Offstage Waiting Room

"Meanwhile back at the ranch... nothing interesting happened."

Bob, Alice, and Chuck are on the middle of an epic journey to beat the Big Bad and prevent the The End of the World As We Know It, but, horror of horrors, Bob's powers aren't up to par. Three months and a Training Montage later, he comes back ready to kick some ass. But what were Alice, Chuck, and the Big Bad doing while Bob was away? Surely, there will have been some major changes while he was gone... Nope! They've just been sitting in the Offstage Waiting Room waiting for Bob to come back so they can get on with things.

Whenever there's a Time Skip and one or more characters don't seem to have been doing anything during the break, they are said to have been waiting in the Offstage Waiting Room. This gets particularly noticeable when the Time Skip occurs in the middle of a Story Arc and they really should be doing something to advance the plot or otherwise prepare themselves, but they just... weren't. If these gaps are particularly noticeable, they may lead to some... interesting fan theories about what happened during the jump.

Compare Time Skip, Not Important to This Episode Camp. Contrast Two Lines, No Waiting. Related to Rule of Perception.

Anime and Manga

 * Avoided in Dragonball Z, where there is a special chamber tha turns a day's training into a year's. The other characters only have to stand around for a few hours.
 * The two-and-a-half-year Time Skip in Naruto consisted mainly of a Training Montage for the three main characters: Naruto, Sasuke and Sakura. Akatsuki, the villains against Naruto, spent the 3 years doing little, if anything, to kidnap the boy while he was still weak.
 * Add that Jiraiya had spied on Akatsuki for nearly ten years but hadn't even told the Hidden Village it existed until he entered the story. Phones don't work in his waiting room?
 * On the other hand, most characters didn't sit down and wait for the time to pass. Every secondary character grew up, got new skills and ranked up; Akatsuki was busy not capturing the tailed beasts (leaving Naruto for last given the power level of his).
 * It's mentioned that they couldn't capture the Nine-tails until Last, due to some type of Power balance that has to be maintained in the Statue they are using, which is why they spent so much time just holding the Two-Tails instead of sealing it. Exactly what this Balance is, and how it works, is not revealed.
 * Turns out the demon statue that they seal the beasts in will shatter if they don't seal 'em in order from One-Tail to Nine-Tails.
 * Yakushi Kabuto, went into oblivion shortly after Orochimaru's last(?) death, only to return about 200 chapters later. Apparently, he had been quite busy in the waiting room.

Fan Works

 * Averted twice in With Strings Attached:
 * When three of the four get magic and Paul does not, he immediately goes out to try to learn how to cast spells. When he proves unable to, he spends an undefined amount of time in drunken jealousy and loneliness while the others obsessively play with their magic.
 * Later, when the four are impatiently waiting for the Fans to point them to the second piece of the Vasyn, commentary by John and Ringo informs the reader that Paul has spent all (literally all) his time practicing with his strength, while George, terrified that his ring will stick again, has barely used it and instead has been writing, meditating, and wandering around filming things with his Super-8 movie camera. What the other two did isn't mentioned outright, but it's implied that they pretty much did the same things they were doing during the first “layoff.”

Literature

 * This happens constantly in the Harry Potter series where, not only is Voldemort incapable of executing even his simplest plans in less than a school year, but the main characters will spend months just going to classes while doing nothing to advance the plot. Usually J.K. Rowling has an excuse, like giving them a clue that they don't know how to solve or research they need to do, but sometimes she doesn't bother.
 * Such as in Goblet of Fire, where she skips forward a couple of months and it would seem like Harry would have taken that time to figure out the secret of the egg he'd been given, but instead we find out that he hasn't even opened the egg in the intervening time. This was attributed to gross procrastination on Harry's part (despite the fact that he is well aware that his life may depend on finding the secret of the egg). The gross procrastination, though, could be attributed to the fact that he was fourteen.
 * Deathly Hallows is mostly composed of an on-stage waiting room. The protagonists are in way over their heads, and it shows. They spend weeks and months at a time accomplishing nothing, about nine months hiding out in total with only a single horcrux to show for it. Then they stumble back into the plot and get the other four (and two from another MacGuffin set entirely) in two days for the climax. Adding insult to injury are the secondary characters, who are entirely off-camera as they spend the same time living a thrilling life of growth, determination and death-defying heroism...
 * There was a lot of that throughout Harry Potter. Some characters look flat through being seen only briefly by him. Ginny had lots of bonding time with him at the Burrow and school, but that was largely unimportant to the plot so we only get a brief mention of it. The Tonks/Lupin relationship might have made more sense if Harry had seen more than just the weird extremes of it. The way we get Snape's backstory... it's a bit shoehorned.
 * Inverted in The Book of Amber by Roger Zelazny, where every character is doing something all the time. It is exciting, realistic and gets in the way of the story. Since it is told primarily from a single viewpoint, other characters turn into Mr. Exposition, relating the goings-on at length.
 * Possibly the original: Distance between Cairo and Jerusalem: About 280 miles. Span of Jewish exodus from Egypt to the Holy Land: 40 years. Velocity of exodus: about 1 mile every 50 days. There is a little Hand Wave about God punishing them because they wouldn't believe that the land existed, but we all know Moses just couldn't read a map. (Another theory holds that Moses, being male, refused to ask for directions. If Miriam and/or Zipporah had been in charge, the trip might have only taken a year.)
 * It may be justified in that they got to Canaan within a year (with an extra year off at Mt. Sinai) ticked off God and stayed on the outskirts of Canaan for 40 years, as God would let the Canaanites cream them if they tried to move in. Plus, have you ever tried to move 2 million people and all of their stuff that far?
 * One commentary says that there's a 38-year gap between the last verse of Numbers 19 and the first of chapter 20.
 * According to some literary critics of Old Testament, this is a result of merging two religious traditions into one (mostly) coherent story. (What The Other Wiki has to say about it.)
 * Similarly, the New Testament skips most of Jesus' early life, a fact that serves as a major point of discussion in the movie Dogma.
 * This is similarly the inspiration for Christopher Moore's novel Lamb the Gospel According To Biff.
 * Very, very Averted in the Dresden Files. There is usually anywhere between six months to a year between books, and Harry usually has made some sort of new magical device in the meantime. Not to mention a Noodle Incident or two...

Live Action TV

 * Happens over a short period in the Stargate Atlantis episode "Miller's Crossing". Dr McKay, Colonel Sheppard, and Ronon Dex have come to Earth to investigate the kidnapping of McKay's sister; at one point, Sheppard is following a paper trail, and Ronon excuses himself on the grounds that his badass fighting skills are useless at this point. While Sheppard investigates, Ronon goes to the cafeteria, where he is treated to an allegedly amusing story about requisition forms. He's incredibly relieved when Sheppard shows up.
 * Another Stargate version comes in the Stargate SG-1 episode 100 Days. Jack spends the titular hundred days on an alien planet, while the rest of the team looks for ways to save him. Apparently, they did nothing else of interest in those three-plus months. It would've been cool to see the team undertake a mission or two without him, as we know they must have.
 * Except Jack didn't have a hundred days because he was already "old". Only a few days passed, with the Phlebotinum Du Jour keeping him aging at an accelerated rate.
 * In the TV show Quantum Leap, there's a literal waiting room: in each episode, he switches places with a different person from the past, who then waits in the facility in the year 1999. (In many episodes, this is not always mentioned; but occasionally, especially in later seasons, the person will figure prominently in an episode. For example, in one episode, Dr. Ruth talks with Al in the waiting room about his love life.)

Theatre
"Lady in the Lake: Now we're halfway through Act II and I have nothing yet to do/I've been offstage for far too long, it's ages since I've had a song."
 * Humoriously poked fun at in the musical Spamalot with the Lady in the Lake's solo Whatever Happened to my Part

Video Games

 * This is pretty much canon in just about every single video game with a player-character-driven storyline. The heroes go off on whatever side-quest they want, while villains, hapless NPCs needing "urgent" help, even other player-character heroes (think the massive casts of many Final Fantasy games) sit back and twiddle their collective thumbs - although there are some notable exceptions.
 * Persona 3 and Persona 4 avert this in a very simple manner: you play through almost every day of the timeline in which they take place, with key events happening at various points along the calendar. It's made clear that everyone involved has their own lives and aren't just waiting on you to move the plot along.
 * In the final boss fight of Paper Mario, after, the focus turns to Peach and Twink. They have a small fight against Kammy Koopa, which helps Twink get the power to help power up the Star Beam to the Peach Beam. What are Mario and Bowser doing through all this? They've been glaring at each other for the last 5 minutes.
 * Subverted in Vandal Hearts. While the main character Ash and fellow warriors Grog and Sara have been stuck in a pocket dimension of displaced time for three days, several years have passed in the game world; during which time, the despotic Hel Spites has transformed the democracy into an evil empire and the other party members have started a resistance movement, three of them even getting captured in the process.

Web Comics

 * The parody-RPG webcomic ~Adventurers!~ has a literal waiting room which is seen from time to time.
 * In a similar vein, Real Life Comics had Greg and Tony crossing dimensions and ending up in what looked like a waiting room where "forgotten" characters are sitting around playing cards to pass the time. One of the characters (Lizzie, Greg's ex-girlfriend) even asks them if the author got sick of them, too.
 * Averted in the early arcs of Dubious Company. After the everyone gets, which forces focus on a larger cast, the creators have been good at justifying it. A simple handwave is that most of them are Lazy Bums. Just as often though, some of the characters will run off to do their own less interesting antics, allowing the story to focus on a few key characters' plot.

Western Animation

 * Avatar: The Last Airbender Lampshaded it in the episode "Sokka's Master" where Sokka spends a couple of days to learn swordsmanship, and it constantly cuts back to the other characters who are bored to tears and lying around in the dirt doing nothing, having been drained of all excitement with the removal of the team's lively comic relief. In the following episode, Aang goes on a journey into the Spirit World for a day to learn the backstory whilst the others sit around wondering if Aang has soiled himself.