* BigBudgetBeefUp: While crafted as a loving tribute to the often-dirt cheap medium of silent film, the sheer scale, ambition, and length of Edwards' story made the film, at the time, the most expensive comedy in history (roughly $90 million when adjusted for inflation).[[note]]Part of this was due to contractual negotiations; after Curtis's agent got him signed for $25,000 more than Lemmon and Wood, he proceeded to then advocate for them to all be paid equally.[[/note]]
* DuelingWorks: The far more commercially and critically successful ''Film/ThoseMagnificentMenInTheirFlyingMachines'' had been released not a month prior by Fox, which hurt the film in both departments (though it still made over double its budget at the box office).
* EnforcedMethodActing: When Professor Fate uses the railroad rocket-car for his second stunt, depending on who you ask either Blake Edwards decided not to tell the extras just how large of a pyrotechnic load was packed in the engine, or he didn't realize it himself. When the crowd scatters, what you see is genuine shock and terror on the faces of the extras.
* NonSingingVoice: Robin Ward sang "The Sweetheart Tree" instead of Creator/NatalieWood. Wood sang "My Country 'tis of Thee" herself earlier on...you can tell because she sounds off-key.
* ProductionPosse: Creator/BlakeEdwards, director and co-writer, apparently brought along a good number of the personnel he'd previously worked with on his [[Series/PeterGunn television]] [[Series/MrLucky shows]], most prominently Music/HenryMancini and Ross Martin.
* ThoseTwoActors: Creator/TonyCurtis and Creator/NatalieWood in their third (and final) film together, and Curtis and Creator/JackLemmon in their second of two. Although, ask anyone to name a Tony Curtis/Jack Lemmon film, they'll probably think of [[Film/SomeLikeItHot the other one]].
* WhatCouldHaveBeen: Creator/CharltonHeston was originally offered the role of The Great Leslie. He considered it a "funny script" but had to turn the part down when the production schedule for ''The Agony and the Ecstasy'' (1965) was delayed.