Like a boxer who weighs less than his opponent, Groucho Marx circles the great movie moguls—the Warner Bros.—baiting them, drawing them out, blinding them with his fancy footwork in his response to a letter from the studio forbidding the Marx Brothers from using the word “Casablanca” in the title of their upcoming film, A Night in Casablanca. Rather than take Warner Bros. on directly, Groucho Marx jabs and feints—humorously, of course—until Warner Bros. couldn’t possibly take its own claim seriously.

Marx opens the letter with an intentional misunderstanding, the first way he highlights the absurdity of Warner Bros.’ threat of legal action. He claims not to have understood that Warner Bros. had conquered the city of Casablanca until he received their “long, ominous legal document.” It’s not a big leap from there for Marx to imagine Ferdinand Balboa Warner, conveniently named after a real explorer, claiming the city of Casablanca by “raising his alpenstock.” The image conjures up scenes from the lavish epics of early Hollywood, casting Warner as Moses in Cecil B. DeMille’s The Ten Commandments. Marx extends his misunderstanding by imagining that the studio’s main worry might be the trouble that the “average movie fan” will have in distinguishing Ingrid Bergman from Harpo Marx. Humbly, Marx says he “certainly would like to try.” This slightly salacious offer reinforces the silliness of Warner Bros.’ worries: Bergman was beautiful, blonde and dignified; Harpo Marx was a short, bewigged, mute clown.

Marx creates a sense of familiarity, which serves his purpose by reminding his audience—Warner Bros. and their legal team—that they’re all in the same boat, moviemakers with similar cultural knowledge, even shared heritage. Using classic Marx Brothers absurdist humor Groucho claims that he and his brothers—the Marx Brothers—have been around longer than Harry and Jack have and that they might have more right to use the word “Brothers” in their name. He piles on a list of other sets of brothers: “the Smith Brothers” (of cough drop fame), “the Brothers Karamazov” (title of a nineteenth-century Russian novel), a baseball player with the last name of “Brouthers.” He even riffs a bit on the song “Brother, Can You Spare a Dime?” He gets even more personal, addressing each Warner brother by name: “Now Jack, how about you?”, “As for you, Harry,” and throws in some well-known examples of Harrys and Jacks, just for good measure. Unwilling to stop, Marx even questions the right of Warner Bros. to name its workplace “Burbank studio,” suggesting—“pure conjecture, of course”—that Luther Burbank’s survivors might not be happy to be associated with the Warner Bros.’ body of work. One can imagine the effect of Marx’s onslaught of examples on the movie studio’s large and serious legal team, who also come under fire.

Content to let the logic of his defense rest, Marx gives Warner Bros.’ legal team a break, suggesting that the letter was the brainchild of a young lawyer “hot out of law school, hungry for success and too ambitious to follow the natural laws of promotion.” He claims sympathy and admiration for the heads of the legal department, “fine fellows with curly black hair, double-breasted suits and a love of their fellow man,” a formulation he uses twice—the second time slightly truncated and ending in “etc.” Effortlessly, Marx calls up a vision of mindless automatons, led astray by the “pasty-faced legal adventurer” whom Marx calls responsible for the possible “bad blood between the Warners and the Marxes.” Here he reinforces that bond between moviemaking families—“brothers under the skin”—and highlights once more the absurdity of imagining that the reputation or box office receipts of Casablanca, the 1942 Academy Award winner for Best Picture, will be sullied by a film made by the likes of Groucho and his brothers.

In this hilarious letter—and in the two letters that followed—Groucho Marx underscored the ridiculousness of comparing the classic Casablanca with the silliness of a Marx Brothers film in very much the style of his own films. Fast, clever, not especially logical, but certainly tireless, Marx wore out his bigger opponent. It took two more letters from Marx to get Warner Bros. off his back: each one outlined plots that were so far-fetched as to be nearly incomprehensible, and Warner Bros. finally gave up.