Both films contains examples of:
- Adaptation Displacement: There was a book?
- Complete Monster: Max Cady from both versions. See below for details.
- "Weird Al" Effect: The theme is quite possibly better remembered as Sideshow Bob's theme in The Simpsons, ever since the Parody Episode "Cape Feare".
- Complete Monster: Robert Mitchum's Max Cady is a smug, slimy sociopath who went to jail for rape and returns later to destroy Sam Bowden, a man who testified against him. He kills the family dog, relentlessly stalks the family and destroys those around them, planning to rape Bowden's wife and daughter before he kills them. He also rapes and beats an innocent woman for no reason just as a means of asserting his power over her and Bowden's helplessness to do anything. He's out for nothing but revenge and doesn't care that he deserved to go to jail for what he did.
Cady: Speakin' about your wife and kid, I got a little caper planned for them...I got something planned for your wife and kid that they ain't never gonna forget.
- Values Dissonance: A mild example: when discussing how Cady could possibly think he'd get away with raping Bowden's daughter, Bowden concludes that Cady knows that, while her testimony would put him away for life, the devastating experience of having to testify and answer questions about it would be so traumatic that the Bowdens would let Cady go free before subjecting their daughter to the questioning. Nowadays, most people with knowledge of sexual assault cases (which Bowden has) actually encourage victims to testify for their own benefit as much as to help convict the assailant; modern psychiatric help stresses the cathartic effect of testifying against the rapist, and so, however upsetting it may be at the time, the Bowdens stopping their daughter from speaking out against her attacker would be unlikely to help her long-term recovery. (There's also the fact that today, many countries have laws allowing a child to testify by video camera rather than having to be in the same room with their attacker, but that's more a case of Technology Marches On rather than this trope).
- Since 1962, awareness of stalking has increased and the law now offers much stronger protection for its victims. With the known history the two characters share, it would've been relatively easy to prove Cady was harassing and following Sam with malicious intent which would've netted him a trip back to prison for his trouble.
- Vindicated by History: The film was such a flop on release, that it ended Gregory Peck's production company. Now it's considered a classic thriller.
- Complete Monster: Robert De Niroís version is a mad dog Knight Templar who also was released from jail for rape. He brutally rapes and maims a friend of the target of his anger, kills Bowden's housekeeper and his PI, fatally poisons the family dog, and tries to drive Bowden insane before planning to rape his wife and daughter here as well. He claims throughout the movie that he's all about the law and how he looks in God's eyes, and yet does not admit that he deserved his prison sentence even though he might have gotten off had Bowden done his job properly. He doesn't care about justice and proves to not only be a raging hypocrite out for revenge, but simply deciding to hurt people because he likes to do so.
- Foe Yay: Danielle was not scared of Cady. She seemed a little fascinated by him, until the end.
- Genius Bonus: How many viewers were able to understand all of Cady's literary references, especially those to The Divine Comedy?
- Moral Event Horizon: Cady's attack on Lori, Bowden's friend. See Nausea Fuel Below.
- Narm: Cady's death. Before he starts "screaming in tongues" about the promised land, it really just sounds like he's saying several random syllables quickly, most of which are "bloh de blah".
- Nausea Fuel: Cady biting off a chunk of a Lori's face.
- Strawman Has a Point: Bowden gets the chief of police to try to drive Cady out of town before Cady has done anything illegal. Cady hires a lawyer who is portrayed as fussy and over-liberal, but who makes the entirely legitimate point that Cady is being harassed for no reason. Of course, Cady does not stay innocent for long.
- Tough Act to Follow: This had the bad luck of being Martin Scorsese's first film after Goodfellas.