Obviously, to build something this high on the Sliding Scale of Villain Threat, he needs a ton of Unobtainium or cosmic keystones to make it work, which the villain will have to steal in a string of smaller crimes that will draw the hero's attention to him long before it is complete.
You may notice that in story terms, a Doomsday Device is one big MacGuffin powered by several smaller MacGuffins. Having one in a story is essentially giving a villain a "Collect The Plot Coupon" quest and having the hero stop them.
The nature of the Doomsday Device does not matter unless it is actually activated. It rarely is, outside of deconstructions or backstories of ruined worlds. It can essentially do anything, as long as the end result is global or near-global destruction. An Earthshattering Kaboom, an army of Nanomachines, a Zombie Apocalypse, Weather Control, Frickin' Laser Beams, or a particularly large Horde of Alien Locusts. It's the scale that makes it a Doomsday Device. Typically, a villain will construct one that best reflects his personality.
Also keep in mind, that the entire point of a Doomsday Device is lost... if you keep it a secret, nein?
Anime and Manga
- Dr. Hell from Mazinger Z loves built them (and in the manga of Gosaku Ota, he stated he was already working on them when he working for Hitler, but he kept them for himself. He also claimed if he would have revealed all his inventions, Germany would have won the war).
- Takahashi-Sensei wrote a short story in the early 1970's (with many of the plot elements later ending up in Urusei Yatsura). In this tale, three alien races all decide to blow up Earth for their own reasons and launch tiny planet-busters, all of which end up in the same person. Then they discover each other and compare notes. The Horrible Truth: Their planet-busters all work by different principles, and if they go off together in one person, they will literally destroy the universe. So the aliens all set about making sure nothing bad happens to the person with the Doomsday Devices inside him, resulting in an age of galactic peace and unity.
- One of the Doraemon movies deal with the logical outcome of an ancient Dead Hand (see Real Life section below) system outlives its creator civilization. Long time ago, there were not one but two Atlantis-like undersea civilization: the aptly-named Atlantis, and Mu. They went to war with each others, and it was either Mu won, or Atlantis collapsed on its own. The Dead Hand system of Atlantis, called Poseidon, is located in Bermuda Triangle and is still fully functional. Its activation will render the world "unhabitable even for the smallest and most resilient insects", and the increase of severe undersea volcanic activity will be interpreted by Poseidon as "the Mu are attacking our last line of defense". So the Mu people beg Doraemon and friends in a (suicide!) mission to destroy the core of Poseidon with Doraemon's future gadgets.
- Meanwhile has a booth called a Killitron which, at the press of a button, will kill every human outside. This, combined with the weird intricacies of quantum mechanics, allows it to be used for practical purposes, like making ice-cream.
- Doctor Octopus likes to build Atomic Doomsday Devices.
- Magneto's usually consist of trying to alter the rotation of the Earth or a friggin' huge meteor.
- In The DCU series called L.E.G.I.O.N., a horrific conflict is neutralized with the application of a potential destructive device. Anyone gets uppity, the device goes off and everyone suffers. Seemingly... the device is just a bunch of shiny bits. It does nothing.
- In The Umbrella Academy, Vanya/The White Violin, is both a Musical Assassin and a Doomsday Device, rolled into one.
- Wandering Star. President Andrews destroys Earth by secretly activating the Weapon Armageddon, an old doomsday device believed to have been disarmed, to prevent Earth from being enslaved by the Bono Kiro.
Films -- Live-Action
- The Death Star from Star Wars is an iconic example.
- Doctor Strangelove features an automatic Doomsday Device that will fire if Russia is hit with a bomb. The rest of the movie revolves around stopping the bombing some stupid general ordered. They don't.
- Truth in Television: http://en.wikipedia.org/wiki/Dead_Hand_(nuclear_war)
- The cobalt bomb at the end of Beneath the Planet of the Apes.
- Dr. Soren's trilithium probe in Star Trek Generations. It stops all fusion within a star, causing it to collapse and generate a shockwave that destroys all planets in the solar system.
- From Frickin' Laser Beams in space powered by diamonds to stolen nuclear submarines to life-ending biological weapons, James Bond villains have made this trope their raison d'etre.
- In the recent Mark Gatiss adaptation of The First Men in the Moon Professor Cavor suggests that his Anti Gravity paste Cavorite could be used as one. A sheet of Cavorite pasted on the ground would make the air above it weightless, causing it to shoot out into outer space. More air would rush in to fill the vacuum until the entire atmosphere was gone. Cavor ultimately uses this idea to exterminate the Selenites (and himself) before they can force him to help them conquer the Earth.
- 'The Doomsday Device' starts with one of those, which is an excuse to launch seven people into space (and a bad movie).
- Johan Schmidt's Valkyrie Amerikabomber from Captain America: The First Avenger also counts. It carried a large arsenal of city-busting WMD's and had the ability to traverse the Pacific in a few hours, at speeds and altitudes that would make it dificult to intercept. It was also powered by the Cosmic Cube. Its intended use was to destroy most of the world's major cities, starting with New York.
- A short story by Edmund Cooper has teams of American, Russian and British scientists all building incredibly elaborate Doomsday Devices that will destroy the world completely if anyone tries to use nuclear weapons or invade their countries at all. This ends up causing world peace; in a subversion the scientists reveal to each other at the end that none of the machines actually work, but are just impressive collections of cables, strange chrome things and flashing lights, with the exception of the Russian doomsday device, which will blow up anyone who tries to use it..
- Doctor Impossible's current scheme in Soon I Will Be Invincible—most of his part of the story covers the "Collect The Plot Coupon" quest.
- The Mouse That Roared (first a book then later a movie starring Peter Sellers in the three top roles) had the plot centering around the "Q-Bomb", a football-sized weapon capable of vaporizing an entire continent and finishing off the rest of the planet with its fallout. Only after the World's Smallest Nation has bullied the world into disarmament is it revealed (only to the readers) that the bomb was a dud.
- From the Star Wars Expanded Universe:
- The Sun Crusher
- The World Devastators
- Centerpoint Station
- The Galaxy Gun
- The Eye of Palpatine.
- The Nostril of Palpatine.
- Okay, we're joking about that last one. It was the name Han gave to a hypothetical superweapon, as part of a great speech lampshading the incredible number of useless superweapons the Empire tended to build. (And also a giant Take That to the Bantam novels, aka The Superweapon Of The Month Club, who brought you the majority of the above.)
- Darksaber deserves special mention; it was supposed to be just the "giant planet-destroying laser" part of the Death Star, but the builder cheated his contractors and it was shredded in an asteroid field without ever firing a shot.
- The Nova Bomb in Robert Heinlein's short story "Gulf".
- The title machines in Fred Saberhagen's Berserker stories.
- Hactar's Ultimate Weapon in Life The Universe And Everything used spacewarps to link the core of every sun in the universe to every other sun in the universe, and if triggered would cause every sun in the universe to explode. The species who ordered the creation of this piece of overkill tried to use it to blow up one of their enemies' munitions dumps. Luckily, the weapon didn't actually work.
- That's because Hactar, pondering the implications of such a weapon, designed it to be a dud. Later on he got qualms about that.
- In Gary Gygax's Gord the Rogue novels, the villains are on a quest to find three parts to a doomsday device that will free Tharizdun, a universe-destroying insane god who was imprisoned by the rest of the gods for eons. However, the villains do not want to USE the device -- instead they want to make sure the three parts are kept as far away from each other as possible. That doesn't work out too well...
- The antimatter canister in Angels & Demons.
- The Lexx.
- The title planet-eating device in the Star Trek: The Original Series episode "The Doomsday Machine".
- The Uthenium/cobalt bomb in The Bionic Woman (1970s) episode "Doomsday is Tomorrow".
- Doctor Who regularly encounters villains that revel in these.
- Sometimes even the good guys, as witnessed by UNIT's Earth-Destroying Osterhagen key in the series 4 finale.
- Which is small potatoes compared to the Multiverse-extinguishing Reality Bomb built by the Daleks, which required the Earth to function.
- Heck, the Daleks themselves are a sort of sentient Doomsday Device. The Doctor warned their creator exactly how dangerous they were when they were first being created. And he finished them anyway because he always kinda wanted to destroy everything.
- In "The Man Who Made Volcanoes" from Wonder Woman Season 2 (1977), the Amazon uses her whole body to block a ray from a massive volcano-inducing raygun, ending a threat to countries around the world. Another doomsday device from that series involved a character named Andros whose spaceship would destroy the world if he was not released from Nazi custody in time to defuse it ("Judgment from Outer Space," Season 1).
- The Strada Brac (note the actual spelling was never revealed) on Tracker. It could destroy an entire planet anyway, and it had the power to destroy the entire planet in a backwash of energy if taken through the wormhole as Zin wanted it to be. Hence hiding it at the Watchfire deep underground.
- Serpentera, first seen in Mighty Morphin Power Rangers. This was Lord Zedd's spaceship and the largest Zord ever built in the entire franchise, so huge that the original Megazord (which itself was the size of a skyscraper) could fit in its hand. It had weapons capable of obliterating entire planets. Unfortunately, it suffered a serious design flaw, being this Trope's equivalent of a gas-guzzler, burning through its fuel supply very quickly. Zedd eventually abandoned it, only for it (or more likely a prototype, seeing as it was smaller) to be discovered in Power Rangers Wild Force, by General Venjix. The villain was able to correct the flaw by giving it a "a neo-plutonium core", but it clearly had lost a lot of its former might, and was destroyed in a battle with one Ranger, taking Venjix down with it.
- Dilbert: Dogbert's built a few in his time.
- One mode of play from the Paranoia rulebook for High Programmers is Doomsday, where each player has a Doomsday weapon and the ability to use it. Paranoia indeed.
- The premise of the board game Mwahahaha is to collect the items needed to activate your Doomsday Device on a global scale and use it to take over the world.
- Warhammer 40,000 has these. Lots of them, actually. In every size, shape, and means of destruction imaginable.
- However, you have to consider, that most of them won't even scathe a tank of that universe.
- Chaos has an actual Doomsday Device strategic asset for Apocalypse. It tends to hurt a lot of people when activated.
- Tech Infantry has these, both by name in its backstory (The Three-D, or Dooms Day Device, is a device that can send a star into supernova, destroying an entire solar system, and is used to defeat a particularly nasty alien invasion), and by effect in the main story, what with huge starships several miles long capable of travel near the speed of light, and armed with weapons that fire miniature black holes. Several races can toss around asteroids big enough to wipe out the dinosaurs.
- Dungeons & Dragons
- Pandorym, one of the Eldritch Abominations outlined in the sourcebook Elder Evils was summoned to act as a living Doomsday Device, with the potential to slay gods.
- In Eberron filled quite nicely by Eldtrich Machines. What does an Eldtrich Machine do? Anything your plot demands it does, really.
- In Ravenloft, Azalin the lich-king constructed an arcane mechanism that's actually called a "Doomsday Device" (aka the "Infernal Machine")... only it's intended to let Azalin break out of the Land of Mists, not destroy it or hold it for ransom. (Its side effects did wipe out a major city, though.)
- In Traveller, the Sun Trigger of the Darrians, which can cause solar flares in a star and devastate its planets.
- Magic: The Gathering has several of these; one example would be the Plague Boiler. Three turns after it's played, everything in play that's not a land is destroyed.
- The Sons of the Patriots system in Metal Gear Solid 4. Every weapon, military vehicle, and even soldiers and mercenaries are integrated with a system that allows any piece of equipment to be used only by designated operators. Stolen equipment is completely useless and commanders can selectively revoke soldiers' permissions to equipment when they disobey orders. The system also includes a limited form of mind control that makes soldiers almost fearless and immune to pain. While its presented as an effective solution to put an end to the activities of warlords and rogue units, as well as making armies more efficient, things look completely different once the terrorists get the master password to the main server. With the press of a button, Ocelot shuts down every organized military force in the world with only his personal mercenary companies having a complete monopoly on military capability. The first three of five levels the heroes try to stop him, but ultimately fail as Ocelot takes control of SoP and effectively rules the entire world.
- Doctor Robotnik has fun with these. Bonus points for the Doomsday Project from the cartoon, which was central to the show's climactic story arc, but was presented for most of it as not much more than a big, enigmatic machine that he was really excited about.
- Singularity has the E99 Bomb, an explosive device the size of a football that represented Stalin's answer to America's military superiority. In an Alternate History, Nikita Khruschev deployed it against the US East Coast in a preemptive attack. There was no more East Coast after that.
- One of the songs in Mega Man ZX is even called Doomsday Device. It's a pretty awesome track. Have a listen.
- In Within a Deep Forest, your goal is to stop a bomb designed to freeze the entire world. There is a time machine in the game. Guess where it leads?
- Played for laughs in the web game Mastermind World Conquest. If you succeed in holding off the unending waves of enemies long enough for your Doomsday Device to succeed, you manage to destroy the world, narrowly getting away in your spacecraft... only to realize that you never thought about what to do next. You are then presented with options ranging from flipping off Earth's rubble to giving a Big No because you forgot to bring Cheesy Snacks.
- Similarly in the game Evil Genius, the player builds his secret HQ and accumulates resources to build any one of a number of Doomsday Devices. The game in won when the player has managed to avoid all the heroes and Secret Agents and actually conquer the world.
- In the Nasuverse, the alchemist of Atlas are said to possess a rather large stockpile of doomsday devices, built to fight back against whatever they predict will end the world. And, later, against their previous doomsday devices which are now part of how the world will end.
- EVE Online actually has a weapon called the Doomsday Device, used to wipe out fleets of ships.
- In Genius: The Transgression a high level Genius can build one of these, including players.
- Building a Doomsday Device is the final goal of Evil Genius for the PC. The player actually has a choice of three possible devices to build, including a Gravity Disruptor, an Earthquake Ray and an ID Eliminator (that basically turns everyone into your minion).
- In the Impossible Mission games, Mad Scientist Elvin Atombender's doomsday device attempts to crack the world's nuclear launch codes and cause an Earthshattering Kaboom.
- One of the premises of the Halo franchise is that all sentient life in the galaxy will end if the titular Halo rings are fired. As it turns out, there is a reason for this function; it is not a Pointless Doomsday Device, but a last-resort tool.
- Dwarf Fortress. Build your own doomsday machine. Envelop the world in fire and water and then mix them both and bury the world under a bed of obsidian. The type of doomsday device you make is limited only by your imagination and how many manic depressive alcoholics you kill trying to build it. The most infamous example would be Project "Fuck the World" of Boatmurdered.
- The Team Fortress 2 maps Gravelpit and Nucleus are fought over these. The former is a Ray Gun. The latter is...a gigantic spinning whirligig of light. Hanging over a radioactive pit. It's quite pretty.
- In X-COM Interceptor, you eventually discover that the aliens are building a giant, invincible Doomsday Machine, one shot from which will raze the Earth, killing everything and everyone there. Of course, it's invincible, so you can't directly harm it. The only solution X-Com scientists can come up with is the Nova Bomb, a human Doomsday Device that instantly causes a star to explode, wiping out everything in the solar system. Of course, there's nothing preventing you from using it on solar systems that aren't harboring the alien Doomsday Machine...
- In Half-Life 2, the Citadel becomes a bit of one, since it explodes - solely and completely because the energy from the explosion would help tear open a portal between Earth and the Combine home dimension. If that were to succeed, the human race would be utterly obliterated in minutes, once and for all, no rematches no second chances.
- Attack of the Mutant Penguins has the Doomscale, a giant scale for balancing penguins on. If too many alien penguins pile on and set it out of balance, it's Game Over.
- Parodied in The Demented Cartoon Movie: Evil Blah puts his "weird evil machine thing o' doom" into operation, even though nobody knows what it does.
- The Mercury Men try to pull the Moon down to crash into the Earth using a Gravity Engine.
- The SCP Foundation has contained quite a few of them, some scientific, some supernatural. The most extreme may be SCP-2399, which may have destroyed Earth had it not crashed into Jupiter. Even so, it caused the Great Red Spot when it did so.
- In Futurama, Professor Farnsworth's hobby is basically making spare doomsday devices in the same way old women knit sweaters.
- He even has a sentimental favorite. The Sphere-O-Boom.
- He now has a cabinet labeled Surplus Doomsday Devices which is full of more doomsday devices, including another Sphere-O-Boom.
Professor Farnsworth: I suppose I could part with one and still be feared...
- This is occasionally a problem on Jimmy Neutron; fortunately, Professor Calamitous is unable to finish anything he starts, leaving Jimmy a way to somehow save the day.
- Nimnul from Chip 'n Dale Rescue Rangers loved to make these, and every time they were powered by something more and more bizarre. His first one was powered by petting kittens.
- Busting Doomsday Devices is pretty much Kim Possible's hobby, with Dr. Drakken the major builder of them.
- The best is the machine that sucks the entire planet dry of breathable oxygen. It's activated once, it quickly destroyed, never referenced ever again and didn't make any sense in the original episode at all.
- In Exo Squad, the Big Bad Hitler-wannabe Phaeton constructs a Doomsday Device to blow up the Earth, should the Terrans come close to recapture it. Bat-shit insane as he may be, he actually has a good motivation for this, as destroying Earth is his way of retaliating for destruction of Mars, de facto Neosapien homeplanet.
- Something similar occurs in the 2009 Star Trek movie.
- In The Penguins of Madagascar special "Blowhole's Revenge", Dr. Blowhole creates a Doomsday machine that draws heat from the Earth's core to melt the polar ice-caps and therefore raise the sea-level and destroy all life on earth that cannot swim.
- The plot of most of the G.I. Joe mini-series involved Cobra attempting to make a doomsday device out of parts scattered all over the world. The Joe team then tries to keep Cobra from obtaining the parts. (Arise, Serpentor, Arise also followed this plot, however Cobra was genetically engineering a human being.)
- In She-Ra and the Princesses of Power, the Heart of Etheria is initially believed to be a superweapon created by the First Ones, able to channel the life energy of Etheria itself into a power capable of destroying whole planets. However, this is only partially true. The Heart is actually an energy source, which focuses its power through the Princesses, and then into the true Doomsday Device, She-Ra herself. Fortunately, She-Ra is determined to tell them that "I Am Not a Gun!".
- Truth in Television to an extent. Nobody has actually built one, but we have the capabilities to create a cobalt bomb that would kill every living organism on the planet Earth that was not sufficiently sheltered. It has been said that it would be impractical, but if you got the right combination of rich and crazy it could happen.
- Apparently, the Soviet Union had a semi-autonomous system set up during the Reagan years called Perimeter, or Dead Hand. The purpose of this system was so that, in the event of nuclear war, the country's nuclear arsenal could be deployed quasi-automatically in response to a nuclear attack on Soviet soil, regardless of whether or not the Soviet leadership was even still alive - thus allowing the Soviet nuclear arsenal to function as a doomsday device. Sound familiar?
- While it's sinister and Russian, the Perimeter system is not that different from the contingency plans of every Cold War era nuclear state - preserving a second strike capability was seen as essential to discourage opponents from making a surprise first strike. This is why ICBM-carrying submarines were developed and refined by all five major nuclear powers. The most charming contingency plan is certainly the UK's Letters of Last Resort.
- The automated systems used by the US and USSR gave false fire orders more than once, each time disaster was barely avoided by someone refusing standing orders because they didn't trust the system. Most were due to the systems misidentifying natural phenomena as incoming missiles.
- At one point, the scientists at Los Alamos entertained the possibility that a single atomic bomb could turn out to be one. Before the detonation of the first nuclear bomb, Trinity, bets were taken about the yield of the explosion. Predictions ranged from a dud to the ignition of the atmosphere itself and the total destruction of the planet. Although calculated to be almost impossible, the almost was enough to cause some anxiety among some of the physicists all the way up to the moment of the detonation. The moment of detonation is what is today called a "Fermi moment".
- There was also some concern that a thermonuclear device detonated in the ocean would cause chain reaction of nuclear fusion, which proved even less founded.
- Not entirely accurate. In a meeting during the design of the bomb at Los Alamos the idea was brought up and indeed caused quite a bit of alarm before some hasty calculations showed that it was impossible.
- Project Orion was meant to send a large spacecraft into space using a series of nuclear explosions, for peaceful exploration purposes. In order to help with military funding the scientists working on the project had to come up with military applications. One of the ideas was that since it could carry really heavy loads into orbit, they could give it a massive hydrogen bomb payload without the weight constraints of other delivery systems. It could then hover over the Soviet Union and be dropped if needed, wiping out the USSR and probably destroying the climate of the northern hemisphere in the process.