* AccidentalAesop: For ''Paranormal Activity 2'': [[spoiler:Never foist your problems on your in-laws.]]
* AlternativeCharacterInterpretation: The demon in the first one. Despite what is revealed about it in the later installments, more than one watcher thought to themselves that they would probably kill Micah too, if they were demons and he stayed in the place they lived all day and yelled at them for moving stuff or doing anything aside from sitting quietly and never moving or making any noise.
* CompleteMonster: While you could argue that the demon is just following its natural [[spoiler: Lois the grandmother of Katie and Kristi sold her granddaughters to a demon just for wealth and is responsible for the deaths of her daughter and Dennis]]
* CowboyBebopAtHisComputer: The Netflix description of ''3'' says it is a sequel instead of a ''prequel'' to the series, and that ''4'' takes place 5 years after ''3'' instead of ''2''.
* EnsembleDarkhorse: Dennis of ''3'', probably for being more competent and likable than Micah and Dan. Also, Ben from [=PA4=].
** Arturo from ''The Marked Ones'' is getting some love from fans for [[spoiler: using a shotgun to kill some witches.]]
* FirstInstallmentWins: Compare the reviews of the first film to its latter sequels.
* FunnyAneurysmMoment: Katie's "I'm not really evil, but I can be evil" comment at the start of ''2''.
** On a similar note, in ''3'', when Katie is beating the hell out of a piņata at her birthday party, Dennis jokingly comments that "(Katie's) a little monster".
* HellIsThatNoise: The ambient rumbling noise that almost always accompanies the demon.
** This is a large part of what the demon does in the first film. It spends most of the film just fucking around with Katie and Micah until the last 20 minutes or so when the demon decides to go for full-blown NightmareFuel.
** ''AAAAAAHHHHHHHGGGG! MICAH!! '''MICAAAAAHHHHHH!! AAAAAAUUUUUUGGGG--'''''
** Some viewers found [[spoiler: [[NothingIsScarier the cut-off end of the scream and the span of time before the final scene scarier than the scream itself.]] ]]
** In an early jump scene, the protagonists listen carefully after Katie thinks she hears something. After a few moments of dead silence, there is what can only be described as an extended scream/howl, followed by a massive ''thump''. [[NightmareFuel Bricks were duly shat]].
** The sequel manages to do this with a ''children's toy.''
** An infamous scene from ''2'': [[spoiler: during the day in the second movie you get about a minute of silence before everything in the kitchen flings open and falls.]]
** Shortly after the above-mentioned kitchen scene, there's the piercingly loud whistle of the kettle.
** Also from ''2'': Hunter's screams of terror.
** Any time the demon is heard making some kind of vocal noise, like growling, roaring or breathing.
* HypeBacklash: Much like ''TheBlairWitchProject'' before it, getting so many reviews dubbing it one of the scariest movies of all time ensures that some people will watch it and end up unimpressed.
* ItsTheSameNowItSucks: An already common criticism of ''Paranormal Activity 2'' and the following sequels is that it too frequently uses familiar scenes from the first movie.
* JerkassWoobie: Micah; arguably Dan as well. Yes, they are [[AssholeVictim Asshole Victims]] for a lot of viewers, but eventually Micah all but abandons his {{Jerkass}} and ItsAllAboutMe attitude and shows that he really does care about Katie. In the case of Dan, while his act of [[spoiler:transferring the demon to Katie]] is seen by some as a MoralEventHorizon, he does it out of his desperation to protect his wife and son. [[spoiler:Unfortunately for him and his family, it doesn't work.]]
* Narm: While the footage of Robbie climbing into bed with Alex is supposed to be creepy, many people found it more adorable.
* NightmareRetardant: Although the movie is quite terrifying, close examination of its premise actually leaves quite a bit of hope for the viewer: Any evidence of [[spoiler:demonic possession]] in your family? No? You're free, go out and enjoy life! [[NightmareFuel Not that it helps much when you're trying to sleep, of course.]]
** The fourth movie coming up kindly removes this-- while the hauntings center on [[CreepyChild Robbie]], the targets are Alex and her family, his new neighbors who didn't know any better.
* ParanoiaFuel: The movies are basically engineered to play on fears of odd noises in your house at night.
* UncannyValley: The first time [[spoiler:Katie]] shows up in ''Paranormal Activity 4'', she's completely in her [[spoiler:demon-controlled blank affect mode]] for ''just'' long enough before acting normal that it becomes this.
* TheScrappy: [[AssholeVictim Micah and Daniel]]
* TheWoobie: Ali in ''2''. First her parents don't believe her when scary things begin to happen, [[spoiler: one day her stepmother wakes up acting like a cross between a wolf and a serial killer. Then, oh, things are looking up! No horror for three weeks! Until you come home to find your family brutally murdered.]]
** Any heroic dog in a horror movie is almost contractually obligated to be the most sympathetic character in the movie. Hence, Abbey. [[spoiler: But thankfully she lived.]]
** Dennis in the third film. [[spoiler: He did cared for his stepdaughters and wife and wanted to find out about the demon and save his family. Yet his wife dies in front of him and is killed by his mother-in-law. All while trying to save his stepdaughters.]]
** Kristi. The events of ''2'' and ''3'' would have been prevented had they just listened to her. Also, Dan (in the second) and Katie (in the third) are mean to her for little reason.
** Katie. Imagine being haunted constantly by a demon [[spoiler: and spending the rest of your life possessed by it, where you have killed several people including your own sister with no control. '''AT ALL''']]
** Alex from P4. It wasn't her fault that she and her family [[spoiler: adopted the one boy the demon was after.]]