The Story Was Purchased for $20,000
In 1940, playwright Murray Burnett co-wrote the movie and its characters when he and his writing partner Joan Alison wrote the play called ”Everybody Comes to Rick’s” and the setting was in Lisbon, Portugal. Having witnessed the political change that was occurring across Europe, the two writers intended to make a cautionary tale about the cost of fascism. The play they wrote was meant for Broadway, …but never made it.
Source: mubi.com
One reason it didn’t make it to the stage in New York was because of the implication that Ilsa (played by Ingrid Bergman) slept with Rick just to get letters of transit. Warner Brothers, however, certainly saw the potential and bought the script and all its rights for a record $20,000. Decades later, when Warner Brothers created a short-lived TV show based on the movie in the ’80s, Burnett sued them.