"The fourth wall is the imaginary wall that separates the audience from the actors on stage, and by removing it, even momentarily, you force people to stop feeling immersed in the fiction, waking them from the spell you’ve cast on them, and generally making them feel silly for getting so carried away with the fiction."
Stephen Colbert: I sometimes feel that my movements are being watched by otherworldly beings just beyond the veil of my perception.
Neil Gaiman: Possibly on the other side of a giant television screen? I have that too.
Carl: This is a cartoon, sir.
Major Monogram: Carl, what have I told you about breaking the fourth wall?
Empowered: We'd better let that poor, abused Fourth Wall recover from all the breakage we've inflicted on it...!
Hey! Yeah, you! I'm down here, busting my ass, while you sit on yours watching me jump around? How is that fair?
I love what you've done with the place. Had the wall removed and all these people put in!
The truth was a burning green crack through my brain. Weapon statistics hanging in the air, glimpsed out of the corner of my eye. Endless repetition of the act of shooting, time slowing down to show off my moves. The paranoid feel of someone controlling my every step. I was in a computer game. Funny as Hell, it was the most horrible thing I could think of.
80s Raphael: (to the camera) Some people just can't handle change.
Hun: (follows his gaze) Why do you keep doing that? Who are you talking to?! There's no one there!
Orihime: Okay, seriously, Mr. Toshiro? You need to quit breaking the fourth wall. That's twice in two chapters.
Toshiro: Don't blame me, blame the hack writing the dialogue! Um... oh, crap, i mean... blame... God?
Orihime: That's three times! That's it, go sit in the corner until you learn to start respecting the laws of the fictional universe.
Ah, welcome back. You may have noticed that this room has begun to deteriorate as a result of narrative contradiction.
— The Narrator, The Stanley Parable