"Be happy that weasels infest the world. Weasels are like motor oil for society. It wouldn't be fair to judge motor oil outside the context of an engine. If you put motor oil in your mouth, it would be filthy and slimy and leave a bad taste. But when that oil is inside an engine, it does an important job and you're glad it's there. Weasels are the same way. Slimy and disgusting, but essential."As a logical extension of Tropes Are Not Bad, many tropes that might otherwise come across as gratuitous, offensive or just plain wrong in most genres are considered not just accepted in certain genres, but are practically a part of the genre. Complaining about the simple use of the tropes (as opposed to particularly offensive variations) in said genres is rather short-sighted and pointless, since, well, it's in almost every other work in the genre. Can often be the cause of an Enforced Trope. Some Acceptable Breaks from Reality are Necessary Weasels to particular genres as well. Contrast with Bad Writing Index, an article listing some real (versus merely perceived) flaws.
— Scott Adams, The Way of the Weasel
- Rule of Cool in general; "realistic" does not always equal "interesting."
- More Dakka, Stuff Blowing Up in summer action films.
- Blatant Wish Fulfillment and Mary Sue characters in Fairy Tales and mythology.
- Invincible Heroes in combat-oriented video games. Depending on the difficulty at least (or the player's skill).
- Toilet Humor in comedies featuring babies.
- An Audience Surrogate character in a Harem anime.
- Anticlimax Boss in Wide Open Sandbox games. If a boss must be fought, and players can be optimized for something other than combat, then the boss must be beatable by the weakest character who can reach the fight.
- Purple Is the New Black, and any other specific attributions of a particular colour to light or darkness (like blue or red).
- The Gods Must Be Lazy and similar tropes, like God's Hands Are Tied and Have You Seen My God? in settings where vastly powerful deitie(s) exist. Such tropes preserve conflict by keeping the story from favoring the good side too much by making it too powerful, and allow for a human underdog hero to step in when the god(s) cannot or won't.
- Will They or Won't They? in stories involving the main character picking a Love Interest. Unless there's something else to generate conflict, this trope will be used to keep the story from ending until They Do.
- Faster-Than-Light Travel: usually present in space-based Science Fiction and virtually all Space Opera. Without it, you can't really go anywhere other than the Solar System, which aside from Earth is made up of some fairly unattractive real estate.
- Aliens Speaking English, whenever the plot is not about first contact with them. Sometimes hand-waved with a Universal Translater device, but either way, the protagonists often need to communicate with aliens, and going back and forth with an interpreter is too clumsy to do all the time.
- Artificial Gravity, for "soft" Science Fiction works (though otherwise "hard" film and especially television Science Fiction will sometimes make use of it due to the extreme difficulty of producing true "zero-g" on camera).note
- Inertial Dampening: Often accompanies Faster-Than-Light Travel (or at least any acceleration/deceleration that can be expressed as ".C"), needed to keep the crew from being rendered a fine paste in high-speed maneuvering or entering/exiting FTL travel.
- No Conservation of Energy in portrayals of Stock Super Powers.
- Ignoring of the Square/Cube Law (as well as other laws of physics) in Super Hero, Humongous Mecha, and Attack of the 50-Foot Whatever stories, as well as some types of Starfish Aliens.
- Instant Expert in Role Playing Games.
- Benevolent Architecture - Sure, there is very slim chance that video game character's surroundings will be perfectly suited to that character's unique powers or abilities. Or that wreckage will form a path, rather than an obstacle. However, being realistic would mean Unwinnable or else easily passed.
- The Perry Mason Method: Because once the audience knows who the real culprit is, there's usually no real reason to continue the story.
- Hitbox Dissonance in Bullet Hell games - otherwise they'd be impossible rather than just Nintendo Hard.
- Jump Physics in platform games.
- Power Creep, Power Seep in Crossover Video Games.
- Masquerade allows the writer to introduce fantastic elements to the story while keeping the setting relatable for the audience.
- Similarly, Reed Richards Is Useless is necessary to keep the larger setting of a superhero world from transforming into Science Fiction with leotards.
- Contrived Coincidence in farce. The more things that go humorously wrong, the better, so plausibility can go out the window.
- Cell Phones Are Useless in a Closed Circle.
- Improbably Female Cast in Magical Girl shows.
- Imperial Stormtrooper Marksmanship Academy - If the antagonists hit their mark, the story would be over.
- Militaries Are Useless in a Zombie Apocalypse because otherwise it wouldn't be The End of the World as We Know It. Can sometimes be avoided however, if the story takes place early on or in a small area, allowing the military to save the day in the end (long term implications be damned); or the zombies are more powerful than usual.
- Orcus on His Throne: Sure, it would be sensible for the Big Bad to personally hunt down The Chosen One. But then the protagonist would get splattered and there'd be no plot.