Trivia

This film was improvised from a 56-page outline. Each scene was shot in sequence and built upon the previous scene. To aid in this experiment, the film's producers had a video-camera tube attached to the Panavision camera and connected to an Ampex studio videotape machine, allowing the actors and crew to review what they had just filmed. According to a contemporary article in Daily Variety this was one of the first productions to use a video camera in this matter. This eliminated the time and expense of developing the film and showing the "rushes" the following day. The cost of this new technology was $1100 per day, but director Blake Edwards said the system saved the production many times that amount by avoiding costly resets and re-shoots on following days.

Associate producer Ken Wales nearly drowned during filming, after stuntman Dick Crockett shoved him into the foam-filled swimming pool as a joke. No one had told either man that the foam was actually designed for use by firefighters and absorbed oxygen in order to help put out fires, meaning that Wales couldn't breathe even when he was above the water. He had to be rescued by a couple of stagehands.

Hrundi involuntarily blowing up the fort was possibly inspired by a similar real-life occurrence which happened a couple of years before, during the shooting of a now iconic scene of El bueno, el malo y el feo (1966). Due to a misunderstanding, a huge bridge was blown up while the cameras were not filming, enraging director Sergio Leone; the bridge had to be rebuilt.

This film was hugely popular in India. The late Indian Prime Minister Indira Gandhi was a fan and was very fond of repeating Bakshi's line "In India we don't think who we are, we know who we are!" Additionally, legendary Indian director Satyajit Ray was a fan and wanted to cast Sellers as a Marwari businessman in his film "The Alien". Sellers eventually pulled out of the project.

The interior of the mansion was a massive indoor set built at "The Lot" Studio, located at 1041 N. Formosa Avenue in West Hollywood, CA, not at MGM studios in Culver City.