman Polanski insisting on doing several long excessive takes. Production ran six months over schedule and $600,000 over budget.
- What Could Have Been:
- An elaborate bear-baiting scene was planned but due to several complications it ended up cut.
- Tuesday Weld was the first choice for Lady Macbeth, but she refused to do nude scenes.
The 2015 Film:
- Ability over Appearance:
- Although Lady Macbeth's nationality is never officially stated in the play, she's assumed to be Scottish. She's played by French actress Marion Cotillard Not Even Bothering with the Accent - because she's an Oscar winning actress who is otherwise perfect for the part. The change does have a historical justification; Scotland has had many French queen consorts, making it plausible that Lady Macbeth could be French.
- There were just three witches in the original play. The director liked the seven-year-old Amber Rissmann so much that he created a fourth witch just to accommodate her.
- Dueling Works: Another Macbeth adaptation - The Moving Forest was released in 2015.
- Fake Scot: Irish actors Michael Fassbender and Jack Reynor as Macbeth and Malcolm, and the English David Thewlis as Duncan.
- The Other Marty: Natalie Portman was cast as Lady Macbeth initially, but dropped out just before production began.
- Promoted Fanboy: Marion Cotillard always dreamed of playing Lady Macbeth, and had assumed she'd only play her on the stage in France. Jack Reynor was likewise a fan of Marion and said it was an honour to actually work with her.