Avengers Assemble

"The Avengers gotta get to the assembly."

—Xander, Buffy the Vampire Slayer

A Dream Team is needed for The Con or The Caper. Each teammember is contacted in a short scene revealing their specialty. This sequence culminates with all the members being in the same room together. c.f. Oceans Eleven, Mission Impossible.

Compare A-Team Montage, Intro Dump, Lock and Load Montage, Putting the Band Back Together, Everyone Meets Everyone.

Not to be confused with a Web Original parody video series of the same name, or the UK title of The Avengers.

No real life examples, please; Real Life does not have montages.

Examples of Avengers Assemble include:

Anime and Manga

The manga based on the Galaxy Angel gameverse begins with one of these, but (since there are almost no battles) the montage is more about the girls' individual quirks.
Spoofed in the final episode of Irresponsible Captain Tylor when Yamamoto calls back the Soyokaze's crew from their absolutely ridiculous journeys to find themselves (such as Lt. Andressen's stint as a nude life-drawing model).
In the Fullmetal Alchemist manga, Roy's group has a scene where each of them is shown displaying what their specialty is, culminating in everyone being on board with the long hard slog that is being the rebel group in a corrupt military.
Voltron, (and, obviously, its original incarnation, GoLion) both Lions and Vehicle Force versions, practically defines this trope, particularly Lion which showed each Lion emerging from its specific hiding place to enter battle. The hiding places reflected the powers and abilities of their respective Lions (Red emerging from a Volcano, Blue from a lake etc.) While it is true that the Voltron team members themselves are usually in the same place when this happens, they must immediately separate to get to their Lion or Vehicle before coming together again. It's a little different in Vehicle Voltron as the main team is separated into smaller teams that are always together in getting to their vehicles.

Comic Books

Named for the rallying cry of Marvel Universe's most prominent superhero team. On those occasions where the roster changes, The Avengers tend to assemble in a more haphazard fashion.
In Fantastic Four #1, Reed Richards first summons the group together by creating a huge cloud above Manhattan that bears the words "Fantastic Four" before morphing into a "4." The other three show off their abilities because it's symbolic or something: The Invisible Girl vanishes in public, and being quite a ways away has to take a cab while invisible. (This actually works, though it scares the pants off the driver.) The Thing ditches his disguise, causing traffic accidents and drawing fire from the NYPD before he opts for the sewers. The Human Torch flames inside the car he was fixing, melting it, and while in flight is intercepted by jet fighters and ultimately a nuclear missile—still over Manhattan—requiring Reed to use his stretchiness to save the day.
This occurs after the team has been assembled in the first issue of the next-to-most-recent Suicide Squad, where the Terrible Trio Injustice League is put to work doing dangerous missions for the government. As they land on the island their mission is to take place on, it becomes clear what everyone's role is quickly: Big Sir hauls a gigantic watercraft on his back with ease, Clock King calculates the exact amount of time the task will take, Major Disaster barks orders and coordinates the team, Multi-Man frets about what his ever-changing powers are right now, and Cluemaster proves to be astonishingly perceptive.
The Teen Titans in the comic book had an Avengers Assemble (or rather, Titans Together) gathering. When the Justice League refused to help Raven with her demon father, thinking it a trap, she appeared in the dreams of various teen heroes and rallied them to help her fight Trigon. Starfire just so happened to be escaping to Earth from her captors in time to help them.
Marvel: Contest of Champions does this with pretty much every living hero who existed at the time in the Marvel Universe, plus a few new ones they spotted on the way. Though instead of a call, they were teleported (without choice) by a weird red light.
Showed up in a few issues of G.I. Joe, notably issue #2.
Appeared in Issue #28 of The Brave and the Bold, the debut of the Justice League of America, where Aquaman learns of a monster called Starro and uses his belt to signal the rest of the League for an emergency meeting. Most of the remaining Big Seven responds, as is typical of the trope (Wonder Woman breaks a date with Steve Trevor, Green Lantern sets his test plane on autopilot, The Flash takes care of a tornado, and the Martian Manhunter had just received vacation time for his human guise when he got the call), though Superman and Batman had commitments too important for them to abandon (Superman is fighting off a meteor storm about to enter the planet's atmosphere, and Batman is overwhelmed by a crime wave in Gotham City).
The Defenders in most incarnations are loners, so many a Defenders story begins with someone, often Doctor Strange, visiting each potential member in his or her home turf and issuing the Call to Adventure.

Film

Armageddon has an awesome one. Bruce Willis needs to assemble his Magnificent Team of Ragtag Roughnecks, but "once they get off the rig, they scatter." The ensuing montage shows FBI agents tracking each member to his natural habitat:
- Michael Clarke Duncan is on a motorcycle in South Dakota.
- Ken Hudson Campbell is in a tattoo parlor with his mama.
- Steve Buscemi is sleazing on girls in New Orleans.
- Owen Wilson is on his horse ranch in Texas.
- Will Patton is at Caesar's Palace playing craps.
- Ben Affleck is running his own oil field somewhere on the Middle of Nowhere Street.
  - Just about everyone looks up from whatever they're doing to see soldiers and resigns themselves to the inevitable. Affleck is so smug at Willis swallowing his pride to come see him personally that he comes without(much) complaint. Michael Clarke Duncan starts up a Chase Scene, yelling "COME AND GET PAPA BEAR!"
Tweaked a bit in Star Trek III the Search For Spock. The crew needs no introduction; nevertheless, following the scene in which Kirk decides he's going to disobey Starfleet and steal the Enterprise, we get a Mission Impossible-esque montage of each crew member doing their part to execute the heist. Each person's part is related to their skill. Kirk breaks out McCoy, Scotty sabotages the Excelsior's engines, Sulu kicks a guard's butt, and Uhura famously shows a cadet "some adventure".
Seven Samurai may be the Trope Maker. The leader of the eponymous warriors is recruited by some villagers to protect a village from bandits, and he goes about convincing six others to join him.
- Its American adaptation, The Magnificent Seven, has Steve McQueen's character Vin hold up fingers to count the members of their group when each new man joins.
- This was spoofed in the first season of Blackadder, and in Deep Space Nine's The Magnificent Ferengi.
Spoofed in the film Return Of The Killer Tomatoes; each new team member is revealed to have a stranger special skill than the last.
- This was a rehash of the sequence in the first film, Attack of the Killer Tomatoes. It was explained there that the team was being set up to fail.
Most of the cast of the film version of The League of Extraordinary Gentlemen are introduced in this fashion in one scene. Extra scenes are needed to introduce Jekyll/Hyde, Sawyer, and Gray.
In The Usual Suspects, it's done through the team's arrests.
In The Bourne Identity, Treadstone headquarters orders all their field agents to go active. Cue the montage of each agent in the middle of some civilian activity, and dropping it upon receiving instructions from HQ.
The Guns of Navarone: The officers planning the operation have a Mission Impossible-style set of photographs of the soldiers who will be taking part, and list their specialties (lucky, genius with explosives, mechanical expert, born killer etc.)
This happens in Eddie and the Cruisers 2: Eddie Lives!, while Eddie is assembling a new band; We get to see each prospective member play to get a feel for their, you know, style. But, like everything else in the movie, it's retarded; Among other things, Eddie picks a repressed concert pianist to play keyboard in his blues rock band, and also gives a spot to a guy he absolutely hates for no real reason.
Anchorman: The Legend of Ron Burgundy:

"NEEEEEEEWWWWWWWSSSSSSSSS TEEEEEAAAAAAAMMMM! ASSEMBLE!"
"Ron, we were here literally the entire time you were."

The original script for Monty Python and the Holy Grail had this as a sequence, but it was shortened greatly in the final film, probably due to budget constraints. Arthur finds Galahad building a chicken coop for an elderly couple; there were (would have been?) similar scenes for each of the knights.
Stanley Kubrick's The Killing has a couple scenes along these lines; although the main heist team is already assembled, ringleader Johnny Clay is shown recruiting sniper Nikkie Arcane (Timothy Carey) and Maurice, a chess-playing wrestler.
The Sting showed Paul Newman reassemble his old gang of cons in a wordless montage set to Scott Joplin's "Pineapple Rag" where he finds and signals to each by flicking the side of his nose.
The 1971 version of The Andromeda Strain uses this trope for the scientists near the beginning, although it takes a while to get them in the same room because two of the scientists take a detour to investigate the plagued town.
Extreme Prejudice (1987) begins with the special forces team arriving at an airport in civilian clothes, interspaced with shots of each man's military photo ID and a statement of how they 'died' in action or from training accidents.
The Marvel Cinematic Universe—the entire Marvel Cinematic Universe—has been a giant one of these, introducing every character in their own film (or films) and having Nick Fury show up in each with the recruitment speech, all culminating in the moment when everyone from Wakanda to wizards shows up to fight Thanos in Avengers: Endgame -- at which point Captain America finally says the line for the first (and probably only) time. "Some Assembly Required" indeed.

Literature

Played with in The Three Musketeers. Losing his companions en route of a dangerous mission, D'Artagnan must spend three chapters collecting them back up and extricating them from the situations their particular personality quirks have gotten them into.
In William Gibson's Neuromancer, Armitage gathers a team of specialists for his mission: to unite the artificial-intelligence entities Wintermute and Neuromancer.

Live-Action TV

Mission Impossible had an interesting take on this, at least in the earlier seasons: The Captain would take out a dossier full of potential team members, many of them shown engaging in activities relevant to their particular skills, and we would watch him picking out the team he wanted—usually the same core members, but with an occasional addition.
The premiere of Hustle spent about ten minutes doing this for the four team members, and was narrated by a policeman explaining their enemy to a colleague. The footage from this sequence was used in quite a few TV spots.
Power Rangers Lightspeed Rescue, Power Rangers Operation Overdrive, and Power Rangers Samurai open this way.
- As does Samurai's source material, Samurai Sentai Shinkenger.
A great example begins the second episode of Hoolywood East TV's New Kids on the Rock.
Leverage does this twice. Once, in the second episode, it showed the team members in the midst of various solo jobs, dropping what they were doing (Eliot had a gun pointed at him and took the guy out, Parker was hanging from a ceiling during a heist, Sophie is attempting to get a job on a soap commerical) to answer their phones.
The failed pilot for a parody of Mission Impossible, Inside O.U.T. had a such a sequence for members of the Office of Unusual Tasks. The most memorable was the agent whose cover was as a civilian flying instructor. When he got the call, he told his student something along the lines of, "You're going to solo a bit ahead of schedule," and bailed out of the plane.
The Star Trek: Deep Space Nine episode "The Magnificent Ferengi", complete with holding up fingers as each new member joins the team (referencing The Magnificent Seven).
The Doctor Who episode "A Good Man Goes to War" has a sequence of the Doctor rounding up his allies for a mission. There are quick scenes of them all going about their business (nursing soldiers on a battlefield, KILLING JACK THE RIPPER, etc.), only to come home and discover a big blue box on their doorstep. "The second episode of the same season" begins with 3 of the main characters being killed one-by-one by another character. Only afterwards do we find out this was all an elaborate plan to gather the team together.
Blackadder: The episode "The Black Seal" parodies the sequence from The Magnificent Seven when Prince Edmund rounds up the most evil men in the kingdom.
The West Wing does this in the very first episode. Toby, C.J., Josh and Sam each appears in a short character-establishing scene, receiving a text message at the end that says, "POTUS in a bicycle accident." The final scene reveals that POTUS stands for "President of the United States," and that the characters we've just seen all work for him.
Parodied in Scrubs with Ted's band the Worthless Peons. Whenever he yells "Peons assemble!" the other members of the band sprint in from all directions and stand with him. Ted notes that they have to perpetually be within earshot so that they can assemble at the drop of a hat.

Video Games

The introduction videos in the Sly Cooper video games have these, such as Bently: The Brains, Murray: The Brawn and so forth.
- The entire third game is spent assembling a team for a difficult break-in; it is told as a How We Got Here.
An ad for Spyro: A Hero's Tail does this.
A heroic, galactic-scale Big Damn Heroes version of this trope provides much of the plot for Mass Effect 2, with The Con or The Caper in this case being a Suicide Mission through a relay from whom no-one has returned against an unknown alien threat. Lovely.
- Most of the game is actually an extended Avengers Assemble sequence, with each of ten (or twelve with DLC) characters getting a recruitment mission and a loyalty mission that play to their specialties (e.g. Garrus the Friendly Sniper has a recruitment mission involving holding a fortified position and a loyalty mission that involves lots of foes that are particularly vulnerable to his tech powers, Tali's recruitment and loyalty missions both involve fighting Geth that are particularly vulnerable to her epic hacking skills, Mordin's recruitment and loyalty missions involve fighting Vorcha and Krogan that fall easily to massed Incinerate powers, etc.).

Western Animation

The Animated Series M.A.S.K. did this. Once an Episode, a computer would review the specifics of the upcoming mission and select the appropriate operatives for the job based on their helmets (Masks) which gave them their powers, their natural skill sets, and their vehicles.
In the Teen Titans episode "Calling All Titans," Robin contacts every single member—and there are about thirty! -- to let them know to stand by for further instructions.
The first episode of Transformers: Robots in Disguise has the Autobots issue a battle protocol, and Optimus Prime requests that the Autobot Brothers be sent in to stop the Predacons. T-AI goes over the Autobot Brothers' abilities and personalities.
The teaser for Avengers Earths Mightiest Heroes shows the trope used along with the Trope Namer: When Iron Man calls "Avengers Assemble!" and activates a signal, each Avenger is doing something until hearing the signal; Captain America is training, Thor is meditating on the sky, and Giant-Man and the Wasp are making a son (they are building Ultron, you dirty-minded!)
- In the eighth episode of the show, we learn that the Avengers order each other to gather with communicators that double as ID cards.
- Lampshaded in "Living Legend".

Iron Man: Avengers, Assemble!
Ant Man: We're all right here.
Iron Man: ...

- And Inverted in "This Hostage Earth" when they split up to investigate the different anomalies.

Iron Man: Avengers Assemble! ...Well, actually, Avengers Disassemble!

"THUNDERCATS, HO!" and a beacon in the sky would bring all of the Thundercats running to Lion-o, whatever they were doing at the time.
A villainous example appears in the first episode of He Man and The Masters of The Universe, when Skeletor magically summons his henchmen.
The short The Justice Friends in Dexter's Laboratory does this every time in the intro, and when Major Glory calls on his teammates. Justice Friends, Assssssembllllllle!
Jackie Chan Adventures does this whenever Jade calls together the J-Team, but it's only a two person montage since Viper and El Toro are the only ones not in Uncle's shop/Section 13 at the time. And of course, when they arrive Jackie tells them that Jade wasn't supposed to have called them and they should just go home.