Every team has the trainee, someone who isn't just ready for field deployment. Or perhaps the protective nature of the experienced members compels them to keep the trainee out of serious battles for their own safety.
But then the bad guys take their evil master plan into overdrive and suddenly the team is massively outnumbered or outclassed in terms of power.
Cue everyone gearing up for a serious battle, getting the heavy weapons and the trainee assuming they're just going to be slated to the same old desk job when they are stopped and told to gear up with the rest of the team. Because the situation is that dire that everyone with combat ability has to go, even they are inexperienced, incapable and have been voted most likely to be more dangerous to themselves or their team then the enemies they are fighting.
Expect the phrase "Not this time" to be commonly used to halt the trainee as they attempt to depart to take up their regular duties.
This is a common plot device with Anime and Video Games, since both frequently have stories about the personal growth of young characters.
See Closest Thing We Got for a related trope.
- Attack on Titan: The series' initial focus is on a team of newly minted graduates repelling a sudden invasion of titans. Eren, the main character, gets eaten right off the bat...but thanks to the series' Applied Phlebotinum he survives, and the plot marches on.
- Mobile Suit Gundam:
- The series begins with one of these, as the attack on Side 7 by Zeon's Zaku II Mobile Suits takes the Federation forces completely by surprise and forces cadets into action alongside other soldiers (in particular, cadet Ryu Jose is at Captain Paolo Cassius' side when the latter personally mans an anti-aircraft gun to try to repel the attack, and also drags the captain to safety when an explosion wounds him). By the time the attack is over, it's mostly the cadets who are left alive, forcing them to conscript several civilians in order to make up their numbers and crew the White Base while it tries to get to safety. The few surviving soldiers act as advisors due to being incapacitated by wounds (and in the case of Captain Cassius, slowly dying of his wounds).
- During the climatic battle of A Baoa Qu, Kycillia Zabi notices that Zeon's Rick Doms and new Gelgoog Mobile Suits are moving very sluggishly compared to the Earth Federation's GM and Ball units, and asks Zeon officer Twanning about it. He explains that the Rick Doms and Gelgoogs are being mostly piloted by trainees, assuring her that they're fully trained. A sceptical Kycillia notes that while she believes him in that the trainees are trained, her question is whether or not they'll actually be effective. Ancillary material like the Gihren's Greed series and other manga will make it clear that no, no they were not, and the major reason that trainee pilots were being sent into battle with cutting edge, difficult to pilot machines like the Gelgoog (which, it has to be mentioned, were at least as powerful as the titular Gundam) is because that was pretty much all Zeon had left with most of their veteran pilots (along with many aces) being killed off throughout the war.
- Mobile Suit Gundam MS IGLOO: Zeon commander Cuspen is disgusted when he's tasked with preparing a defense of the Zeon motherland, only to learn that the "new superweapon" and "elite unit" he'd been promised turned out to be a slapdash Mobile Pod called the Oggu (basically a cylinder with a gun on one end and a missile launcher on the other) as well as cadets fresh out of military school with a mere 250 hours of flight time.
- Mobile Suit Gundam:
- Fathom: Kiani has recently reunited with her younger sister and they are under frequent attacks by Admiral Maylander, who believes them to be enemies of America. Kiani keeps sending Anika off to guard the village while she fights, then when Admiral Mayhab brings out his latest weapon, hydrophagic engineered soldiers, Kiani says that "both of them are needed" to fight this new threat.
- Pacific Rim: Two examples, one offscreen in lore:
- When the Jaeger neural interface was first tested and it was discovered a two pilot system was required, the scientist who created it volunteered to be the second pilot alongside the actual trained soldier. Possibly justified because all prior test pilots had been killed due to the strain of using the interface alone.
- When Leatherback disabled Striker Eureka with it's EMP, Mako has to go into battle, despite being completely failed to drift properly on her first attempt and nearly shooting up the base by subconsciously activating Gypsy Danger's plasma cannon.
- Star Trek (2009): In the first Star Trek reboot film, which is set around 10 years before Star Trek: The Original Series, a plucky band of cadets get summoned to an attack on Vulcan by a vessel from the future. Battles ensue and by the end of the movie, they all earn battlefield promotions akin to their positions in the main timeline.
- 27 years before that film, the experienced officers of the Enterprise took a bunch of cadets on a simple training cruise, interrupted by a distress signal, in a small film called Star Trek II: The Wrath of Khan.
- The climax of the first Police Academy involves a riot breaking out across the city and all the police academy trainees have to be deployed to bolster the short-staffed police force.
- Just prior to the Battle of Helms Deep in The Lord of the Rings: The Two Towers, weapons and armor are handed out to both old men and boys that are barely twelve, as they prepare to defend the fortress against an army of thousands of Uruk-Hai.
- Ciaphas Cain:
- One of Cain's first tasks is to handle two regiments hastily cobbled together from the remnants of two very different ones (the all-male 301st specializing in planetary assaults and the all-female 296th in logistics) after they both took severe losses to the Tyranids. While not exactly trainees (surviving Tyranid attacks tends to make one a badass by default), the 301st resent the 296th's relative lack of combat experience but still being in charge (Kasteen had three days' seniority over Broklaw, which was enough to get her a promotion to colonel). Cain deals with the Cultural Posturing (much of it gender-based) by reforming the regiment as the Valhallan 597th (a combination of their numbers) and reforming the squads to be mixed-gender, instituting rewards for good behavior rather than punishment for bad as most commissars would have done, and under him it become one of the Imperium's best, one of their quartermasters eventually becoming the Imperium's first Lady General.
- Cain repeatedly snarks at the Planetary Defense Forces being utterly terrible at their jobs (descriptions along the lines of "holding their lasguns as if they'd just discovered which end was the front" show up a lot) or being meatshields until the real Guardsmen show up. Justified in that PDF are basically anything rejected by the Guard tithes, and on most planets their only real purpose is putting down civilian uprisings.
- In the second season of Arrested Development, Lucille volunteers Buster for the army after being asked if she would send one of her children to war by a reporter. (At first implied to be Michael Moore, but later revealed to be a lookalike for a segment on a late-night talk show.) Buster does go through with it, but only because he assumes he'll be rejected for his various shortcomings. However, he underestimates their need for recruits and is accepted.
- Lab Rats: When the team discovers Krane has manufactured an army of bionic soldiers that is too many for even them to fight, they return to the Lab and report that it's time for everyone to mobilize. Leo anticipates that he will be slated for Mission Specialist Desk Duty, only to be stopped by Donald and told this time, he's going with the team.
- Star Trek: Deep Space Nine:
- Nog enlists in Starfleet during Season 4. He gets a field commission during the Dominion War after serving on the Defiant for just months.
- The crew of the Valiant were cadets, albeit members of the elite "Red Squad" training group. They also only wind up serving as they do due to the pride of their acting captain after the real officers were killed, with nothing actually stopping them from returning to Federation space.
- Early in Ace Combat 5: The Unsung War, all but one experienced pilot on Sand Island are wiped out in a surprise attack by an unknown aggressor, leaving only the trainees on active duty. One of them is the Featureless Protagonist, who is joined by three others (one of whom is not even out of his basic flight training yet) on desperate missions to defend the air base—and the four of them eventually become one of the most decorated units of the Osean Air Force. Osea later attempts to pull this off intentionally, transferring all trainees from a nearby Heierlack Base to Sand Island, but they all get wiped out in the very next real battle.
- The plot of Metal Slug is about this, where 2 young trainees of the Peregrine Falcon mercenaries had to be dispatched because the Rebel Army struck during their training session.
- Overwatch Uprising event mode is a playable version of Tracer's first mission (along with Mercy, Torbjorn and Reinhart filling the rest of the playable character slots); liberating King's Row (which is either her home, or very nearby) from an Omnic terrorist group. Downplayed, as she was explicitly said to be just about qualified for active duty, and was deliberately sent in because she convinced Morrison to intervene despite the British government's wishes (and perhaps because she would have plausible deniability for being there anyway).
- In some of the games from the Gihren's Greed series, if the player is playing as the Earth Federation should the war drag on a suggestion will be made to speed up training so more pilots can be sent into battle. This unlocks Kou Uraki and Chuck Keith as useable characters. It should be pointed out that both characters are trainees in the year 0083, meaning that if an Earth Federation player is using them in 0079 they're almost s. On the Zeon side, a similar option can be made which likewise introduces rookie pilots like Bernard Wiseman.
- In Shin Gihren's Greed, when playing as Amuro Ray he is treated as though he's part of one of these, as he was a civilian only a few weeks ago who was forced to pilot the Gundam out of sheer necessity and only joined the Earth Federation military as an alternative to being imprisoned for his knowledge of military secrets. The officer who welcomes Amuro to his new posting at Madras informs him that while he's only a trainee as far as the Federation military is concerned, the officer himself expects great things of someone who managed to kill two Zakus in his first ever battle.
- Star Trek Online: The Federation player backstory is this, as the player's Canon Sue with their plucky band of cadets manage to take out numerous Klingons and Borg in their outdated Miranda-class starship before everyone gets a battlefield promotion.
- In XCOM 2 if the Avenger is shot down you will at first deploy your regular squad, but over time Bradford will send the rest of your soldiers into battle, eventually even sending out squaddies and rookies. Due to the massive amount of aliens on these missions, most of them will either die or take multiple levels in badass.
- One-Punch Man: This technically happens to Saitama as within the Heroes Association, Saitama is a low ranked fresh graduate who takes on S-level missions exclusively. Of course, Saitama is also extremely underrated within the organization and has a wealth of unrecognized prior victories.
- Stand Still, Stay Silent: Reynir's technical status is Little Stowaway, but he's teaching himself to use runic magic over the course of the story. Within a few hours of him managing to make his first working rune, the crew has to face a massive troll Zerg Rush that is considered bad enough to require maximum resource deployment. During preparations, Lalli, the only of the two crew's mages that is going to actually fight, has Reynir draw his rune on the defense perimeter's floor as an extra measure against the trolls.
- During the final stages of World War II, Japan's increasingly desperate measures included getting every citizen to fight the invaders, including women and children. Same story with Germany, which mobilized squads of underage boys to hold off the Allied advance into Berlin.
- There were multiple battles in the The American Civil War that involved cadets being sent into battle alongside trained soldiers.