From The Making of Casablanca: Bogart, Bergman, and World War II:
The sixty-six pages of script, labeled Part I TEMP., were mimeographed on April 2. The Epsteins had written the first third of the movie, the section preceding the flashback to Rick and Ilsa’s Paris romance. Ilsa and her Resistance-hero husband had come to Casablanca, and at the end of the Epsteins’ script, Rick was sprawled drunkenly in his empty cafe, waiting for her to return.
“That first part was very close to the play,” Epstein says. “It was with the second half that we had trouble.”
Those sixty-six pages mirror the final movie. The Epsteins even begin with a spinning globe, an animated map, and a description of the refugee trail that leads to Casablanca. Everybody Comes to Rick’s took place inside Rick’s Cafe, and Rick was the first character to be introduced. The Epsteins start by creating the feel of Casablanca: A man whose papers have expired is short by the police; a pickpocket warns his victims that vultures are everywhere; refugees look up longingly as an airplane brings the Gestapo captain (a few scripts later he was promoted to major) Strasser to Casablanca and lands beyond a neon sign that reads RICK’S. Inside the cafe, a dozen desperate refugees try to buy or sell their way to freedom. Rick is not introduced until page 15, when a hand writes “Okay — Rick” on the back of a check and the camera pulls back to a medium shot of Humphrey Bogart. And the plot is driven by an invention of the Epsteins: the Letters of Transit were being carried by two German couriers who have been murdererd.
Of the four major characters in Everybody Comes to Rick’s, only the noble Victor Laszlo remains essentially the same in the movie. Rick, who in the play is a self-pitying married lawyer who has cheated on his wife, takes on Bogart’s persona of wary, hooded toughness. Says Jules Epstein: “Once we knew that Bogart was going to play the role, we felt he was so right for it that we didn’t have to do anything special. Except we tried to make him as cynical as possible.”

