- Escape shows that the hospital staff looking after Murdock know full well his friends are breaking him out each time they do so. They simply allow it because Murdock's not a danger to others and being with his friends improves his moods. Of course, there's also the betting pool they have going on how he'll be broken out each time.
- Italy, of all people, in Heta Oni.
- In Human Curiosity, America pretends to be tactless and unaware that he's pissing off Arthur Kirkland, in order to pull off Arthur's sunglasses and see if he really is England. It's noted that one of the good things about America tending to be The Ditz is that no one notices the rare instances when he's only pretending to be stupid for his advantage.
- In the third arc of the Contractually Obligated Chaos series, Beej notes privately to himself that he enjoys persuading others that he's incredibly dim, as it leads them to underestimate him. He's actually very intelligent, coming up with several clever ideas throughout the series, but he tries to keep it from everyone except those closest to him.
- Cordelia in And Another Thing I Hate About You is one of the only people to notice Anya is doing this. As she puts it, Anya couldn't have interacted with humans for over a thousand years and trick them into making wishes if she really had No Social Skills. Anya admits she just likes messing with the Scoobies.
- Kyon, in Kyon: Big Damn Hero. He is shown to be highly fluent in English, easily beating the brigade in Scrabble, very skilled in chessnote , and invokes Gratuitous English. He also learns German from Tsuruya extremely quickly. Aside from language skills, Kyon also managed to convince a renegade time traveler to pull off a Stable Time Loop for him, or risk being killed, because Kyon can go back in time to take his place, thus rendering his Contractual Immortality moot.
- Cruise Control in Turnabout Storm. This particular case is more Played for Drama than usual, as they had seen themself more or less forced into it thanks in part to Ace Swift blackmailing Cruise into losing to him. Cruise thought the whole act would be more believable if he thought and acted like a general loser as well.
- Princess Peach, of all people, in Link's New Look
- Darcy Lewis in Child of the Storm. No one expects someone that looks like her and talks like her to be smart, perceptive and armed with a taser, and there is a good deal of evidence that she uses it to her advantage.
- In Origin Story, several members of The Avengers finally notice that the entire point of Spider-Man's generally immature attitude is to make people underestimate him. After he makes one particularly insightful observation about the situation, he reminds The Avengers (who are all sitting there staring at him in stunned surprise) that he has two Master's degrees and is close to earning his PhD.
- Kakashi in From His Excerpts by Phoenyxx. Kakashi speaks fluent English, but hides it from the professors, resulting in little gems like these:
Oh. Professor Flitwick chuckled lightly, "I believe the correct term is squib."
"Yes, squid. It is what I say."Death Note
- Light in My Stupid Reality has faked being Book Dumb all his life in order to protect himself from L. He has it down to an art:
Light: One does not just randomly select a question or 2 and try to get them wrong. No. Nor do you do it to every 4th question or some other such ridiculous, predictable pattern like that. The key lies in, like all things, strategy. You need to choose ahead of time a subject or 2 you're awful at, a few you're neutral, and 1 you're good at. Then whenever you get homework, consistently get the same basic principals wrong, and get it wrong on the test as well. Also, you have to make a show of not paying attention in class, or else suspicions will be raised, and you'll be given a special "learning disability," and assigned a tutor pronto.
- A few fanfic authors like to play with the idea that Kogoro Mouri is aware of what Conan is doing, or faking being asleep. Has a basis in the simple fact that being injected countless times with the same sleeping drug will eventually result in the body resisting it.
- Crabbe and Goyle are quite commonly described as doing this. Sometimes they are just shy or quiet, and that combined with their appearance, their love for food and their status as Draco Malfoy's cronies make people think they are stupid. Other times they are actively pretending to be stupid so that people won't expect anything of them. In both cases they either actually like Draco and he likes them, or they protect Draco physically (as is implied in canon) and he protects them socially. In one particular fic, they weren't stupid, but since they suffered from undiagnosed dyslexia, everyone thought they were.
- In Whispered Words Harry fakes a head injury in an attempt to make Dumbledore and the rest of the Wizarding World leave him alone and not drag him into their war.
- In Take No Umbridge, Trelawny's "side-show fortune teller" mannerisms aren't just an act, but one required to ace the Divination practical.
- In Boys Do Tankary, Gage pretends to be drunk (although he genuinely is The Alcoholic) when Vincent comes into the bar to recruit him as the parts coordinator, so that Gage can confirm that Vincent was the one who killed Nyra.
- We're Gonna Get There Soon: Derpy isn't a genius, but she's more aware of what other ponies say and think of her than they give her credit for.
- Naruto status as dead last in the academy and Idiot Hero everywhere is at times depicted as this in most fics. However, the reasons as to why are what really make it enjoyable to read. For example:
- In Blind the Hyuuga train their kids at the age of 3 (according to this fic that's the youngest you can mold charka). Naruto just so happens to be Hyuuga Hiashi's adopted guest/son and he and Hinata can pass the Genin Exam with flying colours. The problem however is that Hinata is blind so her clones and henges come out black and white so she can't pass thusly her class and villagers (except Hiashi. He's is a good father here) brand her a dope. Naruto keeps failing (Hiashi himself has been teaching Naruto to be a hyper-competent ninja) to stay with her while developing a jutsu to help her see. It should be noted that Hinata knows one of the Second Hokages jutsus and Naruto knows Kage Bushin and the Hiraishin.
- In Legacy of the Rasengan Naruto is a creator of simple-to-use yet effective jutsus (simple as in easy to activate and tweak), thinks before he acts, is very observant but acts like his canon self to hide it. The only ones who know (at first) he is playing dumb are Kakashi (due to Naruto outwitting him during the bell test and carefully observing Naruto "Take in information, process it instantly, then act in a manner expected of his buffoon self." ), Hinata (he doesn't put up the charade when they're alone together) and Shikamaru (connected the dots like Kakashi). As is common with the trope they call it dumb luck if he pwns with wits/acts unusually perceptive and jaw-drop when he shows jutsu. Everyone eventually figures it out during the Chunnin Exams after he displays a jutsu that works like Jyuuken and CLEAVES THROUGH NEJI'S ROTATION!
- Kaede Mizuno in A Growing Affection operates using this trope, she wants her enemies to think she is just a pretty face who was promoted due to her family connections. She is in fact quite intelligent, and goes toe-to-toe with some of the strongest characters in the story.
- Naruto, once again, in Kitsune no Ken: Fist of the Fox; here, he behaves like this from the first chapter, when he's just arriving in Konoha Town, acting like a very clueless newcomer to avoid being beaten up by Dosu, Zaku and Kin even as they're trashing the Yamanaka greengrocery, and then in the second chapter he's acting as though he's terrified of being beaten up by other Konoha High students for mouthing off to them. The "obfuscating" part comes in when it's revealed that this is the same guy who was part of the Kyuushingai, a nine-member group that caused panic across an entire continent for a whole year's worth of time, and who are all smart enough via artificially-implanted intelligence to master several fighting disciplines and use of weapons, among other skills.
- In First Try Series Sasuke thinks Naruto was doing this during all his time at the Academy. In Team 7, he recalls how many of Naruto's pranks and failures at the Academy would take out Chunin and that Naruto would say he was "joking". He recalls that after Itachi, there was an age limit for early graduation put in place and recalls from historical precedent that bored ninja not allowed to promote were often very destructive like Naruto. He is very wrong.
- In A Teacher's Glory Sakura and Naruto create a variation of the Sexy Jutsu that weaponizes this. The first time Naruto uses it, Sasuke thinks 'the person who would create something this stupid is so stupid that, if I left them here in this clearing they've been a hundred times before, they'd never find their way home.'
- Advice and Trust: After getting together Shinji and Asuka start to figure out several secrets of Nerv by comparing their pasts and their experiences piloting their Evangelions, but since they realize they are not supposed to know about them and they are trying to keep their relationship under wraps they pretend they are clueless and oblivious to not draw unwanted attention to themselves)
- A Crown of Stars: In chapter 48 Misato pretended to be a silly, gullible, clueless, harmless woman to lure the warlord that ruled Buenos Aires into a trap.
- Once More with Feeling: Time-traveller Shinji goes out of his way to act completely inept in his first combat simulation (and does such a good job of it that the staff nicknamed him "Godzilla''), then asks for a week of training combat training so he can have a more believable explanation for his piloting skills.
- The Second Try: Shinji and Asuka pretend they are dumb, oblivious and ignorant to everything that is happening around them so Gendo does not suspect they are time travelers are plotting to ruin his and Seele's plans.
- Thousand Shinji: Shinji pretended he was dumber and more ignorant than he was so nobody figured out what he is - a master manipulator with Psychic Powers - or what he really knows. Later Rei and Asuka make the same thing, advised by him.
- In With Strings Attached, the four all pretend to be naïve, useless fools when they first start journeying with the Hunter, because they take a massive dislike to him the moment he enters the scene. Their intent is to gradually reveal their power as they travel so they can humiliate him. This turns out not to be the best idea they ever had.
- During the late '90s, Usagi of Sailor Moon practically ruled this trope. It was all the rage for fanfic writers to make Usagi into a God-Mode Sue who was only pretending to be an idiot, often by leaving the Inners and dropping the act. That she still can't write proper hiragana as queen and routinely swipes her kid's candy in the canon is conveniently ignored.
- She is The Ditz in the anime, but shows that she is actually pretty smart in the manga, especially as it goes on and the burdens of leadership take their toll. Venus can be considered another case as well, since it is hinted that she speaks fluent English, a language that is just as hard for the Japanese to learn as their own language is for native English speakers. (They're in completely different language families, so have no common baselines).
- In this Underswap video, Temmie (who has Flowey's role, and vice versa) plays dumb in an effort to lower the player character's guard so he can more easily kill them.