In fiction, it's often necessary for characters, particularly those in the superhero genre, to train to fight extreme threats above and beyond what an ordinary person might face. So how does one train to fight supernatural or superhuman threats? By risking one's life in a training area or simulation, apparently.
The Deadly Training Area is a combination of obstacle course and live fire range where the hero must dodge a number of dangerous threats while achieving some objective. Common obstacles and weapons include solid objects that move rapidly to block them, giant blades or saws, laser cannons, simulated enemies (with varying amounts of firepower), and, in more realistic settings, guns.
More sophisticated examples will have difficulty levels, starting with "newbie" and ending with "holy crap we're all going to die!" In the most extreme cases, this training area will be just as dangerous or more dangerous than the hero's foes themselves.
Sometimes Fridge Logic kicks in regarding these training arenas. More often than not from a character asking the question of how risking death in training is better than risking death on the battlefield. Occasionally, these extreme measures are explained as emotional training, dire necessity, or simply the product of a mentor with a Darwinistic approach. Otherwise, if some characters in the setting have incredible regenerative or healing powers, it makes sense to make the training as dangerous as safely possible to better prepare the recruits: better break you spine in the training room and have it healed in five minutes tops, than skip the training room and break your spine on the battlefield with no magical healer available.
See also Improvised Training and Virtual Training Simulation. One of these will almost always be used in a Danger Room Cold Open. They are sometimes used in a Training Montage and/or Training from Hell. It is also sometimes the setting for an Unwinnable Training Simulation. This kind of training area can be a Simulated Urban Combat Area or a Fake Town, if it is intended to look like an actual urban area.
- In Bleach, when Ichigo is trying to regain them after Byakuya removes the Shinigami powers he got from Rukia, the first task is a case of a Deadly Training Person, rather than Area. He has to survive a punch from Ururu, while in his soul form.
- The Dungeon in ''Is It Wrong to Try to Pick Up Girls in a Dungeon?. Adventurers can pick up and learn skills outside, but can only really earn experience by fighting monsters and risking their lives inside.
- Training Ground 44, also known as The Forest of Death, is probably the best example. It's filled to the brim with very dangerous wildlife, and was the stage used for the second part of the Chunin Exams, where other teams where allowed to kill their competitors to complete the test. All the teams who entered even had to sign a waiver relieving the test proctor from all liability if they died.
- In Shippuden the hidden island used by Kumo to train its jinchuuriki used to be this as a result of its many large and aggressive fauna. The jinchuuriki B tracked down and beat up each of the animals until they respected him, so they don't bother anyone he likes.
- The Land of Accursed Springs, or Jusenkyo, in Ranma ½. Over a hundred deep ponds of various sizes litter a valley shrouded in fog, separated only by very thin strips of solid ground and with long bamboo poles rising from them (and, from the looks of these, they don't grow from the springs, but were put there by someone.) Martial artists travel to this valley to train by balancing atop the poles and jumping from one to another —presumably, while sparring with a partner. This is difficult enough in and of itself, but training there carries its own danger: each and every one of the ponds is cursed by whoever, or whatever, originally drowned in it. Now, falling into a spring curses the victim to physically change into the creature that drowned there, whether it was a frog, a bird, an old man, or a giant monster. So you really, really don't want to lose your balance while jumping from pole to pole
Two 'victims' got off easy, with one becoming a panda, and the other a girl.
- Throughout the series, individual characters will fashion their own mini-training sites deep in the mountains by preparing elaborate traps —collapsing logs, swinging boulders, pitfalls— to prepare for an upcoming fight.
- In Saint Seiya, Death Queen Island, the training ground for candidates for the Phoenix Saint Cloth, is an active volcanic site with deadly steam vents, open calderas, and endless plumes of black ash. And that's not even mentioning the training ground's taskmaster. Similarly, there are areas of Athena's Sanctuary (in Greece) that are built specifically as deathtrap-filled obstacle courses to weed out weak candidates, but it's hinted that these are a recent addition created by the current Pope.
- In Mission: Yozakura Family, the Yozakura's entire mansion is this. The AC emits nerve gas, every stairwell and room is booby trapped, the food is poisoned and there's a complex lock on the bathroom door. Even the alarm clocks are rigged to explode after ten seconds.
- The most famous example and possibly the Trope Maker/Codifier is the Danger Room from the X-Men series. The level of technology varies by the continuity, but it's usually capable of fully-fledged simulations.
- The other potential Trope Maker (although the Codifier is probably still X-Men) is from the Fantastic Four, who have a dangerous training area, as well.
- The training for vampire knights in Requiem Vampire Knight is carried out in Hell. Not only that, but in a specifically malevolent branch of Hell. Most of the apprentices don't get out with their deaths.
- In Judge Dredd, to best simulate the real street and combat situations all Mega-City One Judges face, only live ammunition and explosives are used on training courses at the Academy of Law. If a cadet survives making even the slightest mistake on the courses, they are immediately expelled from the Academy.
- The The Avengers also have a Danger Room-like training area.
- The Justice League of Europe had one of these, not unlike the Danger Room, in their embassy. On one occasion it got turned up to its maximum setting while two relatively low-powered members, the Flash and the Crimson Fox, were the only ones inside. Good times.
- Apparently built by accident by a D&D player in What's New? with Phil and Dixie. Inspired by the novel Dream Park, he'd built a homemade "dungeon" for his fellow-gamers ... one that incorporated actual land mines, flamethrowers, tigers and laser beams (the Green Berets liked it).
- In Detective Comics (Rebirth), the team's new base (called the Belfry) has one, known as the Mud Room. It uses excess Clayface matter to form solid opponent constructs.
- The shortly-lived Strikeforce: Morituri had an extremely potent version of this trope with Biowar Facility Alpha' (or 'The Garden', as it was more commonly known. Essentially a miniature version of a Death World with Everything Trying to Kill You (both organic and electronic/mechanical), the place was designed to act as a full-scale, real-time version of How Do I Shot Web? (which actually became Training from Hell, as two of the members of the very first Morituri team were killed in there and it became common for Morituri without active physical powers to be injured in the area). The kicker is that in-universe, the facility and the Strikeforce itself were directly inspired by the X-Men' & their 'Danger Room', as the creator's daughter was an 'X-Men' fan.
- In Superman story arc Crucible, the eponymous superhero academy has training facilities where the students fight virtual enemies and are put through simulated scenarios.
- Project Freelancer Phase One: Genesis gives its Super Soldier agents blanks and lockdown paint, but the sim troopers they face during training are issued live rounds.
- The Danny Phantom fanfic Checkmate reveals that Vlad Masters has one of these inside his mansion. The highest setting very nearly kills Danny.
- In Neither a Bird nor a Plane, it's Deku!, Tim Drake designed U.A.'s "Mud Room", a training area that combines Hard Light with the metamorphic properties of Clayface's biology that allows it to recreate nearly any environment imaginable for training purposes. The intensity of the programming means it's usually restricted to third-year students and teachers, but Mirio takes Izuku there for their spar and uses the room to imitate Centennial Park in Metropolis.
- Kung Fu Panda's training room is a rather impressive example, filled with all manner of wind-up or clockwork bludgeoning, stabbing, slicing, or burning devices.
- In How to Train Your Dragon, the Arena almost fits the bill. Though it is revisited several times, it never looks the same twice, as it is changed to suit the day's training. However dangerous, though, the intention is to avoid killing anyone, especially the Chief's son.
- There's a villainous example in From Russia with Love.
Rosa Klebb: Training is useful, but there is no substitute for experience.
Morzeny: I agree. We use live targets as well.
- X-Men Film Series:
- X-Men: The Last Stand: After the Distant Prologue, the X-Men are fighting an off-screen enemy (a Sentinel) in a burned-out urban wasteland. After Wolverine and Colossus take it down with a Fastball Special, the Danger Room is deactivated and the session ends.
- X-Men: Apocalypse: In the last scene, the young X-Men prepare to test their mettle against a few 1973-era Sentinels that have been repurposed for combat training.
- Spies Like Us. The protagonists have to go through this kind of training before being sent on their mission. It included having to hide in mud while live bullets were fired at them and being in a simulated plane crash (with the "plane" being dropped from 20 yards in the air).
- Rita's "training" room in Edge of Tomorrow where the hero receives combat training. Once he gets crippled by one of the attacking robots, Rita kills him, so he can start the session all over again.
- In El Conquistador, the Aztec empire has a deadly training site called Calmécac, that also is a High School.
- Dune has a swordfighting training machine that is quite deadly. Even pointlessly so, as noted in-universe with the injunction by teachers against letting it exceed a certain difficulty setting. While most people think this means humans simply can't survive at that level, the actual reason is that at that speed level its movements are sufficiently inhuman that fighting it only serves to mistrain the student for real swordplay. It's a rare aversion of the Training from Hell trope.
- In Thief of Time, Lobsang goes with History Monk Lu Tze to two potentially deadly training areas, one with large wooden balls, the other with walls studded with spikes.
- The past is viewed this way in Time Scout. Make a mistake and you end up dead very quickly. Make a bigger mistake and you die slowly. Make no mistakes and you still might die.
- The Dark Forest training in Warrior Cats. Unlike in real life, they train with claws unsheathed, and unlike in normal dreams, wounds sustained in the Dark Forest become real and physical: training can very easily result in a fatal injury. It's Training from Hell, both figuratively and literally, since the Dark Forest is feline Hell.
- In The Wheel of Time series, Rand al'Thor decides he needs to keep up his swordsmanship, so he hires the best swordsmen he can find to duel him with practice swords (bundles of wooden lathes)...six at a time. General Bashere lampshades it: no one trains with six men at a time, because odds are good that even with practice swords, somebody's going to accidentally do you in, and without Rand alive and kicking the world is screwed.
- The infamous Carrera's Legions has the aforementioned Legions suffer 1.5% casualties before any of their recruits hear a shot fired in anger thanks to this trope, some of which is intentional but a fair bit is a result of sheer carelessness. (And yes, these are supposed to be the good guys.)
- Jak and Daxter has a few of these in the later games.
- Portal has a live fire military training course that, according to GLaDOS was intended for military androids. It features a series of turrets that will kill you for purely being in their line of sight. This trope is slightly subverted by the tendency of the turrets to shut down after simply being knocked over, and the fact that you have a weapon that shoots trans-dimensional portals.
- Balamb Garden from Final Fantasy VIII had a sort of Greenhouse-like training area where you could fight against the local variety of voracious flora. Occasionally, a Tyrannosaurus rex would eat you.
- One of the more popular ways to train soldiers in Dwarf Fortress is a "danger room", with the whole room covered in spike traps hooked up to a lever set to repeat. Of course, since the spikes are just sharpened wooden sticks and the dwarves are covered in armour, it's not actually that dangerous... except for babies, if they're being carried around by a mother who goes to train in the danger room.
- In the Fallout 3 DLC Operation: Anchorage, the Anchorage Reclamation VR simulation has its failsafes disabled, so if the user dies in the simulation, they die for real.
- In Daikatana, the final level requires you to make your way through a SEAL Training Facility in 2030 AD. Apparently, SEAL training in 2030 AD involves jumping across moving platforms over instant-death electrified floors, dodging massive crushers, and swimming through a shark tank.
- The Black Mesa Hazard Course in Half-Life and its counterparts in Opposing Force and Blue Shift are a minor example; nothing can kill you instantly, but several obstacles do actually sap your health, some of which are unavoidable.
- In Metroid: Third Derivative, a now defunct fancomic that was hosted on Bob and George, Samus asks if this is the case with a simulation and the Space Pirate explaining it to her responds.
Pirate: What? NO! That would completly remove the point of a simulation.Samus: Well chalk up a rare victory for common sense.
- The Avengers' training room in The Avengers: Earth's Mightiest Heroes!.
- In Danny Phantom, the title character has set one of these up in his parent's basement. Despite being jury-rigged, it includes moving walls, laser cannons, and descending loops to practice flying.
- The Powerpuff Girls. The Professor designs a holographic training room in which the girls may hone their ultra-super-powers by beating up virtual enemies. The simulation has a numerical difficulty setting (from one to ten) but the Professor insists they stick to the lower numbers for safety's sake. The problem arises when Bubbles worries that being a Girly Girl means she's soft. A few jeers from enemies make her doubt her strength and fear that she's not as heroic as her sisters. To prove she's hardcore, she enters the simulator solo and turns the difficulty dial literally Up to Eleven.
- In Steven Universe Steven and Connie regularly practice in an ancient Gem arena. Its location, suspended in the clouds far above the Earth's surface, eliminates distractions and collateral damage. The kids' training is guided and supervised by Pearl, whose attentiveness protects them from most risks. However when Pearl is absent or incapacitated the arena is not inherently safe, especially due to the risk of falling.
- The Hero's Forge in Trollhunters.
- Infantry training in several countries has traditionally involved troops crawling along the ground below live machine gun fire or training in areas seeded with an unknown amount of unexploded ordinance collected over decades of use.
- The reason for this, as well as the more general form of life fire training is that soldiers do far worse with live fire than with blanks. This is due to the fact that without the fear of death in training, they are completely unprepared for actual combat. Obviously the more extreme versions of this in fiction are unrealistic in that killing your people is wasteful.
- The presence of live ordnance also ensures troops pay more attention to the training itself. A person naturally tends to be more aware of proper weapon handling when they know it's loaded with live rounds.
- Special forces operators and SWAT teams train in "kill houses" to practice close quarters battle. Taking the lead from the SAS, elite units always use live rounds in training.
- An accidental one shortly after World War II: US Army and Navy personnel were trained to deal with encountering tactical nuclear weapons, using real tactical nuclear weapons. They were far enough out not to be injured by the blast, but charging directly into the mushroom cloud exposed them to a great deal of radiation, giving many of them radiation sickness and/or cancer.
- By definition, pilots have to train (outside simulators) in the same environment with the same hazards as their normal working conditions. This is especially true for pilots who have to fly in inherently hazardous conditions, such as off aircraft carriers.
- Part of firefighter training is to go into structures with actual smoke and heat, that will seriously harm or kill you if you screw up, your equipment malfunctions, or you don't prepare properly. The only differences between the training and a real fire is that you don't have to worry about a structure collapse and any bodies you find are dummies.