- Hamlet and its sources are a variant on this. In the original Amleth, the main character feigns madness and an irrational obsession with sharpening sticks. Eventually, he uses these sharpened sticks to help pin down the woolen hangings in a dining hall, setting fire to them and letting his enemies roast alive. Depending on the version, it's never quite clear whether Hamlet is faking being insane, or if he really has gone whackadoodle.
- On another Shakespeare note, Henry IV's Prince Hal, the future Henry V. He made himself out as a teen to be a drunkard completely unfit for the crown, so that when he finally ascended in all its glory, he made it appear as if God himself made him king. In this case it was more like obfuscating debauchery.
- Shakespeare used this in spades. King Lear's Fool and "Poor Tom" (Edgar, disguising himself to avoid his pursuers), Feste in Twelfth Night, Touchstone in As You Like It, and many other jester-like characters. Casca in Julius Caesar, of "it was Greek to me" fame, acts like a moronic clod when around people with questionable motives - when around people who he knows are trustworthy, he becomes an intelligent, potent member of the conspiracy. Hamlet is probably the lord and master of this trope. He plays everyone but Horatio for saps. And depending on how far you're willing to interpret it, he basically orchestrates the entire play.
- Glinda often comes off as a Dumb Blonde to people but is smarter than she lets on, though not to the degree Elphaba is.
- The villains of the piece (including the Wizard of Oz himself) keep up their doting, jovial personas to prevent anyone from antagonizing them.
- Fiyero. Even his Character Song, "Dancing Through Life", implies that he's just putting on an act. It's even more clear when he asks Elphaba if she really thinks he's stupid (util that point in time, she had). She also points out that he's not really self-centered or shallow. After that scene, even Glinda begins to notice that he's not really stupid ("I'm so worried! It's Fiyero! He's been [gasp] thinking!"), self-centered ( he sacrifices himself to save Elphaba), or shallow, and that the whole things was just an act ([about them getting married] Galinda: "But it'll make you happy too, right?" Fiyero: "...I'm always happy" [runs offstage])
- In Hairspray, Corny Collins doesn't act stupid, but rather resigned to the fact that his hands are tied, while secretly prepping events for Tracy and co to revolutionize everything for him.
- In the stage production of Thoroughly Modern Millie, Mrs. Meers' two Chinese employees are a lot more aware of what's going on than she realizes. At the end, it's revealed that the one can understand English "better than [she] can speak Chinese" and thus knew all along that she had no intention of helping them import their mother to the US from Hong Kong. This, of course, leads them to quite willingly testify against her when she's arrested.
- Sir Percy Blakeney in the musical The Scarlet Pimpernel (and every other version of the story as well) is a quick-witted young man who pretends to be a witless fop, the better to hide his war against the excesses of the French Revolution.
- Clearly inspired by The Scarlet Pimpernel, in The Desert Song Pierre Birabeau, the "stupid" Non-Action Guy son of the new French governor of Morocco, is really the dashing Red Shadow, leader of the Riffs in their rebellion against the French.
- In Dorothy L. Sayers' The Emperor Constantine, Constantine and his father are about to quarrel. Helena comments about how Constantine looked just like he did when he was six. The directions note that this is maternal tactlessness — or guile, and it succeeds in derailing the quarrel.
- The prequel installments of the William Shakespeare's Star Wars books reinterpret Jar Jar Binks as this; a radical revolutionary who is playing the role of a classical Shakespearean fool in order to advance his secret agenda of advancing relations between the Gungans and the Naboo humans.
- In The Rivals, Lucy, Lydia Languish's maid is introduced as seeming none-to-bright, being confused by the various popular novels requested by Lydia nor Lydia's use of fashionable language. At the end of the first act, after both Lydia and Lydia's aunt, Mrs. Malaprop, have both referred to Lucy as being simple and/or stupid, Lucy addresses the audience and mocks them, describing how through pretending to be simple and deferential, she's profited by acting as a go-between and playing Lucy and Mrs. Malaprop and their suitors against each other:Ha! ha! ha!So, my dear Simplicity, let me give you a little respite.[Altering her manner.] Let girls in my station be as fond as they please of appearing expert, and knowing in their trusts; commend me to a mask of silliness, and a pair of sharp eyes for my own interest under it!Let me see to what account have I turned my simplicity lately.[Looks at a paper.] For abetting Miss Lydia Languish in a design of running away with an ensign!in money, sundry times, twelve pound twelve; gowns, five; hats, ruffles, caps, &c., &c., numberless!From the said ensign, within this last month, six guineas and a half.About a quarter's pay!Item, from Mrs. Malaprop, for betraying the young people to herwhen I found matters were likely to be discoveredtwo guineas, and a black paduasoy.Item, from Mr. Acres, for carrying divers letterswhich I never deliveredtwo guineas, and a pair of buckles.Item, from Sir Lucius O'Trigger, three crowns, two gold pocket-pieces, and a silver snuff-box!Well done, Simplicity!Yet I was forced to make my Hibernian believe, that he was corresponding, not with the aunt, but with the niece; for though not over rich, I found he had too much pride and delicacy to sacrifice the feelings of a gentleman to the necessities of his fortune.
Obfuscating Stupidity / Theatre