When you have more than one screen adaptation of a novel, usually one is more faithful to the novel than the other. However, in the case of The Maltese Falcon, it has two pretty accurate adaptations. The first version, released in 1931 and stars Ricardo Cortez, Thelma Todd, and Bebe Daniels, does a pretty good job of sticking to the source material. However, the 1941 Humphrey Bogart version is an even more accurate representation of the book. It doesn’t stick to the novel exactly, but most of the dialogue is taken verbatim and the key story elements are kept in tact.
Most of the differences are pretty subtle and probably were changed for the sake of pacing. For example, in the movie Sam finds out about La Paloma after he wakes up in Gutman’s hotel room and starts looking around the room. It’s a much more drawn out process in the book. In the book, Sam finds out Miss O’Shaugnessy didn’t go to Effie’s apartment like she was supposed to. Instead, she had the cab stop to get a newspaper, then she asked to be brought to the ferry building. So Sam gets a copy of the paper in question to look for clues, but doesn’t figure it out until he starts snooping around Cairo’s room and notices that the newspaper section with ship arrivals was of particular interest to him. Although there’s nothing wrong with the way that part plays out in the book, if it were filmed that way, it would have slowed the movie down. Another difference is that the character of Gutman’s daughter is completely absent from the Bogart movie (as well as from the Ricardo Cortez version, for that matter), but she wasn’t exactly a vital character in the book.
A lot of the other changes were definitely made because of the production codes. What’s interesting about that content is that neither the 1931 or the 1941 version gets it exactly right. The 1931 version tends to be a bit more scandalous than the book was, but it does include things that were in the book that couldn’t be included in the 1941 version. There’s no way the 1941 version could have gotten away with the scene where Spade strip searches O’Shaugnessy after noticing that $1,000 of the $10,000 Gutman promised him was missing, but it was in the 1931 version. The 1941 version also really had to downplay the fact that Cairo and Wilmer were both supposed to be gay, the 1931 version made that much clearer. In the book, when O’Shaugnessy finds out that Sam has been talking to Cairo and that he’s prepared to offer more money than she can, she offers to sleep with him and proceeds to spend the night at Sam’s apartment. When it comes to that part in the 1941 version, O’Shaugessy can’t offer herself to Spade or spend the night, so Sam just kisses her instead. As for Spade’s affair with Iva Archer, the 1941 version actually depicts what went on more accurately than the 1931 version. The 1931 version made that affair more salacious than the book described. First of all, the book made Iva Archer out to be a little past her prime, which Thelma Todd most certainly was not. There also weren’t any scenes involving Iva showing up at Sam’s apartment and finding O’Shaugnessy wearing her kimono nor were there any of Miles listening on the extension while Sam and Iva set up a tryst.
I really enjoyed reading The Maltese Falcon and I think anyone who likes either movie version would, too. Like I said, what you see in either movie version is pretty much what you get in the book. And since it’s not a terribly long book, either, I definitely recommend reading it. As for which movie version I prefer, I think it goes without saying that the Humphrey Bogart version wins hands down. The Ricardo Cortez version is good, but it doesn’t have the flawless cast and direction that the Humphrey Bogart version did. I always loved the cast of the Bogart version, but while I was reading the book and got to read exactly how each character was described, I feel like that version had some of the most perfect casting of all time. Nobody will ever make a better Sam Spade than Humphrey Bogart.