Friday the 13th [Sean S. Cunningham, 1980]:
While not a great piece of cinema in the conventional sense, the stature of Cunningham's film is really elevated above other the icons of the slasher sub-genre by virtue of its third act reveal. The psychological and sociological implications of the killer's identity provide an emotional weight and dramatic complexity too often missing from films of this nature. Further, the appropriation of influences, from Mario Bava to John Boorman's film of Deliverance (1972), are applied incredibly well.
What’s fascinating about Friday the 13th, perhaps more so than films like Halloween (1978), Prom Night (1980) or My Bloody Valentine (1981) is that it almost becomes a cinematic Rorschach test. If you’re a liberal, you might see it as a film about youth being punished by the older generation for the perceived sin of enjoying themselves. If you’re a conservative, then you might see it as a retribution against the amoral, out-of-control youth debasing themselves and American family values. It's a film that taps into the politics of the late 1970s and early 1980s, as well as the cultural mood of the era.
The context is vague and indirect, but still apparent enough that it can be read into the development of the characters and the themes of the film: i.e. loss of innocence, parental responsibility and wayward youth (as well as the usual horror film connotations to voyeurism and objectification, sex and death, which are all apparent themes.) Similarly, the isolation of the setting as both a physical and metaphysical space, the nightmare of the final girl, the way fear creates wounds, the rebirth of the character “Jason” as he emerges from his watery grave to wreak havoc across further sequels, all seem (intentionally or not) self-reflexive.
More than anything the film also provides something of a reminder that early slasher films were essentially "a vibe." Later, there was an expectation that someone had to die on every third page of the screenplay, but here, as in Halloween, or something like Bava's proto-slasher film A Bay of Blood (1971), the film is content to luxuriate in the atmosphere of its lakeside setting, in the dumb teen preoccupations and concerns of its characters, and in the comings and goings of the staff attempting to get the summer camp up and running.