Everybody Comes to Rick's is an American play that was bought unproduced by Warner Brothers for a record figure of $20,000 (equivalent to $350,000 in 2024). It was adapted for film as Casablanca (1942), starring Humphrey Bogart and Ingrid Bergman. Written by Murray Burnett and Joan Alison in 1940, prior to the United States' entry into World War II, the play was anti-Nazi and pro-French Resistance. The film became an American classic, highly successful and ranked by many as one of the greatest films ever made.

Feeling they had not received full recognition for their contributions, Burnett and Alison tried to regain control of the property, but the New York Court of Appeals ruled in 1986 that they had signed away their rights in their agreement with Warner Bros. Under their threat not to renew the agreement when the copyright reverted to them, the film company paid them each $100,000 (equivalent to $240,000 in 2024) and the right to produce the original play. It was produced in 1991 at the Whitehall Theatre in London, where it ran for six weeks.

In the summer of 1938, while on vacation from his job as English teacher at a vocational school, Burnett and his wife Frances traveled to Vienna to help Jewish relatives smuggle money out of the country occupied by the Nazis since March of that year. Later, the couple visited a small town in the south of France, where they went to a nightclub overlooking the Mediterranean Sea. A black pianist played jazz for a crowd of French, Nazis, and refugees.

Burnett returned to the USA via the UK, staying a few weeks in Bournemouth. While there he started to make notes for his anti-Nazi play. In the summer of 1940, the 27-year-old teacher completed the play in six weeks with the collaboration of Joan Alison. They featured Rick, an American bar owner of the Café Americain in Casablanca, Morocco, whose European inhabitants, military personnel and refugees often frequent the café. Eventually, Rick helps an idealistic Czechoslovak resistance fighter escape with the woman Rick loves.

Soon after, writer Carly Wharton and actor Martin Gabel took an option to produce the play. But there was resistance since it might seem to some that Lois (Ilsa in the movie) "had slept with Rick in Casablanca in order to get the letters of transit".

When Burnett and Alison failed to find a Broadway producer, they sold the play to Warner Bros. for $20,000, considered a record for an unproduced play, especially by two unknown writers. A story editor, Irene Diamond, had read it in manuscript in New York, and recommended it to her boss, producer Hal B. Wallis, as "sophisticated hokum".

Warner Bros. gave the script for adaptation first to screenwriter Casey Robinson, who worked on the romantic pairing of Rick and Ilsa; twin-brother screenwriters Julius and Philip Epstein, who worked on the overall structure and dialogue; and screenwriter Howard Koch, who worked on the politics. Only Koch was with the project during filming, when he continued to write new dialogue and scenes. The title was changed to Casablanca.

The inclusion of "As Time Goes By" came from Burnett and Alison's play. The song, from 1931, had been Burnett's favorite when he was a student at Cornell. "As Time Goes By", written by Herman Hupfeld, was first performed by Frances Williams in the musical comedy Everybody's Welcome, which had played on Broadway from October 1931 to February 1932.