"The difference between genius and stupidity is that genius has its limits."
All too often, a plot thread depends on one or more characters doing something really stupid. They don't have any chance of doing the smart thing, because then the plot-driving conflicts wouldn't happen.
Even if the stupidity is an organic outgrowth of prior characterization, that doesn't necessarily make it contrivance-free. As addressed in The Movie and lampshaded in the "Homer's Enemy" episode of The Simpsons, the continued tolerance of Homer by his friends, his family, and his employer — indeed, his very survival — is simply unbelievable at this point. Then again, Rule of Funny.
Contrived stupidity commonly causes things like the collapse of A Simple Plan in a Sitcom or the effectiveness of Schmuck Bait in Slasher Movies. It is often accompanied by the meta-stupidity of the other characters' ignorance of Hanlon's Razor. It is vulnerable to Fridge Logic; however, do remember that Tropes Are Not Bad.
On the other hand, it should be noted that many Contrived Stupidity Tropes are also Truth in Television to some extent and have several Real Life examples.
Contrast with Intelligence Tropes. Compare Stupidity Tropes.
Tropes:
- Abilene Paradox: Everyone agrees to do something no one wants under the assumption that everyone else does.
- Achievements in Ignorance: A character is able to do something solely because they didn't know the action was not possible.
- Alcohol-Induced Idiocy: A character becomes stupid after getting drunk.
- Apathetic Citizens: The citizens can't be bothered to care when something bad is happening.
- Bond Villain Stupidity: The villain tells the captured hero their plan while leaving them in a very slow death trap, certain that there's no harm in spilling the beans if the hero is going to die.
- Bullying a Dragon: Someone picks on a being who could easily kill them (or at least cause them great harm) in retaliation.
- But Thou Must!: Refusing to do something in a video game will only result in you being forced to make the decision anyway.
- Butt-Dialing Mordor
- Callousness Towards Emergency: Someone rudely brushes off a person in real danger needing their help as unimportant.
- Chained to a Bed: Someone agrees to be tied to the bed as part of foreplay, only for their partner to take advantage of their trust by robbing the tied-up person and leaving them there.
- Closed Circle: The characters cannot leave their area or get help until the very end.
- "Could Have Avoided This!" Plot: The end of the story has the characters acknowledge that it would've been simpler if they had gone with a different solution to the problem or if they had explained things better to one another.
- Clutching Hand Trap
- Conflict Ball
- Contractual Genre Blindness
- Credit Card Plot: Someone gets their first credit/debit card but immediately maxes it out.
- Culture Blind
- Curiosity Killed the Cast
- Cut Lex Luthor a Check: The villain uses their powers and inventions to commit robberies when they could easily use their gifts to get money the legal way.
- Cutscene Incompetence
- Damsel Scrappy: A character is disliked for always getting into trouble and needing to be rescued.
- Deus Exit Machina
- Distress Ball
- Ditch the Bodyguards
- Dramatic Slip
- Exhaustion-Induced Idiocy: The character doesn't have enough energy to spare to use for brain power.
- Explaining Your Power to the Enemy: The character makes the mistake of telling their opponent how their powers work, letting the enemy know how they can weaken them.
- Failed a Spot Check: Failing to notice something important, different or dangerous despite being nearby.
- Forgot About His Powers: The character fails to use their super magical abilities for the sake of advancing the plot.
- Forgot I Couldn't Swim
- Forgot the Disability
- Forgotten Phlebotinum: Useful power or device revealed in one episode is never used again.
- Forgot to Feed the Monster: Character finds that the living being or beings they had locked away had starved to death by the time they were needed because the character neglected to feed them.
- Fury-Fueled Foolishness: A character becomes stupid after they get angry.
- Genre Blindness
- Gullible Lemmings
- Guns in Church: Choosing to bring weapons in areas where there is a zero-tolerance policy towards carrying weapons.
- Hand in the Hole
- Have You Told Anyone Else?: Someone gets themselves killed because they revealed that they were aware of confidential information and confirmed themselves to be the only person aware of the secret to someone who most certainly doesn't want the information to be made public.
- Hero Ball
- Holding Back the Phlebotinum (sometimes)
- Holding Both Sides of the Conversation
- Horrible Judge of Character: The character is unable to tell when a person cannot be trusted.
- Idiot Ball: The plot requires a usually smarter character to suddenly act like an idiot.
- Idiot Plot: The only reason the conflict happens at all is because everyone is acting like a moron.
- I Just Shot Marvin in the Face
- I'll Never Tell You What I'm Telling You!: A character refuses to reveal information they've been asked to reveal, but in the process comically reveals the information anyway.
- Inventional Wisdom: Someone for some reason thought it would be a good idea to give the machine an easily-triggered mechanism that serves no purpose other than making the machine self-destruct or causing severe harm.
- It Seemed Like a Good Idea at the Time
- Just Between You and Me
- Just Eat Gilligan: Doing this one simple thing would solve everybody's problems, but then there'd be no plot.
- Left Your Lifesaver Behind
- Lethally Stupid: A character's idiocy causes others to get harmed or killed.
- MacGuffin Blindness: Unable to realize the MacGuffin's true purpose.
- Mad at a Dream
- Made Out to Be a Jerkass: A character retaliates to someone being mean to them, resulting in uninformed bystanders attacking them under the assumption that they were the person being a jerk.
- Mercy Lead
- The Millstone: The plan would go along smoothly if only the team didn't still have this idiot hanging around with them.
- Ms. Red Ink: A character who wastes a lot of their family's/friends' money.
- Neutral Female: An able-bodied woman just stands by and watches a fight in which she has a stake instead of trying to help her side win.
- Never Recycle Your Schemes: It never occurs to the villain that they could make another attempt at a failed scheme while taking measures to prevent the circumstances that led to the scheme failing last time.
- "No" Means "Yes": Assuming that someone meant "yes" when they said "no" when they actually did mean to say "no".
- No Peripheral Vision: The character always looks straight ahead.
- Not a Zombie: Characters encounter a zombie and take a while to grasp that they're encountering a member of the undead in spite of the obvious clues.
- Once is Not Enough: The hero defeats the villain, but leaves instead of making sure the villain doesn't get back up again.
- 1-Dimensional Thinking
- Out-of-Context Eavesdropping: Someone overhears a conversation and mistakes it for something serious when they don't know the full context.
- Out of Sight, Out of Mind
- Paper-Thin Disguise: Someone thinks that wearing Groucho Marx glasses and a funny hat (or some other ridiculous disguise) is enough to trick others into thinking they are a completely different person. Likewise, everyone else is somehow stupid enough to not see through this person's shoddy efforts in disguising themselves.
- Phlebotinum-Induced Stupidity, when used for the purposes of the plot.
- Ping Pong Naïveté
- Plot-Sensitive Snooping Skills
- Poor Communication Kills: A character fails to explain their intentions clearly, resulting in their statements being misinterpreted and causing a whole heap of trouble.
- Quote Mine
- Radar Is Useless
- Reality Show Genre Blindness
- Recognition Failure
- Reed Richards Is Useless
- Remembered I Could Fly
- Revealing Cover-Up
- Running into the Window
- Schmuck Bait: Falling for an obvious trap.
- Selective Obliviousness: A character chooses to remain oblivious of something in spite of seeing evidence of it.
- Sold His Soul for a Donut: A character makes a Deal with the Devil where they relinquish their soul in exchange for something trivial.
- Stranger Safety
- Stupidity-Inducing Attack, when someone's actually trying to create and weaponize this in-story.
- Stupidity Is the Only Option: The only way to proceed in the game is by doing something stupid.
- Stupid Sacrifice: A character sacrifices themselves even though they didn't have to.
- Stupid Surrender: Character surrenders even though there was no chance their opponent could beat them.
- Thinks of Something Smart, Says Something Stupid: Character thinks of a smart thing to say, but says something stupid anyway.
- Third Act Stupidity
- Too Dumb to Live: A stupid character ends up endangering or killing themselves because of their idiocy.
- Trap Is the Only Option
- Treacherous Spirit Chase
- Unusually Uninteresting Sight: Somehow, no one thinks that this unusual thing is out of the ordinary.
- Useless Without Cell Phones
- Valley Girl
- Villain Ball: The villain's undoing is because of their own actions.
- Villain: Exit, Stage Left: The villain gets away in the end. Especially counts if the heroes could've easily stopped the villain before they escaped.
- Violation of Common Sense: Advancing in a video game requires doing things a sane person usually wouldn't even think of.
- What an Idiot!: Audiences lose sympathy for a character after they do something really dumb that they really should've known better than to do.
- Why Don't You Just Shoot Him?: When the villain tries to kill their enemy, they never consider the simpler solutions.
