Is any other kind of movie as disposable as the slasher sequel? The Roman numerals at the end of their names even code them as factory product, fresh off the assembly line. They tend to be about 90 minutes long, rigidly formulaic, and instantly forgettable. With only a handful of exceptions, their (mostly young, mostly white) casts are interchangeable, and the same goes for their screenplays—“derivative” may be too gentle a word. Yet, thanks to a terminal case of morbid curiosity, I’ve watched dozens of ’em. Devoured ’em like popcorn. They’re not especially gratifying as art or entertainment; in fact, most are hacky, dull, and repetitive. But if you want to see how filmmakers wrestle with restrictive blueprints, low budgets, and fickle audiences… well, these movies have their pleasures.

The Friday the 13th movies, for example, are like Ozu dramas or Mondrian Compositions, these subtle variations on a theme. In this case, that theme is “Jason Voorhees kills everyone,” and part of each sequel’s pleasure lies in identifying those variations. How do you tell the same story over and over again without boring your audience? You tell it in 3D (Friday the 13th: Part III) and constantly thrust pitchforks and harpoon guns at the camera. Or you put it on a boat (Part VIII). Or you put it in outer space (Jason X). Honestly, the Friday the 13th movies could be titled like Friends episodes: The One Where He Has a Bag on His Head, The One Where Corey Feldman Kills Him, The One Where He Fights Carrie, etc., etc. Beyond these cosmetic differences, the films are near-identical, both in terms of plot structure and quality. (The latter metric staying at “not very high” for the duration of the series.)

Taken together, these films constitute a 19-hour saga as rhythmic and ritualized as its ki-ki-ki ma-ma-ma leitmotif. And taking them together, I just have to marvel at their collective contempt for spatial and narrative coherence, not to mention their shameless acts of self-cannibalism. Cat scares, roadside kills, disemboweled swimmers, bodies flung through windows: this is eternal recurrence localized entirely within rural New Jersey. On an individual level, however, each Friday the 13th entry instills a numbing sense of deja vu. My favorites are the most idiosyncratic ones: A New Beginning and Jason Goes to Hell, parts five and nine respectively. The former opens with a Fulci-esque graveyard scene, often gets distracted by the bizarre lives of its secondary characters, and has a twist ending Scooby-Doo would spit on. Jason Goes to Hell, the only Friday the 13th movie of the ’90s, is nothing but twists, retcons, and non sequiturs; it’s certainly not “good,” but at least it’s delirious.

Maybe it’s silly to prize delirium in a subgenre notorious for its homogeneity, but I get so tickled by slasher sequels that indulge in a little weirdness or, heaven forbid, warmth. Like the Nightmare on Elm Street movies, where reality is slippery and death is just a few seconds of shut-eye away. The series itself gets bad quickly, but its gory set pieces stay evocative: teenagers are fused with their motorcycles, reduced to pizza toppings, pulled into video games they can’t win, turned into comic book characters and then sliced to ribbons. It’s “high school sucks and parents don’t understand” blown up to tremendous, gory size. The only way out of this teenage nightmare? Solidarity. Indeed, the Nightmare movies are consistently the most teamwork-oriented of slashers, a refreshing shift from seeing kids picked off one by one until only the “final girl” survives. (This is that “warmth” I spoke of.) In the third and best Nightmare, subtitled Dream Warriors, a little sentimentality even blossoms up through the film’s blood-soaked carapace. This is no mere slasher movie; it’s a Reagan-era blend of afterschool special, action movie, and charnel house.

Of course, I’d be remiss to discuss the slasher cycle without a mention of Halloween’s myriad sequels. But I hesitate, because I kinda pity the series. Less consistent than the Friday the 13ths, less phantasmagorical than the Nightmares, the Michael Myers movies also have the misfortune of following John Carpenter’s original—the model for lean, low-budget horror. If this built-in redundancy sullies even the high-tension Halloween II, then heaven help something like The Curse of Michael Myers, which turns up four sequels later and stars a young Paul Rudd. At that point, the series still has its two mainstays—killing machine Michael and his personal Van Helsing, Dr. Loomis—but has long since squandered any momentum and is trudging through a morass of mythology. (Mythology that, like a sand castle at high tide, will be wiped away by Halloween H20.) Hence the pity: Halloween’s sequels exhibit glimmers of quality, but always retreat back into slasher tradition. As a result, they never carve out any unified identity beyond that deadpan William Shatner mask.

My favorite among the sequels, however, lacks even that. It’s the sui generis Halloween III: Season of the Witch, a conspiracy thriller that replaces Michael with the sinister Silver Shamrock mask company. Whereas Michael killed Haddonfield residents one by one, Silver Shamrock’s Samhain-loving CEO plots to kill all of America’s children in one fell swoop. It’s grim, yes, but laced with satire and as oddball as slasher sequels come. You couldn’t ask for a movie that undercuts viewer expectations more severely. Outside of Season of the Witch, the Halloween moment I treasure the most is the opening scene of #5, The Revenge of Michael Myers. Michael, we learn, has been hibernating ever since his last fake-out death a year earlier. Hibernating in a shack, that is, where he’s nursed by hermit. Once October 31st rolls around, he bolts up, kills the hermit, and walks back to Haddonfield. “Narrative logic?” laughs Halloween 5. “Fie!” Again, this may not be a “good” movie, but those first few minutes would leave even Luis Buñuel scratching his head.

The lesson here? Shoddy screenwriting can be a virtue as long as it makes a slasher movie stand out. Now that I’ve watched dozens of ’em, most of these movies have coalesced into a blur of knives and blood swirling in my head. I feel like I’m running in circles just trying to write about them. So anything memorable at all automatically becomes a strength. (Indelible performances, traces of visual style, and zippy pacing help too.) All of this explains why two franchises, Phantasm and Child’s Play, sop up most of my slasher love. Each has its dud entries, but both are unusually auteur-driven and blessed with spirited villains. Strip away their more macabre elements, and the Phantasm movies are a serialized Boys’ Own adventure; a Manichaean clash set against the desolate Pacific Northwest. There, evil is endemic… but still our heroes resist it, empowered by camaraderie and a sense of humor. The Phantasm movies envision a tiny light in the midst of vast darkness, making them a radical departure from their morally murky slasher brethren.

The Child’s Play movies, on the other hand, start out as conventional slashers. Their killer doll kills, is killed, and then lies dormant until the next sequel. The first three films lean heavily on two assets: 1) the fact that talking dolls are terrifying and 2) Brad Dourif’s bile-spitting vocal work as Chucky. But from there the series metamorphosed, culminating in the beautiful butterfly that is Seed of Chucky. The aggressively postmodern Seed doesn’t merely swallow its own tail—it gobbles it down in big, lusty bites. It turns slasher tropes inside out; it wallows in the a priori absurdity of a killer doll. Hell, it stages a full-scale 1950s melodrama in Jennifer Tilly’s attic. The movie’s vulgar, certainly, and its comedy is erratic, but it has chutzpah. How else could it so brazenly juxtapose old and new, revolution and tradition, pathos and cartoonish gore? As Seed of Chucky demonstrates, the “slasher movie” is only a template, a set of structuring ideas that tends to limit filmmakers’ imaginations but, on rare occasions, can also serve as a springboard for them. It’s a story syntax, a tool, and a resilient one at that; few others have been dissected and deconstructed so thoroughly yet lived to tell the tale. And, for better or worse, I suspect the slasher movie will always keep on rising from the dead.