* In what might be a "Crowning Moment of OhCrap", Theatre/{{Macbeth}} has two of these when it dawns on him he might've taken the witch's truths a bit too literally...
** Or, more accurately, [[ExactWords not literally enough]].
* The last scene of ''Theatre/{{Hamlet}}'' has a couple of these. Hamlet has one when Laertes informs him that he's been poisoned by the foil and he's got less than a half hour to live (a lot less, as it turns out). Claudius gets the next one when it becomes clear that the jig is up, Hamlet is finally sufficiently motivated to kill him, and no one's about to prevent it.
* ''Theatre/AngelsInAmerica'': [[spoiler: Roy's death scene]]
* Enjolras in ''Theatre/LesMiserables'' gets one when he realizes that Les Amis are [[spoiler: about to get obliterated by the French Army because no one has come to their aid.]]
-->''The people have not stirred\\
We are abandoned by those who still live in fear\\
Let us not waste lives\\
Let all women and fathers of children go from here''
* In John Willard's "The Cat and The Canary", lawyer Roger Crosby has one of these moments as his last line"
** As does Charlie, when he is unmasked by Annabelle.
* Theatre/SpringAwakening has an entire song about this trope.
* Sir Ruthven Murgatroyd from ''Theatre/{{Ruddigore}}'' has three: When [[spoiler:Richard]] unmasks him (forcing the title and its Be A PunchClockVillain Or Die Horribly curse onto him), one when he realizes [[PokeThePoodle his misdemeanors]] won't cut it and he has to cross the MoralEventHorizon or die, and again when [[spoiler:Dame Hannah]], the maiden [[TheDragon Gideon Crawle]] has kidnapped on his orders, [[spoiler:appropriates a {{BFS}} and challenges Ruthven.]]
* In ''Theatre/TheTamingOfTheShrew'', Lucentio has [[PrinceAndPauper switched places with his servant Tranio]] for the purposes of a ZanyScheme. Eventually, Tranio is told to produce his father and gets a pedant to impersonate Lucentio's dad. Everything's going well until Lucentio's ''real'' father shows up, at which point Tranio, the pedant, and Lucentio's other servant Biondello frantically deny knowing him and try to get him thrown in jail. Just when it looks as if this might actually work, Lucentio arrives on the scene:
--> '''Biondello:''' O! we are spoiled and--yonder he is: deny him, forswear him, or else we are all undone.
--> '''Lucentio:''' ''[Kneeling]'' Pardon, sweet father.
--> '''Vincentio:''' Lives my sweet son?
--> ''[Exeunt BIONDELLO, TRANIO, and Pedant, as fast as may be]''
* In ''Theatre/SeventeenSeventySix'', Franklin and then Jefferson realize that they're in serious trouble when Edward Rutledge asks for clarification about the anti-slavery clause in the Declaration. Franklin mutters "look out" when Rutledge first speaks, and Jefferson abruptly stands up when Rutledge starts to read it.
* ''Theatre/ThePhantomOfTheOpera'' pretty much boils down to the title character causing a series of these reactions in everyone else. FallingChandelierOfDoom, anyone?
* ''Theatre/MarginForError'' has Horst's panicked reaction as it dawns on him that the Consul wasn't joking about having him "rubbed out by a Jew" on his next mission:
-->'''Horst''' ''(His uncritical belief in his heroic destiny is suffering a terrible strain)'': You're trying to murder me! I won't have it! If Berlin's so hard up for a martyr, let them send one over! And they'd better send someone to kill him--\\
'''Consul''': Is the American Fuehrer not prepared to die for his Nazi principles?\\
'''Horst''' ''(Incoherent with fear)'': No!!! I mean--yes--I--I mean, I haven't finished my memoirs yet, I--\\
'''Consul''': The Fuehrer asks nobody to do what he wouldn't do himself.
* In ''Theatre/LaCageAuxFolles'', Albin habitually takes off his "Zaza" wig after performing "The Best of Times," and, suddenly realizing he's unmasked himself to the Dindons, says: "Oh, ''[[GratuitousFrench merde!]]''"
* [[Theatre/{{Hamilton}} "That was my wife you decided to-"]] ''[[PrecisionFStrike "Fuuuuuu..."]]''
* In ''Theatre/TheTwentyFifthAnnualPutnamCountySpellingBee'', this is Barfee's reaction when he discovers that the sticky floor won't allow him to use his "magic foot" to spell the word.
** Chip reacts similarly when [[spoiler:[[SomethingElseAlsoRises he gets an erection right before he has to spell a word.]]]]