A Night in Casablanca storyline for the film was intended to be a direct parody of "Casablanca," with the characters having similar-sounding names to the characters and actors in the 1942 film. Groucho Marx has said that an early draft named his character "Humphrey Bogus", a reference to the leading actor in "Casablanca," Humphrey Bogart. Warner Bros. did not actually litigate, or even threaten to litigate, but it did issue a formal inquiry to the Marx Brothers concerning the plot and script of the film. The Marx Brothers exploited the situation for publicity, making it appear to the public that a frivolous lawsuit was
Casablanca (film) had turned down the lead role. Studio records make clear that Wallis was committed to Bogart from the start. Another well-known story is that the actors did not know until the last day of shooting how the film was to end. The original play (set entirely in the cafe) ended with Rick sending Ilsa and Laszlo to the airport. During scriptwriting, the possibility was discussed of Laszlo being killed in Casablanca, allowing Rick and Ilsa to leave together, but as Casey Robinson wrote to Hal Wallis before filming began, the ending of the film "set up for a swell twist