Why was the zombie girl the only one able to go from the cabin in the upper level to the lowest one in the Purge scene, when every monster has the goal of simply killing humans? Because her mission is to go for the main characters, and to accomplish that, she has a lot of Patience.
Many of the problems the evil organization suffers are heavily implied to be caused by the gods themselves. Presumably they are getting bored with the old formula. And what happens when a horror franchise gets tired? Aliens vs Predators, Freddy vs Jason, CROSSOVERS, such as every monster getting loose at once. The gods deliberately caused a situation where everything would be released.
Alternatively, perhaps crossovers occur when two or more of the basement objects are activated at the same time. We were, after all, very close to getting that this time.
When Marty "dies", the whole operation is interrupted by an earthquake, which Sitterson attributes to the enjoyment of someone "downstairs." However, it never happens when anyone else is killed because they're NOT actually happy. The earthquake comes after Hadley tells the Eldritch Abomination that "the fool" is dead when he had really survived.
In addition, how could the controllers possibly make the mistake of thinking that Marty died when it is clearly shown that they are monitoring the vital signs of all the participants? It is demonstrated that the victims are not aware their vitals are being monitored (topless Jules is clearly not wearing a heart monitor or a blood pressure cuff) meaning it would have to be some kind of implant or imbibed device. Therefore, when Marty is dragged into the woods and stabbed by one of the Buckners, his injuries (which are numerous) must have damaged the device enough that the controllers read him as dead.
Or possibly the five of them were tricked into ingesting tiny monitoring/tracking devices shortly before their trip, and Marty puked his up from his injuries and/or the ickiness of having to dismember a zombie. Dana barfs when she's getting the snot kicked out of her at the dock as well, after which the facility's personnel seem unable to keep tabs on the location of either of them.
The song playing while Dana is brutally almost-killed in the background is "Roll With the Changes" by REO Speedwagon. Lyrics include "so when you're tired of the same old story/ oh, turn some pages/ I will be here when you're ready to roll with the changes." Very sneaky, Joss.
Why did Patience pass Dana instead of killing her? The monsters still follow the "rules" of the ritual; in the beginning, the others only attacked Kurt when he tried to protect Jules, who was supposed to die first. Since Marty, the Fool, was still alive, Patience went after and tried to kill him instead of attacking the Virgin. Also, because in the horror film narrative that the Redneck Zombie Torture Family would be following, if their story was a movie, Patience would have shown up towards the end to help Dana, the Final Girl, figure out how to lay the Buckners to rest. Because the usual flow of narrative (the way the ritual must unfold, as well as the plot of the Buckner's "movie") has been disrupted, Patience is irrelevant and never fulfills her role.
Or Patience knows if Dana didn't die from her werewolf mauling, she's now going to turn into one.
Why a unicorn? Because it doesn't have to be specially trained to leave The Virgin unharmed — popular depiction is that only a virgin can tame and ride unicorns.
Is the unicorn really that evil? After all, there are also myths about unicorns being good but ultimately wild creatures who only kill evil people — and the facility was certainly full of those. It could also be set on the 'sinful' teenagers. Thanks to the Enforced Trope that's going on, who knows how it would have worked.
Old-school unicorns were killers of anybody who got near them but virgins, though. For the Facility's purposes, they'd make sure to use an old-school one, because there's no guarantee that all the Sacrifices would be 'sinful' enough to merit death, e.g. one might prefer to heed the Harbinger's words and avoid the cabin but get out-voted four to one, then linger upstairs rather than enter the cellar with the others.
Fridge Logic hits here, though: If The Organization has to resort to using fake virgins these days, then a unicorn is not a great choice of monster to keep around. Presumably, the unicorn, unlike the Ancient Ones, knows the difference between a fake virgin and the genuine article. If that monster had been released, things might have gone south much faster.
In the opening scene, Hadley complains to Sitterson that his wife is over-preparing for their planned pregnancy, which has yet to occur. He says that the more prepared you are to have a child, the less likely you are to have one. This foreshadows how being Crazy-Prepared will make you vulnerable to the tiniest deviations that slip through all your perfectly-crafted plans. The agency prepared for everything — except for the "ineffectual comic relief" just barely escaping what, a few inches to the side, would have been a fatal wound, which snowballed into worse and worse consequences later on.
It's also very subtle foreshadowing: Hadley's wife has gone so far as to put childproof latches on all the kitchen cupboards, but Hadley is tired of the inconvenience and is planning to "liberate" his shelves by taking off the latches. The Facility itself has a lot of carefully-latched cupboards full of monsters, and by the end of the night, Dana's and Marty's frustrations will see the contents of all of those liberated...
The tunnel fails to collapse, and the demolitions expert claim it was "a power glitch from upstairs." It's easy to assume they're referring to the unseen directors, considering the controller's references to "upstairs" meaning management and "downstairs" meaning The Ancient Ones, but what it really was is Marty, who survived the zombie, found the maintenance panel, and had since been fooling around with the wires from literally upstairs!
Marty's bag is that he's the only one who's intuiting the nature of the scenario around them. When they go into the cellar, he immediately gravitates to the film strip. Holy shit. Of course he did. That's the movie going one step more meta than before.
The Ancient God's arm looks strangely human-like for an Eldritch Abomination. However it makes sense considering the Gods are actually a representation of the audience.
This film is actually a metaphor... for itself. The controllers have been going through the monotony of a ritualistic sacrifice to assuage the "Gods" (read: audience), until things don't go according to the formula and then it changes the world forever. The giant hand at the end is a symbol for the audience rebelling against the cliched and formulaic horror movie genre.
But, the Ancient Ones rose specifically BECAUSE they didn't get their cliched and formulaic movie...
The voyeuristic, first-person view that is part of slasher movies and dumb actions of the victims has caused audiences to want the clueless leads to die in many of them. The more this movie goes along, the more you want the leads to die for a different reason.
At the very end, when the Ancient Ones' hand comes down and engulfs the screen, It could be a representation of the audience facepalming at the film.
In the opening scene, it is mentioned that the last big upset for the organization happened in 1998. What happened in 1998? The Last Broadcast was released and is usually looked to as the first of the modern found footage horror genre.
Or... as mentioned in the main wiki, Rodriguez' The Faculty was released, where everybody survives because of homemade drugs (it's mentioned that the only failure, in '98, was the Chem department's fault).
As the finale shows, the Controllers have all sorts of cool and exotic critters at their disposal to terrorize and kill a bunch of kids. But in a film that's all about deconstructing the horror genre, it's only natural that the film would use something as cliche-ridden and commonplace as the humble zombie just to further get its point across.
Excuse me-"zombie redneck torture family", not "zombie'. They're two different species.
BUT! "redneck torture family" is an important distinction! The movie is at least in part a reaction to Torture Porn in horror and a voyeuristic that enjoys seeing things through the monster's eyes. What better monster than one who gets a "husband bulge" from "cutting the flesh"?
What's one of the things you don't want to do in a teenage slasher film? Drink alcohol! What happens to the controllers after their presumptive victory champagne? THEY DIE!
An alternative theory is that the ritual in that case was doomed to begin with, specifically because the "sacrifices" were children. None of them adequately fit the archetypes they needed to fulfill, and so the formula didn't work.
Except that would be following the American archetype, not the Japanese one.
Except that the Ancient Ones demand that the five archetypes be fulfilled. At first, it could be Fridge Horror by assuming that one of the 9-year-olds must be a whore. However, children are taught by someone but there wasn't a teacher in the classroom. The teacher must be the whore! It is possible to have an athlete, a class clown (fool), a scholar and (hopefully!) virgins in a group of 9-year-olds, so the archetypes would be fulfilled.
The archetypes for the American branch, as described by the American Director, need not conform with the Japanese archetypes, and vice versa. The archetypes for J-Horror are very different from those in American film — other than the kids having sex in a car in The Ring, NONE of the five archetypes described at the end of this film are found in The Ring or Ju-on or Chakushin Ari, for instance.
The Kyoto incident is the only incident shown on the monitors that takes place in daylight. Could the ghost girl have been set off early? Maybe she failed because the schoolgirls weren't her intended victims.
Of course it takes place in daylight. All the scenarios played out simultaneously, and it's day in Japan when it's the middle of the night where the Cabin is.
When do they state that the scenarios take place simultaneously? They all take place on the same night, true, but some had ended (in failure) by the time the monitor incidents were first shown. They might have been going for at least a few hours before they were shown, and had thus started before the Cabin scenario had begun.
The screw-ups didn't necessarily all happen during the final minutes of a scenario. Something as prosaic as the sacrifices-to-be actually listening to their respective Harbingers and going somewhere else could scuttle an operation, as could the wrong person dying first instead of last.
Why was there a "System Purge" button right there, unguarded, and so user-friendly that someone with no prior knowledge of the facility could activate it? Keep in mind, this film is all about deconstructing formulaic horror movie cliches (as well as a big middle finger to movie-goers who keep demanding that sort of thing), and what's two of the biggest cliches of a secret underground science lab? A big, red, shiny self-destruct button and nopreliminarysafety precautions.
The odds of anyone even getting to that level of the facility were extremely remote, much less pressing random buttons to do who knows what right before hitting the big red one.
None of which explains why the button exists in the 'real world' level of the story. Things do not exist on that level solely to evoke tropes—they exist towards the sole end of appeasing the Ancient Ones. Invoking tropes happens within the story because the ritual demands it—no other reason exists. That button having that function, being so easy to activate, being unguarded and more importantly, having the entire facility completely unprepared for its activation (why did no one build a door or some walls with the materials used for the cages?) was nothing more than a poorly thought out plot device.
The button was intended to be used in case it became necessary or desirable to get rid of the current set of monsters. Perhaps the Ancient Ones have occasionally supplied new sets. Or it was a last-ditch defence measure.
Perhaps the Controllers thought that they could press it to sacrifice their whole facility to the Ancient Ones in a particularly cliché-laden death.
If that were the case then they would have been appeased in the end. Then again, maybe they were, then got pissed again when the Director fell into their pit and broke the Fourth Wall?
It wasn't "unguarded", it was in a control room that would normally be occupied, in a part of the facility unauthorized personnel are never supposed to get to. The normal occupants were at the party. Under normal circumstances, they'd only open one cell at a time, with cages and handlers, so they wouldn't need extra-special security doors. Also, the company is dangerously arrogant, as we've seen several times before now. Most prisons have buttons to open entire cellblocks as needed.
The systems purge is probably meant for the cages. But Marty's tampering with the wiring of one, which had already caused problems, probably caused a glitch and opened all the cages instead of its original function.
Why do the monsters only attack humans and not each other? Lin says that the monsters were provided to the company by the Ancient Ones for the sacrifices. The monsters all only exist for one purpose: to kill human beings. They don't attack each other because they recognize each other as nonhuman.
Dana reacts oddly when she is told that she fits the role of The Virgin. Dana's reaction is because she knows that she is not a virgin. However, if you think about it, none of the other friends seem to fit their assigned roles at first. Jules is anything but stupid and Curt initially fits the role of The Scholar better than The Athlete. Of course, the organization has manipulated everyone's personalities to fit their roles in The Ritual. But what about Dana? Her personality doesn't seem to change much throughout the movie even with the manipulators in place. Dana fits the role of The Virgin solely because of the situation she is in. She recently got out of a bad relationship with a teacher and specifically states that she doesn't want the trip to be a "hook-up". She put herself in the role of The Virgin for that weekend.
The Director even says "We work with what we have."
Also Dana got labelled The Virgin because she was single. Jules got made The Whore because she had a boyfriend — therefore she was more likely to have sex while on the trip. The slutty girl in horror movies usually does have a guy she's been seeing, while if the Final Girl has a love interest, it's normally someone she just met.
The Harbinger wasn't calling about the kids. He was warning the crew about the end of the world. They ignored him, and that's why they were punished in the end, just like the kids they've sent to their deaths for years.
The Controllers even follow the phone call with a smug assertion that the victims are complicit in their deaths because they choose to ignore him!
The Harbinger specifically brings up the fact that "The Fool" was coherent enough to outsmart him, pointing out the clue to the flaw that would bring down the whole operation.
Another subtle hint that the Harbinger wasn't just talking about the kids? His name wasn't on the betting board. Why bet, if it doesn't matter what monster gets picked because the operation is doomed to fail?
Playing on the same idea, the five main Facility characters all die in ways that somewhat reflect what the five intended victims suffered:
Lin works for the Chem department, which screwed up on drugging Marty's weed and thus invited disaster. Like Jules, who got screwed and invited disaster upon herself, Lin is grappled and dragged to her death by the Kraken, same as the Whore was snared and dragged by the bear trap.
Truman is the most physically-fit of the named Facility characters. He dies by his own hand when he pulls a grenade to take the Scarecrow Folk with him, same as Curt the Athlete dies by his own hand, in trying to save the day by jumping his bike over the canyon.
Hadley is the comic relief of the Control staff, drinks on the job, backtalks the Harbinger, slips into philosophical asides interspersed with goofiness, and even hangs a lampshade with his last words. He's mauled by the Merman in a fountain of blood, much as Marty gets dragged off-camera by Judah Buckner with a splash of gore; all that sets Hadley apart from the Fool is that he doesn't survive that encounter.
Sitterson is the knowledgeable, nerdy professional of Control. Like his fellow glasses-wearer, Holden the Scholar, he's fatally impaled by a rusty blade in the hands of an attacker he didn't even realize was there.
The Director, the likely Final Girl of the Facility staff, gets attacked by a werewolf and Patience, then plummets to her presumed death in the Ancient Ones' pit. Dana likewise gets were-chomped and menaced by the undead girl, and presumably dies when the Ancient One's arm emerges from said pit: small wonder that many fans suspect the Director is a surviving Virgin as well.
Note, also, that the sequence of these five deaths is just as wrong as it is for the intended sacrifices. Lin dies after Truman and Hadley, whereas the Whore-figure is supposed to die first. The co-eds' death order is messed up at the closing end, with the Virgin failing to out-live the Fool; the Facility staff's deaths mess up the sequence at its beginning.
Amongst the monsters are special infected from Left 4 Dead. Now what does the director do in that game again?
Just before they meet the Harbinger, Jules remarks that the road they're driving on doesn't show up on her GPS. The five assume it's because it's so obscure, but it's likely that the facility's government backers deliberately keep its location off the system.
If the facility controls its "stable" with gas, why didn't Sitterson order that such gas be released into the elevator which Marty and Dana rode down in, so Marty could be captured and killed without resistance? Because that particular elevator was also the Buckners' isolation cube, and whatever measures the handlers might've used to control them would be designed to work on the undead, not on live humans.
Why was Marty the only one who twigged that something was Very Not Right with the whole situation? This is partially explained by the fact that the controllers weren't able to get to the stash of weed he had on him, but think of it this way: One of the side effects of pot use is paranoia.
And also we've seen the sacrifices be controlled by gas (When Curt changed his mind about separating, pheromones...) and he's high.
At first it's odd that a bunch of different archetypes would go on a trip together, but then it's clear that Curt ties them all together. He's close friends with Marty, who knows him from sociology, and knows Holden through sports (the others are just meeting him as he's a transfer student, or at least Dana is). Curt's dating Jules, who is either best friends with or lives with Dana, and Curt's friendship with Marty explains why he knows the girls well.
Not only did the Controllers radically alter the students' personalities, in doing so they actively took away any skills the heroes could use against them. Jules was the Team Mom, responsible and pragmatic. She's turned into The Ditz, taking away an intellectual element. Similarly, Curt goes from a Genius Bruiser who Minored In Ass Kicking into just a Jerk JockDumb Muscle; most evident when his natural personality tells them to stick together, but the Controllers make him change his mind. Holden is the most physically capable of the group and a full badass, so the Controllers turn him into a Hollywood Nerd to prevent him from fighting back. Dana, the artist who has flings with professors and has an unpredictable nature is turned into The Virgin to make her demure and not assertive. And Marty, who also Minored in Ass-Kicking with Curt and is just as smart, was intended to have his drug use altered. But since his drugs were untouched, he's more cautious and able to fight back. He refuses to drink, instead of turning into a hedonist. The Controllers weren't just "working with what [they] have" to fit the ritual, they were handicapping the students.
Even some of the betting board choices have Fridgy elements, if you consider which monsters are matched with which departments:
Bio Med chose "Alien Beast", which would certainly seem scary to medical personnel if it's an Alien reference: they'd know exactly what the consequences of Face Full of Alien Wing-Wong and Chestburster would be to a vulnerable human body.
The Wranglers chose "Angry Molesting Tree", which is one of the biggest monsters and certainly one of the most difficult to try to wrangle back into its cube, more so in that gas probably wouldn't work very fast against a plant.
Story bets on "Deadites". Of course they do: while the sacrifices' individual actions aren't scripted, the initial sequence of events that befall them reads like a plot summary of The Evil Dead (1981).
The Kitchen Staff chose "Dolls". Both killers and victims in The Strangers mostly use kitchen knives, weapons too mundane for most of the other board-listed monsters to bother with.
Research And Development bet on "Huron". Whereas most of the monsters seem to have been dreamed up from scratch by the writers, the Huron probably required at least some actual research on colonial-era Native Americans, if only to avert inappropriate use of Braids, Beads and Buckskins in his costume design. Or just to find him in the first place.
Demolition bets on "Mutants", which are usually depicted as arising after the demolition of human civilization after World War III.
Psychology placed its bets on the "Mummy". As they're frequently depicted as slow-moving yet cunning, films featuring mummies often play out more like psychological thrillers than straight-up horror flicks.
Maintenance bet on the "Zombie Redneck Torture Family". The cabin is strongly implied to have been the Buckners' family home in the first place, so out of all the monsters, they'd be the least likely ones to trash the interior and leave a huge mess for the Maintenance staff to clean up. Hence, they always favor the Buckners.
The Chem Department bets on (conventional Romero-style) "Zombies". Given that Chem are the ones who screwed the pooch, why wouldn't they also have bet on what are probably the least intelligent monsters on the board?
Dana has the typical Final GirlMade of Iron... because in addition to drugging the sacrifices to make their personalities fit the molds, they gave Dana something to make her more physically resilient so she'd be a "proper" Final Girl.
She also might have been chosen with this in mind, aside from getting drugged.
The Latin phrases in Patience's diary really don't mean what Holden claims they do. This makes sense on no less than three different levels: 1) on the "Show Within a Show" level of the Zombie Redneck Torture Family encounter, you wouldn't expect Patience or whichever backwoods sorcerer-wannabe who wrote the spell to know much Latin; 2) on the Organization-Scripted-Sacrifices level, you'd expect any such incantation to be oversimplified intentionally, so that students who didn't know more than the rudiments of Latin and were operating under the influence of drugs could still puzzle out enough of it to spook themselves; and 3) on a Joss-Whedon-Plays-With-Horror-Tropes level, it's yet another cliche for filmmakers to throw a bit of gratuitous Latin into magic spells without actually having a clue (or giving a damn) if it's right.
The Harbinger refers to Jules as "that whore." That's because he knows that's the role she is expected to play, since he works for the Facility.
In the shot revealing the many, many cubes containing the Facility's "stable", the ones containing the Dragonbat, the Robot, the Giant Snake and the (non-redneck) Zombies can all be seen clustered around the cube that Dana and Marty are inside. All four of these monsters, plus the Werewolf that was initially adjacent to Marty and Dana's cube, will be part of the first wave of the Purge, because they're nearest to a cube that's already bound for the exit.
Meta-example: In the commentary, Joss Whedon mentions that when they wrote the script for the ending, they simply put a single line in for all the various horror movie kills that would be shown on close-circuit: "There's chaos on every screen." Only much later did they realise that not only would they have to shoot all this chaos, but those five words would eat up a very substantial portion of their budget.