History YMMV / Signs

** The confrontation with an Alien at the end has a flashback suddenly occur where Graham listens to his wife, in her dying words, list off things to do with his family, where she notes she was just taking a walk before dinner... Graham noting "she loved walks." Already silly itself, she then makes several requests, seemingly having enough life in her to do so, all topped off with her last one where she asks Graham to tell Merill to "swing away," which apparently means for Merill to grab a baseball bat and "swing away" at the Alien in this particular moment. Yes, seriously just beating the shit out of the monster is the way to go and our protagonist had to recall a very specific line from his dying wife to initiate exactly that. And that's on top of the Aliens' weakness of water being shown in full, too!

** Yet another interpretation says that they aren't actually aliens, but demons. This makes sense if you think about it. Their behavior could come across as like that of a bunch of supernatural tricksters, always hiding out of plain sight except when they want to be seen and their weakness to water could be because not for biological reasons, but again, supernatural ones, as the water could be considered holy. Remember the little girl who is described as like an alien, and how she always drinks water but never finishes, leaving the glasses everywhere?

** The shot of Merrill and the kids wearing tinfoil hats has also been frequently used to mock conspiracy theories.
* MoralEventHorizon: The wounded alien attacks the house because he wants revenge on Graham for cutting off his fingers. All right, that's understandable... wait, he's going to get revenge on Graham by attacking, with murderous intent, ''Graham's son?'' Dick move.
* {{Narm}}: The decision to have the aliens be weak to ''water'' is widely considered to be a mind-numbingly stupid creative decision that makes the finale unintentionally ''hilarious''. When Graham mentions the water theory, his son even says "that sounds made up." And it's not that he doesn't believe him, it's more like there is NO WAY the aliens could be that stupid.

** The famous Brazilian birthday party scene is considered one of the scariest and memorable moments of the movie. However, for Brazilian viewers it can be unintentionally hilarious because: the man who recorded's name is Romero Valadarez (a Spanish name rather than a Brazilian-Portuguese one), one of woman speaks in a Carioca (Rio de Janeiro) accent rather than the local "Gaúcho" raccent, a scared Graham screams "Vamonos" (''Spanish'') to the kids in the television, one of the kids speaks in Portugese from ''Portugal'' and then for no reason screams in English "IT'S BEHIND". The Brazilian dub of the movie straight-up dubbed over the boy. On the other hand, the tension of the scene is still praised, and the people from Passo Fundo love that their mostly unknown city recieved such attention.

** The famous Brazilian birthday party scene is considered one of the scariest and memorable moments of the movie. However, for Brazilian viewers it can be unintentionally hilarious because: the man who recorded's name is Romero Valadarez (a Spanish name rather than a Brazilian-Portuguese one), one of woman speaks in a Carioca (Rio de Janeiro) accent rather than the local "Gaúcho" raccent, a scared Graham screams "Vamonos" (''Spanish'') to the kids in the television, one of the kids speaks in Portugese from ''Portugal'' and then for no reason screams in English "IS BEHIND". On the other hand, the tension of the scene is still praised, and the people from Passo Fundo love that their mostly unknown city recieved such attention.

** Another possibility is that the aliens don't have water on their homeworld and didn't know that it would harm to them

* AmbiguousDisorder: Bo's extremely specific aversion to finishing glasses of tap water for fear of it being contaminated could be read as a symptom of OCD. Some viewers have also interpreted her emotional flatness and strange behavior as signs of autism.

** "Because they (the Aliens) seem to have trouble with pantry doors."

** Ray Reedy, the guilt-ridden driver who killed Mrs. Hess, gets an emotional scene apologizing to Graham before revealing he has an alien trapped in his pantry. Ray does appear in two other scenes, but only briefly and without speaking. He's also played by M. Night Shyamalan himself.

** The big twist shouldn't have been that the aliens were vulnerable to water, they should've been vulnerable to ''soda''. Not only is this slightly more believable - the aliens are allergic to the carbonation/sugar/food dye/etc. - but it ties neatly into a larger meta-joke based on what the old man was ranting about earlier in the film; he thought the "alien invasion" was just a hoax to sell soda commercials, and in the end, the world was saved by soda. The whole movie could've been a "soda commercial."

* IdiotPlot: As mentioned... everywhere, the aliens invading a planet that's covered in 70% water without wearing so much as ''shoes'' when water is completely toxic to them, don't have weapons, and are easily captured, outwitted, or outsmarted by random people.

* AlternativeCharacterInterpretation: The aliens. Their complete lack of armor and weapons is usually cited simply as incompetence, but some more serious hypotheses have been put forward. The two most prominent are that the aliens [[HumansAreTheRealMonsters were actually peaceful, and only began attacking humans after the humans were aggressive towards them]], or that they were actually [[DoingInTheScientist demons defeated by holy water]].
** An alternate take is that we're not supposed to understand why. The movie is attempting to convey an alien invasion not from a gutsy action hero's perspective who blows stuff up and saves the day, but from a normal family who's just trying to hunker down and live through it. We don't understand why the aliens do what they do the way they do because said family almost certainly wouldn't have any clue.

** A less serious interpretation is that this was the aliens' version of a frathouse prank, akin to forcing a pledge to try to, say, get honey from a beehive naked or something.
*** Being even less serious, these are the extraterrestrial equivalent of the cast of ''Series/{{Jackass}}.''

* AllThereIsToKnowAboutTheCryingGame: These days, the movie is widely known as "The one about the aliens who can be killed by water", largely due to this PlotTwist being thoroughly mocked by its detractors. It's easy to forget that (apart from the twist) it actually got quite a bit of acclaim in its day for its unconventional take on the AlienInvasion story, and for its unique mix of science-fiction, horror, drama, and spirituality.

* ItWasHisSled: Even those who have not seen the movie are often aware of the twist. Shyamalan movies in general are vulnerable to this.

* OlderThanTheyThink: The death of Graham's wife is taken beat for beat from an old {{Glurge}} story circulated on the internet.

* {{Narm}}: The movie would actually be a pretty good thriller if it wasn't for the mind-numbingly stupid decision to have the aliens be weak to ''water''. When Graham mentions the water theory, his son says "that sounds made up." And it's not that he doesn't believe him, it's more like there is NO WAY the aliens could be that stupid.

* {{Narm}}: The movie would actually be a pretty good thriller if it wasn't for the mind-numbingly stupid decision to have the aliens be weak to ''water''.

* EndingAversion: In contrast to the more generally ill-received films that M. Night Shyamalan would produce after this film up until his CareerResurrection in the mid-2010s, this one's mostly seen as a film that has some good atmosphere and performances, but is let down by a silly and contrived ending.

** "Because they *the Aliens* seem to have trouble with pantry doors."

* CriticalResearchFailure: Despite Shyamalan being from Philadelphia, his version of Bucks County is hilariously wrong... to the point that Bucks residents didn't even ''realize'' it was set in their county initially, let alone the ''county seat.''
** The uniforms the police wear don't look anything like what any officers in Bucks County wear or have ever worn - Sheriffs, deputies, state patrolmen, local police, or anything.
*** To wit: Officers in Bucks all wear blue uniforms, not brown. The jackets they wear are blue windbreakers, not brown with fur trim. They also don't wear wide-brimmed hats; they wear standard police hats, if any hats at all (most don't). Ultimately, the police uniforms seen in the movie look like California outfits, rather than Pennsylvania uniforms.
** There are no large farms at all within the vicinity of Doylestown, as the entire area is much too hilly for proper farming, and by now much too developed.
** There are also no large natural bodies of water within ''miles'' of Doylestown - where that lake came from is anyone's guess.
** While there ''are'' a ludicrous number of trees in Bucks County and Doylestown especially, which give a little privacy, it's also so densely populated that it's literally impossible for a farm to be secluded - there would have been at ''least'' two dozen houses within short walking distance and probably ''line of sight'' of the farmhouse.
** The setting as a whole looks nothing like Bucks County except maybe the northern-most areas; it actually bears more of a striking resemblance to the Poconos about a half-hour farther north.

** Still another interpretation is that [[AllJustADream the alien invasion is really a dream Graham is having]] as he mentally wrestles with his loss of faith after his wife dies. This would seemingly explain odd scenes like the illustration in Morgan's book that shows people who look like Graham and his children lying dead outside a burning house, the strange conversation with the army recruiter which sounds like something from a Creator/DavidLynch film, and the alien's [[WeaksauceWeakness weaknesses]] like water and the inability to open doors. It's all dream logic at work.

** "Because they *the Aliens* seem to have trouble with pantry doors." Yes. Apparently, the main threat of the movie aren't capable of getting through "DOORS."

* AlternativeCharacterInterpretation: The aliens. Their complete lack of armor and weapons is usually cited simply as an example of WhatAnIdiot, but some more serious hypotheses have been put forward. The two most prominent are that the aliens [[HumansAreTheRealMonsters were actually peaceful, and only began attacking humans after the humans were aggressive towards them]], or that they were actually [[DoingInTheScientist demons defeated by holy water]].

* WhatAnIdiot: The aliens, as explained under FridgeLogic. What were aliens vulnerable to water thinking in invading Earth?

* MoralEventHorizon: The alien that stays behind does so because he wants revenge on Graham for cutting off his fingers. All right, that's understandable... wait, he's going to get revenge on Graham by attacking, with murderous intent, ''Graham's son?'' Dick move.
** It is stated by Merrill that the aliens left their wounded behind so the alien at the end most likely didn't stay of its own accord.

** Ray Reedy, the guilt-ridden driver who killed Mrs. Hess, gets an emotional scene apologizing to Graham before revealing he has an alien trapped in his pantry. Ray does appear in two other scenes, but only briefly and without speaking.