Obfuscating Insanity



""Hide behind the mask of a fool, a drunk, or a madman to create confusion about your intentions and motivations. Lure your opponent into underestimating your ability until, overconfident, he drops his guard. Then you may attack.""

- Stratagem 27, Thirty-Six Stratagems

It's pretty much a given that no one takes crazy people seriously. It's also a given that a lot of people give crazy people a wide berth lest they flip out on them. A lot of people are aware of this and choose to take advantage of it, although their reasons for doing so vary from one character to the next. Sometimes the apparent nutcase is actually perfectly sane, other times they actually are a little on the nutty side (or maybe more than a little) but deliberately play it up to the Nth degree so that they appear to be far crazier than they actually are.

Not to be confused with Insanity Defense. Compare Obfuscating Stupidity, where people pretend to be dimwitted instead of crazy.

Anime and Manga

 * In Bleach Urahara loves playing crazy and often goes to great lengths to ham it up. Of course, he still has The Wonka tendencies even when he drops the mask, but that doesn't change the fact he's wearing a mask in the first place.
 * Reign the Conqueror: Diogenes. Whether this also happened in Real Life I do not claim to know.
 * Diogenes was more Crazy Awesome. He prescribed masturbation to prevent sexual immorality, then demonstrated.
 * "If only I could satisfy my hunger by rubbing my belly."
 * Banner of the Stars. Several of the admirals are... eccentric. Sometimes they have crazy ideas that their saner subordinates shoot down; sometimes they have crazy brilliant ideas that pan out. (Or that were good, but don't pan out anyway.) This resonates with a culture of snark, where one suspects they're trying to see how much insanity they can get away with before someone cracks. Bebaus brothers, especially.
 * Many powerful shinobi in Naruto. The longer they've been around, the crazier they get; see Maito Gai, Kakashi Hatake, Jiraya, Tsunade, Anko Mitarashi... and underneath all the crazy is someone who could kill you in the time it takes to blink.
 * Fanon seen in a lot of Fanfic is that high-level ninja tend to develop bizarre quirks as a coping mechanism; the more powerful they are, the more crap they end up going though in using that power, and the stranger the coping mechanism gets.
 * Perhaps best demonstrated with Chiyo, who's laughing like a loon the first time we meet her and her elderly brother, and attempting to attack Kakashi as soon as she meets him. She's crazy powerful, though. Naruto sums it up, "She may be old, but she's good."

Comics

 * The Joker. It should be emphasised that just how much of the Joker's madness is genuine or part of a ploy largely depends on the writer, naturally. He is quite, quite mad, but whether he's an out-and-out loony or just a very driven psychopath with a twisted sense of humour changes from story to story.
 * There was a particular story ("Case Study" by Paul Dini and Alex Ross) that really explored this facet. The story was told from the perspective of two psychiatrists at Arkham, who had found a psychiatric analysis of Joker that revealed him as sane, but faking insanity to get into mental institutions where it would be easier to break free. Hopeful that they can use this to get Joker transferred to a prison, they're disappointed to find out that the person who wrote the analysis was
 * Oddly, this changing personality is also something that exists in-story, after being driven mad. She theorized that he reinvents his personality entirely on a day-to-day basis, so that one day he may be a funny guy with a penchant for stalking the Bat, then the next he's a Complete Monster, then the next he's a glibbering loon. Her madness, of course, shows in her conclusion that the only constant is his love for her.
 * This theory is also put forth in Arkham Asylum a Serious House On Serious Earth by Ruth Adams who equates it as a form of Super Sanity that may be more suited to the end of the 21st century than the here and now.
 * Deadpool also uses this trope to its full advantage, confusing and exhausting his enemies with unstoppable mouth and wacky babbling.
 * Like the Joker, Deadpool really is insane (a different kind of insane, though) and knows it, but he plays up and (possibly) exaggerates his insanity for tactical benefit. For example, against the Taskmaster, whose signature skill is figuring out any opponent's fighting style (and copying anything useful from it). This ability doesn't work on Deadpool because his insanity leaves him with no identifiable fighting style.
 * Also like the Joker, the fact that his personality changes regularly is part of canon. In his case, his healing factor and cancer have combined to leave his braincells constantly in flux. Some stories he's little more than an immature goofball, others he's perfectly capable of commiting murders in cold blood that he doesn't even remember afterward. Of course, as a Meta Guy, Deadpool's also the first to admit that the real reason he changes is who is writing him at the moment.
 * In Cerebus, the Captain Ersatz of Groucho Marx, Lord Julius, is a sterling example of this. Cerebus explains it during a croquet game with someone else: "Insanity is the last defense of the master bureaucrat, but you have to lay the foundation early in the game. It's hard to get a refund from the salesman if he's sniffing your crotch and baying at the moon."
 * "Baskin, my lad! Come in. Whatever it is, I'm against it. Unless I'm for it, in which case the tie goes to the runner."
 * Julius is, mind you, a spot-on recreation of Groucho. In any given Marx Brothers movie, Groucho will spend most of his screen time running rings around everyone else in the room (except his brothers Harpo and Chico, who are always either crazy enough or stupid enough to follow right along) by living in this trope. Nobody (but his brothers) can even hope to keep up with him and as a result he easily gets whatever he wants whenever he wants it. Give Groucho a pair of guns, a sword, a mask and the will to kill and he's Deadpool. Period.
 * Shortly after the Black Cat was introduced, Spider-Man tracked her down ... and discovered she had an insane romantic fixation on him. It turned out a few issues later that she'd realized he was about to catch her and set that up as a cover to get herself locked in a mental hospital rather than prison, as the hospital was easier to escape. But then she found herself obsessing about Spidey for real....
 * Prof. Bartap from German comic Nick Knatterton, to fool some gangsters who wanted to get their hands on his latest invention, a shaving foam which is also a very effective explosive. "Goodbye, you dummyheads!"
 * In the Sin City story Family Values, Dwight used this as a ploy. A female cop was investigating the same crime scene as Dwight and Miho. Since Dwight is a wanted man and he had an assassin ready to kill the police officer, he had to think quick. He started off by flirting wiht her in hopes that she would be offended and leave. Considering Dwight is Estrogen Brigade Bait, she liked the attention and decided to stick around. He then demanded that they go to a hotel where she would spank him and call him Belinda because "that's how Douglas does is." She wonders why she always attracts the loonies and saunters off.

Fan Fiction

 * In Harry Potter and The Methods of Rationality, Dumbledore is widely believed to be using this. It's effective nevertheless, as it not only gives him an excuse to do whatever he wants, it's also impossible to tell the difference between when he's just keeping up the act and when he's executing some brilliant, secret plan right under your nose.
 * In the Firefly fanfic Forward, River deliberately invokes this by pretending to be more unhinged than usual while the crew is preparing a heist, so that they'll leave her off the team. Once they depart, she sneaks away for a personal mission of her own.
 * In My Stupid Reality a Death Note AU where L's people are rounding up genius children for some nefarious purpose, Light attempted to stay under the radar by playing dumb. Later, when it becomes impossible for Light to deny that he's a genius he tries to get out of L's program by deliberately failing the psych exam by pretending to be a homocidal maniac who believes all criminals should die. Unfortunately he failed too well and L knew he was faking.

Film
"Ferocious, aren't I?"
 * Star Wars: Yoda pretended to be a random senile alien, as a Secret Test of Character for Luke when they first meet.
 * Captain Jack Sparrow from Pirates of the Caribbean. Exactly how much is obfuscation and how much is Crazy Awesome is unclear. Just the way Jack likes it.
 * Al Pacino as Vincent Hanna in Heat.


 * In Primal Fear, Aaron Stampler pretends to be insane in order to get away with murder.
 * In fact, he does such a good job that he's got the psychiatrists fooled
 * John McClane has to fake this in Die Hard With a Vengeance, when a madman makes him wear a billboard insulting Afro-Americans while in his underwear. His future partner in adventures saves him by claiming his insanity, and he runs with it.
 * And in general, McClane has his moments where he appears "unhinged". He does this for various reasons, either to fool and confuse his enemies, or to cope with the crap he has to go through.
 * A similar thing happens in Johnny English where the title character, a secret agent, mistakes a group of mourners for jewel thieves. His assistant Bough comes to his rescue and tells the mourners that English is an escapee from a lunatic asylum.

Literature
"Biff: I have to go find Joshua.
 * Treasure Island: Ben Gunn
 * John Christopher's YA SF The Tripods series--the hero and his cousin are first informed of the resistance's existence by a wandering man who appears to be crazy. If I remember, he informs them of the resistance in a speech to them that includes the phrases "And I was born on a rainy morning" and "My name is Ozymandias, King of Kings ..." as camouflage.
 * Invoked in Catch-22, though averted with the eponymous Morton's Fork.
 * The old king in Once Upon a Marigold realizes that his evil and abmitious wife is slowly poisoning him. But even though he throws out his daily "medicine", he pretends to be crazy and senile as well as sick so he can keep a watch on her without arousing her suspicions.
 * There was an SF story in the '40s or '50s, "Clerical Error," in which a psychiatrist gets himself "accidentally" locked up with an insane patient so he can talk to him.
 * Justine of The Dresden Files actually was deeply mentally ill when she was first introduced, but when she eventually recovers, she keeps up the act in order to act as a spy on the White Court for Thomas.
 * Don Quixote: In Part II, Chapter XI, Don Quixote claims to from a child I was fond of the play, and in my youth a keen lover of the actor's art.". Several critics have toyed with the idea that Don Quixote never lost that passion for theater and behaves like an actor: Don Quixote uses this trope because he does not believe to be a knight, but pretends to be one, as if he's on stage.
 * Wonko The Sane from the fourth Hitch Hikers Guide to The Galaxy book.
 * Firebird: Ilya has to do this to avoid being killed.
 * Bartholomew the Village Idiot/Cynic in Lamb: The Gospel According to Biff, Christ's Childhood Pal, though the "obfuscating" part is... questionable, especially when considering conversations like this:

Bartholomew: You know he is the Messiah, don't you?

Biff: Wait a minute, you're not a Jew-- I thought you didn't believe in any religion.

Bart: The dogs told me he was the Messiah. I believe them. Tell Joshua I believe them..

Biff: The dogs told you?

Bart: They're Jewish dogs."


 * Temple of the Winds: A powerful wizard/sorceress combo are captured by a magic nullifying savages who want to sacrifice them. Solution? Pretend to be completely insane so the tribe won't consider them a proper sacrifice. Instead, they are sold to slavery... where their lack of working skills gets them sold again... to cannibals.
 * Brilliantly done by in The Culture. Basically, the Culture needs a hidden stash of weapons that can move quickly, build quickly and not attract attention. The solution?  It works beautifully.
 * The method used by the Platinum Dragon god Paladine to aid the heroes as Fizban the Fabulous in the Dragonlance novels.
 * In Jeeves and Wooster, Jeeves sometimes employs a variation by telling people that Bertie is insane to get him out of trouble. By the end of The Inimitable Jeeves, Bertie estimates that about half of London must now think he's off his rocker.

Live Action TV

 * Jack of All Trades had King George act insane to throw off Napoleon.
 * Murdock in The A-Team, was truly mad thanks to PTSD. His team had to break him out of a mental institution in almost every episode. However, at times he faked more extreme insanity to get into an asylum in order to break someone else out, or take down a gun smuggling ring or something. Of course, he might have exaggerated the problem more regularly for the free accommodation and the nurses, or just to irritate B.A.
 * When the situation called for it, Murdock could act completely sane and coldly competent. In the Season 5 premiere episode, Murdock delivers a pair of hired goons, handcuffed, to General Hunt Stockwell -who'd sent them after Murdock. Murdock says that their buddy will check in as well, once he checks out of the local emergency room. Stockwell smiles and says that the psychiatrist who diagnosed Murdock as insane should have his licences permanently revoked.
 * Murdock was eccentric and likely did suffer from some form of PTSD, but was definitely not mad. In one episode, his psychiatrist even calls him out on it that he knows Murdock is sane and simply putting on a VERY good act. Faking insanity not only gave him free room and board at the VA, but also could be a safeguard against any criminal charges. Most of his "insane" actions seemed designed more to deliberately irritate B.A.
 * Stark from Farscape was pulling this off when John first met him (he's of the 'actually is a bit off' variety by the way).
 * Crichton is also on the brink of insanity, but except the actual, uncontrollable consequences of Scorpius being inside his head, he's mostly faking insanity, and sometimes running with it.
 * Dave on News Radio feigns insanity whenever he wants Matthew out of his hair. He then passes the tip on to Lisa, who passes it on to Beth, who tells Matthew, who wonders if anyone's ever done it to him.
 * Not exactly insanity, but in Just Shoot Me, Elliot's brother Donnie fakes being mentally handicapped to leech off everyone else.
 * A season 5 episode of Supernatural has Sam and Dean break into an insane asylum by telling their life story.
 * The Doctor, particularly in his fourth and eleventh incarnations. He's very much of the genuinely a bit nutty variety -- his eighth incarnation, in the novels, has difficulties remembering that TV is not Real Life and consequently runs the risk of being Driven to Suicide by Eastenders. However, no matter just how capriciously, adorkably batty The Doctor is, there is always that moment when he goes deadly serious, and then you remember that this seemingly flighty alien is capable of bringing thousands of alien ships to a standstill, is responsible for multiple genocides and has saved countless billion lives and - oh yes - the very fabric of the universe itself. He doesn't look quite so adorable now, does he?
 * In Ned's Declassified School Survival Guide: In the "Bullies" episode, Gordy advises Ned to act crazy so Loomer will be too scared to beat him up. It works to degree; Loomer isn't scared, but too wierded out to do beat Ned up.
 * Corporal Klinger of M*A*S*H was all about this trope, spending the first six seasons of the series attempting to secure a Section 8 discharge through a variety of methods (most notably donning women's clothing).
 * In the Black Adder Goes Forth finale, Blackadder plans to try this to get out of the Big Push (putting his underwear on his head and sticking pencils up his nostrils), but is forced to change his plans when he overhears General Melchett say he had to shoot an entire platoon for doing the very same thing (via the very same method).
 * As he later tells Baldrick just prior to going "over the top", it was bound to fail anyway: "I mean, who would have noticed another madman 'round here?"
 * Lord John Marbury in The West Wing, although it's unclear whether he's this trope played straight or a Cloudcuckoolander who pretends to be even crazier than he actually is.
 * Helen Magnus pulls this in the Sanctuary episode "Veritas" by actually making herself a bit crazy with the aid of some Applied Phlebotinum.
 * In Firefly, Jubal Early hides a dangerous intellect behind a veneer of philosophical ramblings and eccentric behavior. It's also not clear when River is doing the same or is genuinely being crazy.
 * Legend of the Seeker, Zeddicus Zul Zorander (Zed) is known as 'that crazy old guy who talks to his chickens'. As it turns out, he saved the Titular Hero's life as a baby, broke through a magical barrier, and brought him to a loving family. He's also a very powerful wizard.

Music
""I went up there, I said, 'Shrink, I wanna kill. I mean, I wanna kill. Kill. I wanna see blood and gore and guts and veins in my teeth. Eat dead, burnt bodies. I mean, kill. Kill. KILL! KILL!' And I started jumpin' up and down, yellin', 'KILLLL! KILLLL!' And he started jumpin' up and down with me, and we was both jumpin' up and down, yellin' 'KILLLL! KILLLL!' And the sergeant came over, pinned a medal on me, sent me down the hall, and said, 'You're our boy.'""
 * In Arlo Guthrie's "Alices Restaurant", he describes attempting this during his Vietnam War draft registration.

Religion And Mythology

 * According to the Trojan Cycle, Odysseus Odysseus really did not want to go to war in Troy, and attempted to invoke this trope by sowing and ploughing his fields with salt. Palamedes saw right through the ploy, and ensured that Odysseus didn't dodge the draft by dropping his baby boy Telemachus in front of the plough's path. Considering what happens to him afterwards, though...
 * The worst part is that in some versions, he gave Menelaus the idea and authority to draft everyone else should Helen be abducted.
 * In The Bible, David (of David and Goliath fame) was forced to flee (from Saul) into exile at the court of the King of Gath (Goliath's hometown), who happened to be an enemy of Israel. When the King of Gath recognizes him as an anti-Philistine guerrilla warrior, David pretended to be a raving madman, causing the king to think him harmless.

Theater

 * The title character of Hamlet. Among his tactics were absurd self-contradictions, irrational and sudden tirades, and general oddness. How much of his insanity is simulated, is the subject of some debate. Depending on how you look at it, the same might also apply to Ophelia.
 * Edgar's masquerade as "Tom O'Bedlam" in King Lear.
 * After first meeting Freddie in Chess, Molokov decides that he must be insane, and therefore easy to beat, but Anatoly thinks he's trying to pull this trope: "That's the problem - he's a brilliant lunatic, and you can't tell which way he'll jump. You can't dissect him, predict him... which of course means he's not a lunatic at all." It turns out that Freddie is just as screwed-up as all the other characters are, if not moreso.
 * Petruchio from The Taming of the Shrew, already somewhat eccentric, puts everyone under the impression that he's stark staring mad as part of his plot to tame Katherina.

Tabletop Games
""They. Are on. To us.""
 * Malkavians use two different levels of this.
 * First, all Malkavians are innately insane, but most of them also have psychic visions of the future. But those who do obscure their visions by acting so crazy that only their allies who are in the know would trust any of their rantings.
 * Secondly, the majority of them exaggerate the degree of their crazy--for example, a Malk with mild hallucinations will pretend to be wildly schizophrenic. This is so that their fellow vampires won't take them seriously or see them as a threat until they suddenly turn incredibly calm and lucid.
 * The only vampires who have caught onto the Malkavians' Obfuscating Insanity are those of the Tremere clan, and the Malkavians are aware of that.


 * Players of Malkavians also exploit this since people are less likely to expect you to account for your actions if you're playing a Malkavian, which can make for a smoother gaming experience. Bad players doing so can gain reputations as Cloud Cuckoolanders.

Video Games

 * from Ace Attorney did this, but having to keep the act up for so long strained him immensely and.
 * from The Reconstruction fits this trope to the T. She allegedly destroyed he mind by "peering into the unknown", but it was all because
 * Far Cry 3 has an interesting variation of this trope explained to Jason (our protagonist) by the main villain Vaas near the beginning of the game. Vaas explains in a rather eloquent fashion that insanity is defined as repetitious cycles of behavior done with the expectation that a different result will come from it. When he first heard that he thought it was "bullshit" and even shot the guy who told him that. Actually taking time to look at people around him Vaas realized that insanity is the norm for humanity because people really do have everyday moments of insanity that they don't even realize that they commit, so in actual fact Obfuscating Sanity is the fake persona because deep down everyone is insane in some way. A major theme of the story is the idea that men being left to their own devices without civilization to bog them down will become immoral animals and do whatever they want, this is explicitly pointed out by the developers that Vaas is supposed to unsettle us because it makes us wonder if it might be true that we might become something vile like him if we were left to our devices.

Webcomics

 * Drow Tales: [[http://www.drowtales.com/~wiki/index.php/Mel
 * Lord Shojo, ruler of Azure City in The Order of the Stick, deliberately pretends to be senile so that his enemies don't try and assassinate him. If he does what they want, they assume that they manipulated him, while if he doesn't do what they want, they assume that he is being manipulated by one of their enemies. He also uses this so that his paladins don't get suspicious if he takes actions that would break the Sapphire Guard's restrictive code of honor if people thought he was making them lucidly. His legal adviser, Mr. Scruffy, is an ordinary housecat.
 * In the Stick Tale "The Tragedy of Greenhilt, Prince of Denmark", Prince Greenhilt (Hamlet, played by Roy) and Shojonius (Polonius, played by Shojo) both pretend to be crazy. Gets a big lampshade after Greenhilt kills Shojonius.
 * In this strip of Wapsi Square, Bud uses this method to keep police officers from asking questions about a loud boom and flash of light. It was actually caused when she threw an object into the sun.

Web Original

 * In Kate Modern: The Last Work, does this to fool Gavin into thinking he's harmless.
 * Dr. Clef is unable to be photographed, gives his name as a chord on a ukelele (making him a habitual lyre) and is perhaps most adequately described in an interview where he freaked out the psychiatrist. He's also a senior agent and a Magnificent Bastard, so don't mess with him.
 * He also sometimes claims to be The Devil--though immediately proceeds to go over the top until this is dismissed completely--and has just enough of suspicious incidents to make this hypothesis plausible.
 * "Hello, my name is Dr. Phineas Waldolf Steel and I'm crazy. At least that's what they tell me. It's a real load off of my mind, too. I mean, you can get away with pretty much anything if you're bonkers. It really relieves a lot of pressure and responsibility for me."
 * Survival of the Fittest: When she first appears on the island, Liz Polanski's first actions are to make herself appear as Ax Crazy as possible to ward off potential attackers. How does she do this? By, among other things, smearing her face with make-up and severing the head off one of her classmates' corpse and carrying it around for a while.

Western Animation

 * Avatar: The Last Airbender:  pretends to go insane when he's imprisoned, to a rather disturbing effect. He does drop the act for one particularly friendly, kind guard - but when nobody's looking, he's actually
 * King Bumi is a poster boy for this trope.
 * Keep in mind, Bumi is exactly as insane as he appears. It's just that he is just as competent as he is crazy.
 * Looney Tunes: In "Hare Brush", Elmer Fudd apparently thinks he's a rabbit, while Bugs Bunny (who'd been lured into taking his place in the asylum) is "cured" to think that he's Elmer Fudd. The cartoon ends with Bugs-as-Elmer being hauled off to face tax evasion charges, after which Elmer-as-rabbit tells the audience, "I may be a screwy wabbit... but I'm not going to Alcatwaz!"
 * In season 4 of The Venture Brothers, General Trayster tells Hunter Gathers that his office is trashed because he's been turning into a Hulk following gamma ray therapy for his cancer.

Real Life

 * Richard Feynman, at least according to his autobiography. Well, he was first diagnosed as "mentally defective" by an army psych, then decided to play along a little. Not that this opinion wasn't mutual -- he would have a good chance to be elected as Patron Saint of "Hard On Soft Science" movement.
 * According to at least one history book, an ancestor of Sun Tsu was arrested and imprisoned because of a jealous rival and feigned insanity, eventually to the point of faking his own death.
 * Another assassin in approximately the same era also feigned insanity to get close to his target. (He got called on his bluff and didn't make it.)
 * Lewis Black invoked this trope in his special "Red, White, and Screwed" on how to deal with terrorism. Paraphrasing: "The only way to defend against crazies is to scare them by acting crazier than them. I should know: we New Yorkers do it all the time." His solution to out-crazy Islamo-terrorists? Elect a dead President: preferably Ronald Reagan.
 * Elizabeth Van Lew, a Union spy during the American Civil War who acted like a crazy homeless person so that the Confederates would leave her alone.
 * Kenneth Bianchi, one of the Hillside Stranglers (the other was his cousin, Angelo Buono), tried faking multiple personality disorder to get out of standing trial for his crimes. It didn't work.
 * At least one WWII prisoner-of-war at Colditz tried to escape this way - his acting was flawless, but the Germans never repatriated him.
 * In the TV series based on Colditz prisoners' experiences, the man was repatriated - but it turned out he had actually driven himself insane with the depth of his acting.
 * Vincent Gigante, a.k.a. "The Oddfather", feigned insanity to escape prosecution. He wandered the streets of Greenwich village in a bathrobe and slippers, muttering to himself; psychiatrists testified he was clinically insane. Eventually his "bug act" failed, and he died in prison doing a twelve-year sentence.
 * There's a Law and Order episode that, of course, mixes this plot up with Henry Hill writing Goodfellas. A mob guy in Witness Protection is killed, and the Don who's supposedly responsible is currently in the grips of Alzheimer's. That is, until the prosecution discovers a passage in the mob guy's novel where said Don said that if he ever found himself prosecuted, he'd fake mental illness...
 * Alan Moore allegedly wrote up false reports of himself being a child murderer and other horrible things, then sent them to magazines under a fake name so people would think he's insane and won't approach him if they encounter him in public.
 * Rob Liefeld, on the other hand, thinks that Alan is doing this all the time.
 * The first woman reporter, Nellie Bly, pretended to be crazy so she could get committed and write about lunatic asylums from the inside. It worked too well. She couldn't convince the doctors she was sane when she wanted to leave. Her editor had to come in with a couple of lawyers. She wrote about brutality, beatings, unsanitary conditions, ice cold baths, lousy food and all the ways that the inmates were denied any sense of self-respect or humanity. The book she wrote is still in print.
 * The Rosenhan experiment. Psychiatrists and students tried to do what Nellie did almost 100 years later. Like her they had no trouble getting in, though leaving was less of a problem. It's partly the reason the DSM-III was introduced (and of course, subsequently the current model DSM-IV).
 * There's a lot of stuff in that book that reformers argue is normal behavior that has been designated as crazy so insurance companies would pay off. Every edition is bigger and more complex. Some of the editors for the DSM-V have come out with concerns that the DSM-V diagnoses relatively normal behaviour as well.
 * After his arrest, Russian serial killer Andrei Chikatilo tried this, acting absolutely batshit in front of investigators and in court, though when alone, he acted completely normal.
 * World War I pilots sometimes used a technique called "jinxing" -- flying like you have no idea what you're doing. In addition to any possible psychological edge it offered, jinxing made you unpredictable and thus harder to shoot down.
 * This caught on to such a degree, it evolved into the concept of jinking, a series of quick, evasive dodges and turns specifically designed to avoid gunfire.
 * Pro wrestler Brian Pillman is a prime example of this. He developed his "Loose Cannon" gimmick of behaving incredibly erratically, not just at shows, but everywhere he could, to make people genuinely believe he was a nut, in order to get WCW, the company he was working for, to "fire him for real" (as in, send him a real release for a fake firing), which he immediately signed and jumped ship. Before his death, he only let a handful of people he truly respected in on how deep into character he was, and not actually insane.
 * A Soviet man avoided being drafted to fight in Afghanistan by studying textbooks on mental illness, and then faking it. It worked, but he wound up feeling crazy in the Soviet mental hospital. He eventually wrote a memoir about it, Teach Yourself Madness.
 * It's entirely possible that Libya's former dictatorial leader, Moammar Gaddafi, was doing this. He was known to behave very bizarrely and might also have been Obfuscating Stupidity, but Wikileaks cables reveal that he was quite the Manipulative Bastard, playing off any number of rivals, subordinates, and his own family members against each other.
 * Of course nothing prevents him from having been both completely nuts, yet still politically savvy. He wouldn't have been the first ruler to combine the two traits.
 * In 1200, the English village of Gotham (not that one) in Nottinghamshire learned that King John wanted to build a hunting lodge nearby. This meant that the road through the village would be a royal highway, which would mean anyone travelling on it would have to pay more tolls and taxes. So the entire village pretended to be mad, by attempting to imprison a cuckoo by building a fence round its tree, drowning an eel, and trying rake the moon out of the village pond. Justified by the fact that in the Middle Ages, insanity was believed to be contagious, and therefore a) the idea of an entire village going mad was perfectly believable and b) no-one in their right mind would go anywhere near the place. The hunting lodge was never built.
 * During Queen Elizabeth the First's trip around England, one household feigned madness en mass in an attempt to avoid the large price of hosting the Queen. It worked.