Fear is a part of existence, and in its true form, is not pleasant to experience. Scared people are prone to knee-jerk decisions, which is understandable. However, not all fear experiences are created equal. Some fears are immediate, apparent, and deep... And others are based around vague possibilities, whispers, rumors, stuff that could happen with variable or unknown odds. It is a low, background fear that lurks in the back of your mind, the classic paranoia. And sometimes, people just can't live with it, and do something to assuage it. When it actually has some merit, this is Properly Paranoid. Many times, it doesn't. It is also always an overreaction. Not that that matters. All that matters to the sufferer is to assuage that fear. This is not The Paranoiac. That trope's examples are demonstrated to be paranoid all the time, about everything, so they're afraid of everything. And often, such behavior will result in purely defensive reactions (going off the grid, tinfoil hats, etc). This trope is about when people are unable to live with the mild fear of certain possibilities and end up making decisions that not only affect other people negatively, but very often end up causing the exact situation they feared to come to pass. This is especially prevalent if the being who does it should be smart enough to see the very clear possible backfires and downsides (or has direct past experience of these kind of actions not working), but does it ANYWAY. The end result is never good. In fact, it almost always ends in Self-Fulfilling Prophecy. Nice Job Fixing It, Villain!, Nice Job Breaking It, Herod!, and all the tropes in that vein (they're also incredibly vulnerable to Paranoia Gambits and are often what said gambits aim to achieve, though using one might end up backfiring in turn because of the severe overreaction that can occur). All because they can't live with their fear, however mild and background and running on long odds it may be. Can also lead to Bullying a Dragon, and the consequences of THAT trope as well.
- While not completely unjustified, the plots regarding many General Rippers trying to get rid of Superman (for example, New Krypton). This trope extended to the animated continuity of the DC Universe as well; see below.
- The comic book version of Red (though not the movie, which is very different) has this drive the whole plot. Paul Moses is a retired CIA agent who has done many, many bad things for the sake of his country, but is now an old man content to quietly while away his final years in isolation. Then the CIA gets a new director, who learns of Moses' existence and deeds, and completely freaks out over them, and more specifically, what could happen if anyone found out. Never mind Moses is tucked away counting his days until death; the fear of the possibility is too much and said director orders Moses' assassination. And things go downhill from there...
- End of Days has this as a small sub-plot: it's bad enough that Arnold has to protect the devil's chosen bride against Satan himself and a New York where every third person is apparently a devil worshipper, but he also has to deal with a subset of priests who want to just kill the devil's bride to remove any chance he can bring about the end of the world with her (even if it's not a permanent measure—they simply don't care as long as it doesn't happens within their lifetimes). Even another priest calls out the wrong-headed nature of this reaction.
Father Kovak: You can't prevent evil by doing evil!
- Doctor Strangelove: The original General Ripper decides to nuke all of Russia because of an alleged Russian plot to make Americans unable to have sex. In an era where Communist Russia literally had dastardly plans going on, he still decides to jump to the most improbable theory possible (fluoride in water added by a Communist conspiracy) for his sexual inadequacy instead of more probable reasons like stupid people manning the aqueduct (if the fluoride theory is true) or his own bodily health (too much drinking and smoking, or maybe him being too old to find women attractive anymore). In essence, Ripper decides to start World War III because he can't stand the idea that he has become impotent solely on his own choices.
- Hercules has King Eurystheus. In this version of the story, Hercules didn't kill his family due to Hera driving him mad: instead Eurystheus drugged him and had a pack of wolves kill his family while making Hercules think he had done it. Why? Because Hercules was lauded as a great hero and the son of Zeus, and he believed that eventually the people would call for him to be king. He figured killing Hercules would make him a martyr, so he decided to ruin his life and name instead. What REALLY drives this home is that Hercules had zero interest in being king and says so outright (that he 'wanted nothing'); Eurystheus, clearly projecting himself onto the hero, counters with this bit of Insane Troll Logic.
- King Eurystheus: Precisely! Your sin, Hercules, was that you had no ambition! I can deal with an ambitious man! He can be bought! But a man who wants nothing has no price!
- Enemy of the State: All of the drama that the evil NSA agents pile onto Philadelphia attorney Robert Dean is because their leader, NSA official Thomas Reynolds, sees Dean's history of helping civil unions and connections with parties that dislike the Agency and he immediately assumes that, when Dean was accidentally handed the video that showcases Reynolds orchestrating the murder of a U.S. Congressman, it was an actual deliberate action to get him arrested—that Dean knuckles down and refuses to talk when Reynolds' goons arrive to his house and get too pushy with their fake interrogation just fuels this assumption. Dean, on his end, only starts taking steps once the NSA has nearly destroyed his life and are actively pursuing him on the streets with full intent to kill him.
- Harry Potter: As the letters from Hogwarts grow ever more numerous, Uncle Vernon takes increasingly-strange measures, such as moving away from the house to a tiny island in the middle of nowhere and buying a gun. It could have ended very badly had Hagrid not taken the gun and tied it into a knot.
- There's also the Running Gag of Harry constantly believing that Severus Snape is part of any plot that is occurring on Hogwarts is pretty much this Trope in action... and even when he was, he was Good All Along. Though Snape being an asshole to Harry almost all of the time because of old grudges regarding his father didn't help.
- The Light Fantastic has the wizards summon Death. One of them, not liking the way Death was looking at him (ie, Death is coming for him), proceeds to build a box with every enchantment, ward and protective spell he can think of and climbs inside, certain he's secure. The last thing he hears is a voice next to his ear saying "DARK IN HERE, ISN'T IT?". In building his box, he did not stop to consider adding airholes.
- Amy Tan's characters often find themselves in this situation. When your mother is constantly warning you of potential disasters, you might lose your sense of agency. Several of her characters have to overcome this feeling, as they've stayed in bad situations because to take action is to take risk. In a couple of cases the mother even helps them on this.
- A Point Horror book, The Hitchhiker, has this happen at the end. After plot twists reveal the titular hitchhiker is not the villain, the female main characters were involved in a hit and run, and the son of said victim of said fatal hit and run decided the best solution was to track down the girls, kidnap them, and feed them to a convenient lake of piranhas as revenge, the would-be avenger ends up eaten in his piranha pool. At this point, one of the girls (seemingly the only survivor at the time) decides that she has to get rid of all the witnesses to her crime and retrieves the now-dead avenger's gun to make the hitchhiker either jump into the pool or be shot. The other girl revealing herself to NOT be dead results in said paranoid girl ending up eaten in the piranha pool as well, when all she had to do was walk away and she might have not even been charged with her crime considering the now-extreme extenuating circumstances around it.
- Tom Waits' poem "What's He Building In There?" is the musings of a man who believes a neighbor is up to no good because of little facts like not waving as he passes by and escalating to weird things (which the narrator may be making up) like swearing he heard someone moaning inside of the neighbor's house. The poem ends with "we have a right to know", implying that the narrator is going to go and barge into the neighbor's house.
- Doctor Who has the Time Lords, who might be the grand champions of this trope, with how often they've done stupid things and screwed themselves over out of fear of certain possibilities, all of which are always tied up with their errant child slash grand champion, The Doctor. What really drives it home is despite how old, advanced, and wise they are, and how often the Doctor has pulled their fat out of the fire, they keep finding reasons to piss him off. The Series 9 penultimate episode Heaven Sent. where the Time Lords ( fresh off escaping back into proper reality, their survival and return only possible because of the decisions of the Doctor, at that), afraid of a prophecy of a being called 'The Hybrid', and believing the Doctor knows what it is, proceed to (instead of say, contacting the Doctor and asking him) put a scenario into action that not only leads to the inadvertent death of his companion Clara, but sticks the Doctor into a pocket reality trap that he can only escape if he confesses what the Hybrid is, or he can die and take the secret to the grave with him. The Doctor refuses, believing the knowledge is far too dangerous to be shared, and instead takes a third option by using the time-resetting nature of the trap to spend FOUR BILLION YEARS breaking out of it., and when he gets out he's PISSED. How pissed? Bring down the government, willing to break the universe to undo what the Time Lords did, pissed.
- In The Twilight Zone (1959) episode "The Mirror", a revolutionary-turned-dictator inherits a mirror from his predecessor, which the man says will show a person his enemies. The new dictator becomes paranoid as he sees his friends in the mirror and kills them off. Finally, after having thrown the entire country into disarray with his paranoia, he sees himself in the mirror. Two people walk into the room to find him dead on the floor.
The last assassin. And they never learn. They never seem to learn!
- Throughout the second season of Tyrant, Jamal makes increasingly poor decisions in his efforts to fight off an invasion by the Army of the Caliphate, largely because he's grown so paranoid that whenever one of his military advisers demonstrates a successful strategy, Jamal believes that that adviser might end up plotting against him.
- Orphan Black
- Alison strongly suspected her neighbor Aynsley is spying on her for the Dyad Institute. She went out of her way to antagonize Aynsley in retaliation, to the point of making herself a social outcast. It's only after letting Aynsley die in a preventable freak accident that Alison finds out she was actually innocent, if rather nosy. She becomes crushed by guilt and quickly ends up becoming an alcoholic (though she gets better).
- Zig-zagged in the case of her husband Donnie, whom she also thought might be a spy. He was, but didn't realize it because he'd been tricked into thinking it was a sociology experiment. So when she tortured him for information, he genuinely had no idea what she was talking about. Alison figured he was innocent until she found out that he'd been in contact with Dr. Leekie, a scientist at Dyad. When she confronts him, Donnie admits to working for Leekie, but is horrified to learn what was really going on.
- The plot of the first season of Once Upon a Time is driven by Regina's fear that her adopted son's biological mother, Emma, will break the curse and try to take him away from her. Emma initially didn't believe in the curse and had no intention of trying to regain custody, but it was Regina's paranoid and over-the-top behavior that caused Emma to change her mind.
- Greek Mythology is full of kings whose sons/grandsons were prophesied to dethrone them, and reacted by sending the baby to be killed or walling up their daughters. In every case, they weren't paranoid enough: either the servants sent to do the deed couldn't go through or the girl was rescued by a god, ensuring the child would be a nigh-unkillable demigod.
- Warhammer 40,000: The Inquisition lives in between this Trope and Properly Paranoid, Depending on the Writer: any time they so much as suspect Xenos or Chaos taint, out comes the Kill 'em All measures like Exterminatus. They are willing to perform this even if it means going to war against other branches of the Imperium, such as the Space Marines (a pretty famous fluff piece of the Space Wolves involves the Marines fighting an Inquisitorial task force that had been sent to kill all of the Guard soldiers (and evacuating civilians) on a certain planet just because they were fighting against Chaos, a mission they were willing to fulfill even after the Marines told them that none of the other humans were tainted and assured them that they were willing to fight to protect said citizens). To be fair to the Inquisition, considering the consequences of being wrong and/or missing something and how rapidly it can snowball, you can't blame them for having very twitchy trigger fingers. Of course, many take this as an excuse to leave the Moral Event Horizon long in the distance...
- Teyrn Loghain Mac Tir, the Bad of The Good, the Bad, and the Evil ensemble in Dragon Age: Origins, is excessively paranoid of all things Orlesian, having spent his youth fighting a guerilla war against the Orlesian occupation of Ferelden. Unfortunately, this manifests itself in his utter distrust of the Orlesian chapter of the Grey Wardens—a truly Impartial Purpose-Driven Faction—as well, leaving Ferelden (which, for historical reasons, barely has any Warden presence of its own) defenseless when the Darkspawn attack.
- Characters in Crusader Kings with the "Paranoid" trait have a tendency to see plots against themselves and their loved ones everywhere, or suspect that they're not the father of their wife's child. They're right some of the time but most of the time they're wrong: a good rule of thumb for players is that if your spymaster didn't tell you about the plot, your character is imagining things.
- Said trait returns in Crusader Kings II: any character that has it lowers his diplomacy, but increases his intrigue. In THIS case, however, however, one of the most useful traits in the game, since it also makes your character pretty much invincible against plots, which is quite useful in a world full of Ax-Crazy nobles.
- Like the comics, this trope crops up in the DC Cartoons.
- General Newcastle on Superman: The Animated Series believes that Superman is evil just because he's an alien and nothing else. When he becomes a founding member of CADMUS and eventually retires, he still keeps a pistol with Kryptonite-laced bullets next to him at all times because he thinks Superman will eventually come and try to kill him (and never seems to consider that CADMUS might do it because He Knows Too Much...)
- The CADMUS plot line on Justice League Unlimited is also eventually revealed to be this: people who were concerned about super humans going evil jumping the gun straight into Fantastic Racism, fascist tactics, inhuman weapon experiments and attempted genocide-to not mention other war crimes like launching a Kryptonite-laced nuke right at a still-evacuating island, thinking of all the innocent people as "acceptable casualties" as long as Superman (and Doomsday) died. The CADMUS example might possibly skirt the line between this and Properly Paranoid. On the one hand, the series goes to great lengths to imply that it is reasonable to be afraid of what uncontrolled superhumans could do, to the point of introducing an alternate universe League that went rogue just to prove the point. However, it is also frequently pointed out that CADMUS may have partially started the problem by doing things like creating Doomsday, attempting to kill or discredit the League, and attempting to create their own army of superhuman mooks — some of whom were only children — all before the League had done much to them.
- Avatar: The Last Airbender: As Azula's paranoia gets worse, she starts seeing traitors everywhere and exiles bodyguards and servants left and right. In the end, she is of course betrayed by the people she thought she'd best terrified into loyalty.
- Plenty of historical dictators were this. A random example is Josef Stalin, whose purges to protect himself crippled the Soviet Union's military, yet led him to trust Adolf Hitler on the basis of "I see myself in him and I would never do that", in the face of loads of evidence to the contrary. Another is Pol Pot, who was so afraid of 'intellectuals' 'contaminating' his dictatorship that he went as far as executing people solely because they wore glasses.
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