When Creator/OrsonWelles needed to come up with a HalloweenEpisode for the October 30, 1938 broadcast of his Creator/{{CBS}} radio program ''Radio/TheMercuryTheatreOnTheAir'', he decided to adapt Creator/HGWells' 1898 novel ''Literature/TheWarOfTheWorlds'' to a contemporary American setting. Rather than staging a regular radio play like all of the previous ''Mercury Theatre'' broadcasts, for this episode the program aired what seemed like a regular night of music, until reports came over the air of strange phenomena on the surface of Mars and what seem to be meteorites landing in locations across America...

By the time large alien tripods emerged from the cylindrical meteorite and began destroying the American countryside, many listeners believed that a bona fide AlienInvasion was taking place, and a nationwide panic ensued. Or so the UrbanLegends say, at least. If you believe the research done by Jeff Pooley and Mike Socolow, there was little to no actual panic and the [[http://mssv.net/realityart/wotwemails.html breathless reports that ran in the next day's newspapers]] were an attempt by said newspapers both to sell more papers and discredit radio--see NewMediaAreEvil below. However, the story's more complex than that. What people believed and continue to believe ''about'' the broadcast is as important as the fact that people believed the broadcast itself. The legend of this program has become part of American folklore.

Police and fire stations, newspaper offices and CBS affiliate stations nationwide, and the CBS New York studios, were swamped with thousands of telephone calls -- less a mass panic than a mass attempt to verify. People with loved ones in the area tried to call them (the jammed switchboards gave the impression that ''something'' was happening); some drove or flew there. Following the broadcast, CBS, the FCC and Orson Himself were flooded with mail.[[note]]Writing to a show or network back then was as common as comments sections and blog posts today.[[/note]] People of all ages and walks of life wrote that they'd believed the broadcast, although not all succumbed to panic, fled their homes or behaved irrationally.

Some thought the "invasion" was really Nazis; some faced "the end of the world" calmly;[[note]]Two sisters left their apartment to warn people, then decided to have cocktails before the Martians arrived. They later billed Welles for the cost of the drinks.[[/note]] others simply prepared as for a UsefulNotes/WorldWarI gas attack. College students fell for it by the dozen, much to the delight of those who knew it was a play and [[JumpScare set off firecrackers or shut off the lights]]. Many believed only until they heard something that told them it was a play. Some of the more extreme reactions may have been people who hadn't heard the show but heard ''about'' it from friends or neighbors who had. Many letter writers were thoughtful, wondering about radio's influence on behavior, on democracy.

The fact remains that CBS telephone switchboards across the country lit up like pinball machines, the calls not just from listeners but from reporters; the hallways outside the New York studio swarmed with reporters and cops who besieged the cast and crew after the show until they had to leave via a rear exit; Welles himself ended the program by saying that the program was little more than "dressing up in a sheet, jumping out of a bush, and saying 'Boo!'" and suggesting that the audience shouldn't be taken in by make-believe stories on the radio. Later that night, the ''New York Times'' building's famous neon headline crawler in Times Square was announcing "ORSON WELLES CAUSES PANIC."

Welles thought it was the end of his career. But the one-hour program became a media sensation. Welles and his show were instantly internationally famous. The Campbell Soup Company jumped at the chance of becoming the sponsorless show's underwriter, and ''The Mercury Theatre on the Air'' was renamed ''The Campbell Playhouse''. Whether or not Welles used the format to [[ForTheEvulz intentionally troll radio listeners]] is still up for debate [[note]]massive evidence has been found that he did not, and was horrified at what had happened[[/note]], but the show made him a star, and led before too long to a movie contract, and ''Film/CitizenKane''.

The broadcast was actually [[http://www.war-ofthe-worlds.co.uk/war_worlds_quito.htm recreated in 1949 in Quito, Ecuador]] by director Leonardo Páez, ''definitely'' as an intentional prank, although not on the diabolical level that's been attributed to him. A huge riot erupted when listeners were finally told it was a gag. An angry mob with TorchesAndPitchforks set fire to the station, with 100 workers trapped inside. Seven people died. It was tried again in [[http://www.youtube.com/watch?v=g-oTTyGOkIg an updated version by WKBW]] in Buffalo, New York in 1968. [[http://www.youtube.com/watch?v=H1A0R1vldv4 Conceived]] by engineer-director Dan Kriegler and program director Jeff Kaye, it used the station's news staff and contemporary music and commercials and put the action in nearby Grand Island. Instead of a script, Kaye wrote out a series of events and had the news people read them as they would normally. In spite of fairly frequent "this is a dramatization" announcements, the show's format meant that people who tuned in late were going to think, at least for a few minutes, that it was real. A local newspaper, several police officers and the Canadian National Guard (which sent troops to the border) were among those deceived. [[http://www.youtube.com/watch?v=eXTEUM4OF7Q WKBW updated the format again and rebroadcast the show in 1971]]. For the 50th anniversary of the broadcast in 1988, Creator/{{NPR}} aired [[https://www.youtube.com/watch?v=wIeYnoutthU yet another remake]] directed by Creator/TheFiresignTheater's David Ossman and featuring several of the network's on-air personalities. And in 2008, [[https://www.youtube.com/watch?v=xjF0KVDdMuo another revival]] was presented on NPR by the LA Theatre Works with a nearly all-''Franchise/StarTrek'' cast including Creator/LeonardNimoy as Prof. Pierson and Gates [=McFadden=] as [[GenderFlip reporter Carla Phillips]].

The incident was dramatized in "The Night America Trembled", a 1957 episode of ''Westinghouse Studio One'', and ''The Night That Panicked America'', a 1975 MadeForTVMovie co-starring Creator/JohnRitter; and touched upon in feature films like ''Film/RadioDays'' (1987) by Creator/WoodyAllen. Two episodes of Music/{{Negativland}}'s weekly KPFA radio happening ''Over the Edge'', helmed by master culture jammer Don Joyce, focused on the program as an example of "[[https://archive.org/details/OTE_20060518_How_Radio_Was_Done_3_-_WOTWW How Radio Was Done]]" (2006) and a 1999 examination of how we discern [[https://archive.org/details/OTE_19990200_True_and_False true from false]] information in modern life. It was analyzed in a [[http://www.radiolab.org/story/91622-war-of-the-worlds/ hysterically funny episode]] of NPR's ''Radiolab'' in 2008, talking about the power of mass media and humanity's need for storytelling. The historical events and situations that set up this incident are described in PBS' 2013 ''American Experience'' episode "[[https://www.youtube.com/watch?v=M1iLFp6XyPY The War of the Worlds]]". There's more in A. Brad Schwartz's 2015 book ''Broadcast Hysteria: Orson Welles' War of the Worlds & the Art of Fake News''.

This incredibly innovative broadcast is the TropeMaker for DeadlineNews, PhonyNewscast, ThisJustIn, WeAreExperiencingTechnicalDifficulties, and WeInterruptThisProgram.

!!The radio version contains examples of:

* AdaptationalBadass: The Martians, despite going up against more contemporary military technology (United States National Guardsmen equipped with [[GasMaskMooks gas masks]] and [[GatlingGood machine-guns]], military airplanes, etc.), manage to prove much more durable and threatening than in the original novel, and ''without'' having the force-fields they are depicted with in later film adaptations.
** For example, only ''one'' fighting-machine is brought down in combat [[hottip:*:In the book, one is gunned down by artillery fire, and two or three others are destroyed by a warship]], and it took an artillery barrage ''and'' a bomber plane [[HeroicSacrifice crashing into it]] to eliminate it. Also, the Black Smoke is deployed ''before'' said machine is destroyed, and it's shown to render gas masks ''useless''. And the real kicker is that the very first fighting-machine deployed by the Martians was pitted ''alone'' against an army of 7,000 National Guardsmen that were all using rifles and machine-guns, and left only ''120'' known survivors.
* AfterTheEnd: The last third of the one-hour show quits the PhonyNewscast format, and follows Pierson as he writes in his journal about his harrowing trip from Grover's Mill to New York City. He sees one living person the whole way.
* AndNowForSomethingCompletelyDifferent: About forty minutes in, the narrative changes completely to the aforementioned professor writing in his journal, and then briefly follows the professor and a stranger discussing Martian theories before returning to the journal again.
* AudioAdaptation: Of the famous novel.
* BattleDiscretionShot: When the first of the Martian fighting-machines rises from the cylinder, the radio feed from the National Guard stationed at Grover's Mill is conveniently cut short ''right before'' the soldiers open fire on the machine, and we are instead treated with a report on the aftermath of what turned out to be a CurbStompBattle (that the ''Martian'' won) from the CBS studio.
* CirclingVultures: They draw Pierson's attention to the corpses of the Martian invaders, lying around an abandoned New York after the Martians died from Earth-bound microbes.
* CommercialBreakCliffhanger: Averted. As ''The Mercury Theatre of the Air'' didn't have a sponsor, there didn't need to be a break in the program for advertisements; this helped keep up the {{Kayfabe}} of the broadcast. The only break acts as a transition between the faux-radio program and Pierson's AfterTheEnd narration.
* ContrivedCoincidence: Phillips the news correspondent conducts an interview with Professor Pierson live on the air, discussing the mysterious gas explosions on Mars. Then objects are observed to be falling from the sky and landing in rural New Jersey--just a few miles from the observatory, conveniently allowing Pierson and Phillips to go there and report.
* DeadlineNews:
** Carl Phillips, reporting live from Grover's Mill, is burned to death mid-sentence by a Martian heat ray.
** The reporter in New York narrates the advance of the Martian tripods until he is killed by their poison gas. The broadcast goes to dead air, then one voice comes on, repeatedly asking if anyone is out there.
* DecoyProtagonist: At first, Carl Phillips the news reporter appears to be this story's counterpart to the unnamed protagonist of the novel, with Professor Pierson the astronomer being the [[SacrificialLamb Ogilvy]] stand-in. Then it gets subverted, when Carl Phillips is found incinerated by the Martians' Heat-Ray, and Pierson fills the role of protagonist after being shown to survive the attack.
* EmergencyPresidentialAddress: Averted by ExecutiveMeddling. It was originally intended for the unnamed Secretary of the Interior[[note]](It would have been Harold Ickes, who really [[https://youtu.be/G2Tk87amlxQ?t=1m29s didn't sound much like Roosevelt]].[[/note]] to be President UsefulNotes/FranklinDRoosevelt, but CBS objected to this detail. That didn't stop Welles from having the actor imitate Roosevelt's voice.
* EverybodysDeadDave: In the radio drama, large numbers of people are killed, either by heat rays or poison gas spewed from the alien spaceships. Several "field reporters" make note of this fact before they, too, succumb to the imminent danger. After a cutaway where a reporter describes millions of fleeing New Yorkers dying en masse falling victim to gas clouds or falling into the Hudson River to commit suicide a ham radio operator desperately calls out, "2X2L calling CQ. Isn't there anyone on the air? Isn't there anyone on the air?! Isn't there ... anyone???!!!"
* FaceDeathWithDignity: The radio reporter in New York[[note]]played by ''PerryMason'''s Ray Collins[[/note]], who narrates the advance of the Martian tripods into the city, knowing perfectly well he's going to die. ("This is the end, now.")
* {{Foreshadowing}}: The opening narration, adapted from the beginning of the novel, muses on how we were watched by the Martians as we might watch "the transient creatures that swarm and multiply in a drop of water". In the end it is those creatures that destroy the Martians.
* FoundFootage: A UrExample and perhaps the only radio version of this trope.
* HorrorDoesntSettleForSimpleTuesday: The supposed Martian invasion begins on the night before Halloween.
* {{Kayfabe}}: Welles was concerned that ''War of the Worlds'' was such a well-known antique that bored audiences would tune out, so he repeatedly emphasized realistic portrayals and the "radio news" format. He was mostly occupied with the theatrical play he was putting on at the same time, so left it to the cast and crew to do the WorldBuilding necessary to make it fully believable.
* KilledMidSentence: The at-the-scene radio reporter, Carl Phillips. Or, at least, the on-site radio equipment is destroyed while he's in mid sentence. (His charred remains are later identified.)
--> [describing the Martian death ray] "...coming this way, about twenty yards from my ri--"
** The pilot who crashes his plane into a Martian tripod has his transmission cut off mid-sentence as well.
* LargeHam: Welles' opening narration is ''very'' hammy. He is more restrained when performing as Professor Pierson within the program.
* MoodWhiplash: Terrifying reports of Martian spaceships landing on Earth? We'll get back to that in a second, but first, here's Ramon Raquello and his orchestra!
* MoralGuardians: Lots of them in the wake of the sensationalized post-broadcast reports, calling for censorship, speaking up against "terrorizing" broadcasts, the fake-news format (which wasn't new, as any listener to ''March of Time'''s news re-enactments could have told you), radio as a corrupter of children, &c., &c. The kids, of course, knew the story or caught on quickly; thousands wrote fan letters to Welles.
* NarratingTheObvious: This trope, usually nigh-unavoidable in radio drama, is here justified InUniverse. Usually in an audio play characters have to explicate things that they are seeing for the benefit of the audience. Thanks to the decision to stage this show as a PhonyNewscast, and a reading from Pierson's journal in Act Three, the characters are already narrating the action, which makes the whole broadcast sound more natural.
* NewMediaAreEvil: It seems that newspapers ([[http://books.google.ca/books?id=GeWm-zM3NEoC&lpg=PP1&dq=Little+Green+Men,+Meowing+Nuns+and+Head-Hunting+Panics:&pg=PA219&redir_esc=y#v=onepage&q&f=false embellished the facts to make radio look bad]]).[[note]]Embellishing the facts just to sell papers was typical, especially for Hearst papers. They used huge scare headlines and lurid, often grossly exaggerated, tabloid-like narratives. This caused rumors which then spread to other papers and radio news.[[/note]] Latter-day research has found that the number of people who were taken in by the faux-news format [[http://www.csicop.org/sb/show/shootout_with_martians_in_the_wake_of_the_1938_broadcast_panic wasn't as high as previously thought]]. And [[https://www.amazon.com/Broadcast-Hysteria-Orson-Welless-Worlds-ebook/dp/B00OFID7TE/ref=tmm_kin_swatch_0?_encoding=UTF8&qid=&sr= those who did believe it mostly reacted rationally]]. The "mass panic" reported in the press, with thousands fleeing the city, simply didn't occur, although some individual incidents -- like the woman who ran into the Indianapolis church to announce the "end of the world"[[note]]This happened in several other cities as well.[[/note]] -- were verified. Letters and telegrams have been found from people who had indeed believed it, many ''congratulating'' Welles on his ingenuity. To sum up, about six million people listened, and about a million of them, however briefly, believed it was real.
* PeopleFarms: The rather unhinged militia veteran that Pierson meets in Newark--the only living person he finds between Grover's Mill and New York City--anticipates that the good folks of soft middle-class America will submit themselves to the Martians and live on people farms.
* PhonyNewscast: UrExample, TropeMaker. This is the format for the first two-thirds of the show, as a program of dance music is interrupted by increasingly urgent news reports about gas explosions on Mars and mysterious objects plummeting to Earth in New Jersey. See WeInterruptThisProgram below.
* RealTime: For roughly the first third of the program, up to the death of reporter Phillips, as radio bulletins break the news of the Martian invasion. Even before the PhonyNewscast portion of the show ends, the RealTime part is basically abandoned, as the show skips ahead to military confrontations with the Martians and the Martian advance on New York.
* SettingUpdate: Welles moved the setting of the story from H.G. Wells's Victorian England to the United States of TheThirties.
* SparedByTheAdaptation: Pierson, the Ogilvy {{Expy}}, survives the invasion, unlike his novel counterpart.
* SwitchingPOV: The first part is comprised of various reports and interviews from different people. The last part follows a lone professor.
* ThisJustIn: The studio begins to overflow with reports of the Martian walkers arriving and destroying power lines and transport routes.
* ToServeMan: At least part of the reason the Martians invaded is, apparently, to eat people.
--> '''Pierson''': I've seen the Martians...feed.
* WeAreExperiencingTechnicalDifficulties: After Phillips's broadcast is cut off by him being burned up by the heat ray.
* WeInterruptThisProgram: The first ten minutes of the show involves "Ramon Raquello and His Orchestra" playing Thirties dance music, with the plot occasionally interrupting to provide breaking news. Later on it changes to piano music by Debussy, in a textbook example of classical music on radio being shorthand for world-threatening disaster.
** This is one reason so many people ''did'' believe it. UsefulNotes/WorldWarI and its gas warfare was fresh in their memories, UsefulNotes/WorldWarII was brewing in Europe; America was primed for possible attacks or invasion. Regular programming experienced constant interruptions by news bulletins about Hitler's conquests. Sometimes one bulletin would be interrupted by another! So they heard "Martians", but thought it was really Nazis making it ''look'' like a Martian attack.