In schools, the teacher's lounge is essentially a break room: A place for the faculty to enjoy time away from their duties as teachers of society's next generation. But from the students' perspective, the only thing they know about the Mysterious Teachers Lounge is ... well, that they don't know what exactly lies beyond that locked door.
So in school settings, expect to see characters occasionally discuss and debate the possibilities of what might be inside. If enough characters get involved, they may even plan to actively break in and discover for themselves what sorts of secrets are hidden therein.
In more faculty-centric shows, someone may make an issue out of use of the teachers' lounge by support staff; in real life it's usually officially labeled as "Faculty/Staff Lounge" or some such even if nobody calls it that, for that reason.
Fun fact for today's kids: During the years between teachers not being allowed to smoke in the classroom, and teachers not being allowed to smoke in the school at all, the teachers' lounge reeked of cigs, and the smell was noticeable well into the hallway leading past it.
Compare Wondrous Ladies Room, a similar place in which no man has gone before.
- In the "Teachers United" strip in the British comic School Fun, the teachers have an Elaborate Underground Base accessed through a 'Staff Only' cupboard.
- In The Faculty, Casey and Delilah break into the teachers' lounge in order to get a story for the school newspaper. This isn't the first time they'd done this; Delilah had gone in there before to discover that one of the teachers was drinking on the job. They wind up finding the corpse of Mrs. Brummel in the closet, as well as Coach Willis and Mrs. Olson infecting the school nurse with the alien parasite.
- In the Wayside School books, the teacher's lounge is referred to as a secret place where students shouldn't come.
- Features in the Jennings books. In Thanks to Jennings, owing to a sitcom-style misunderstanding, the boys become convinced that the teachers go up to the room after dinner in order to secretly snack on a second course.
- In The Best School Year Ever by Barbara Robinson, one kid starts a rumor that any kid who gets into the teachers' room will never come out again; this leads to everyone being terrified of the teachers' room and refusing to go anywhere near it.
- The Uncommon Room at Unseen University in Discworld really is one. There are comfy chairs and lots of food is always brought in. Interestingly, we're seeing it from the faculty perspective, as students at UU are largely ignored (by their professors as well as the narrative, in fact.)
- In Speak, Melinda lampshades this when she and Heather are going to spruce up the teacher's lounge, wondering if there's a secret file cabinet full of student records, beds for teachers wanting a nap, or boxes of tissues for those who get nervous breakdowns. Turns out it's just a sparsely decorated and very plain room with a few chairs and a table.
- iCarly: "The Teachers Lounge", where Sam breaks in, and the icky gross teachers have affairs with each other.
- Ned's Declassified School Survival Guide: When the door opened, dance music and disco lights could be seen and heard from the hallway along with smoke pouring out.
- Everybody Hates Chris: the teachers lounge is a beatnik cafe where the teachers smoke, drink, and perform poetry.
- Nick Hancock referred to this trope on Room 101, and how disappointed he was when he actually became a teacher and learned that the only secret about the staffroom is that as soon as they enter it, all teachers become obsessed with biscuits to the exception of all else.
- In Mr. D, Gerry argues that the school librarian shouldn't have access to the teachers' lounge. To be fair, said librarian tends to hog the microwave.
- In Community episode "Introduction To Teaching", Jeff is invited to the Greendale teacher's lounge, which is run like an exclusive club. So exclusive, in fact, that Dean Pelton isn't allowed to enter, which pleases Jeff.
- Recess: one episode involves this, and the gang expects it to be some sort of magical place, but is subverted when they actually see just being a normal room. Double Subverted when they leave it, and one of the teachers presses a few buttons on the vending machine, revealing a hidden room with a spa.
- A Pepper Ann comic in Disney Adventures uses this trope as the basis for its plot. When she is allowed to actually visit the lounge, her expectations on what it contains were crushed. After she leaves, the teachers reveal a secret luxurious room of the lounge.
- On an episode of Arthur, we get a series of crazy imagine spots about what goes on in the lounge, complete with Lampshade Hanging: "And that's where our tax dollars go!"
- A Daria tie-in book depicts the teacher's lounge, complete with broken-down furniture, ugly colors and evidence of fighting between the staff. Daria opines: "Students aren't allowed in here. They might find out how depressing it is to be an adult."