Deadly Training Area

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.

A common plot involving one will be someone trapped inside on too hard a difficulty, sometimes caused by a Phlebotinum Breakdown or Holodeck Malfunction.

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.

Anime & Manga

 * In Naruto, Training Ground 44, also known as The Forest of Death, is probably the best example. Its 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 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...
 * 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.

Comics

 * 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 Chevalier Vampire 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).

Fan Fiction

 * The Danny Phantom fanfic Checkmate reveals that Vlad Masters has one of these inside his mansion. The highest setting very nearly kills Danny.
 * Similarly to the X-Men example, the Danger Room at Warriors' Mansion (as manifested by the Room of Requirement at Hogwarts) in Drunkard's Walk VIII. At one point main character Doug Sangnoir uses it to generate an urban wasteland populated with endless waves of fully-armed soldiers -- which he then fights off for an hour.

Film
"Rosa Klebb: Training is useful, but there is no substitute for experience. Morzeny: I agree. We use live targets as well."
 * There's a villainous example in From Russia with Love.


 * 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).
 * 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.

Literature

 * Dune has a swordfighting training machine that is quite deadly.
 * 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: 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.

Live Action TV

 * Holodecks in the Star Trek Verse - which are supposed to be primarily for training - are very prone to developing problems with the safety protocols, making them deadly.

Tabletop Games

 * The Champions supplement Champions II had rules for Danger Rooms. If the PCs wanted to, it was possible to set the level high enough to kill the person (or people) inside. If super villains invaded the base, one suggested tactic was to lure them into your Danger Room and turn it on full power.

Video Games

 * Jak and Daxter has a few of these in the later games. Jak 3 has sort of a gladiator pit with periodically rising, deadly lava, and guys that swing their pointy, deadly swords at Jak (who gets to wield a gun). In The Lost Frontier there's one gun course that has conveyor belts and platforms, surrounded by deadly pits.
 * 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 FFVIII 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.

Webcomics
"Pirate: What? NO! That would completly remove the point of a simulation. Samus: Well chalk up a rare victory for common sense."
 * 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.

Western Animation

 * In Danny Phantom, the titular 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 Avengers' training room in Avengers Earths Mightiest Heroes.

Real Life

 * 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.