へぇ、あのセリフももとはアドリブだったんだ。
http://www.purpleclover.com/entertainment/4792-ultimate-ad-libs/item/casablanca-1942/
Casablanca (1942)
“Here’s looking at you, kid.”
Humphrey Bogart first said this off camera, while teaching Ingrid Bergman how to play poker between takes, and then the phrase came out spontaneously during one of the Paris flashback scenes. It would become a recurring line in the movie, repeated most memorably near the end.