Hard Boiled was John Woo's last Hong Kong film before his transition to Hollywood. After making films that glamorized gangsters (and receiving criticism for doing so), Woo wanted to make a Dirty Harry styled film to glamorize the police. After the death of screenwriter Barry Wong, the film's screenplay underwent constant changes during filming. New characters such as Mad Dog and Mr. Woo were introduced, while the original plotline of a baby poisoning psychopath was cut.