There were a lot of talented people in the industry that worked on the set of Casablanca. Some of these being the performers, the director, the sound crew and the costume designers. However, the real main factor responsible for the film is World War 2. The whole film is based on the context of what was going on at the time. With it being made in 1942, the US had not entered the war yet and many saw it (and still see it) as propaganda for them to get involved. There are many references and mid-movie metaphors that are about the war and the film would have never been made if it wasn't for the war. Undoubtably, the performances were also key for the success of Casablanca. Humphrey Bogart was not used to playing a character like Rick but it is fair to say that he nailed it. With his sarcastic tone, his witty jokes and his relatable personality, Rick is a fan favourite in movie history. His chemistry with the other protagonist character, Elsa (played by Ingrid Bergman) is amazin...