What common trope is found in classic slasher movies?

The common trope found in classic slasher movies that resonates strongly with the genre's conventions is the murder of sexually active teens. This theme runs throughout many slasher films and serves multiple narrative purposes. It often reflects societal anxieties around youth, sexuality, and morality. In these stories, characters who engage in sexual behavior are frequently depicted as either being actively pursued by the killer or are among the first victims, establishing a kind of moral lesson that links promiscuity with punishment.

This trope creates tension and instills fear in the audience surrounding the vulnerabilities of youth, while also serving as a narrative mechanism to delineate between characters who are deemed "innocent" and those who are considered "guilty" of moral failings. As this theme recurs in classic slasher films, it contributes to the overall framework of the genre and character archetypes frequently seen across various titles.

While other options such as the identity of the killer being revealed and the survival of the final girl are also significant elements in slasher films, the specific focus on the murder of sexually active teens is particularly emblematic of the genre's moralistic undertones.