Duality is a huge part of film. It is hard to think of any story that does not involve duality in some form, be it in characters or concepts. Let’s explore the most interesting examples of duality in film.

Visually, there is often a duality of colour in movies. The most obvious example is Mulholland Drive. Red and blue are rarely seen separately in the movie, once you notice it you see it in every scene.

Blue and red represents Betty and Rita, who are also inseparable as soon as they meet. Betty wears a blue sweater and Rita wears red. The blue box is further evidence that red and blue are a part of the puzzle.

The reason red and blue are always together is because Rita and Betty are the same person. One of them, perhaps Rita, is a figment of the other’s imagination.

The Aquaman trailer promises a duality of the colour red in the film. It appears multiple times in the trailer and it symbolises two different things. Hope and danger.

Mera, the love interest, has bright red hair. Red symbolises hope for Arthur Curry, this is the reason for the flare he is holding in one scene. It is literally a beacon for the creatures following them during a storm. However, red also symbolises danger for Arthur as Black Manta, the villain, wears a helmet with burning red eyes.

The most popular instances of duality are in a movie’s characters. In American Assassin, Mitch’s darkness and rage is threatening to send him down a dangerous road.

There is a duality between his mentor, Stan and his target, Ghost. His darkness could lead to him becoming either one of them. If he can learn to channel his aggression, he will no doubt become something like his mentor. If he does not learn to tame the animal inside he will become just like Ghost, an extremist.

Duality between two characters often signifies an internal struggle. In Alfred Hitchcock’s Vertigo, Scottie is tasked with ensuring the safety of a suicidal woman. He fails in his attempts to stop her suicide due to his chronic case of vertigo.

It is revealed that Mr Elster, the woman’s husband is actually murdered her. Elster is abusive control-freak towards women. Despite the fact that he initially wants the best for Madeline, the psychologically tasking case leads him to lose his mind. He ultimately becomes controlling and manipulative just like Elster.

Duality in film involves two characters each being a side of the same coin. They are usually full of similarities but directly opposed in agenda. Duality is a popularly used and effective device for drama.