-->See androids fighting
-->Brad and Janet!
-->Anne Francis stars in
-->''Forbidden Planet!''
-->-- "Science Fiction, Double Feature", ''Film/TheRockyHorrorPictureShow''

[[Creator/WilliamShakespeare Shakespeare]]...'''[[AC:[[RecycledInSpace IN SPACE!]]]]'''

Loosely adapted from Shakespeare's ''Theatre/TheTempest'' with a few nods to Creator/HPLovecraft's ''Literature/AtTheMountainsOfMadness'', ''Forbidden Planet'' tells the tale of an Earth rescue mission to the planet Altair IV in order to determine the fate of the starship ''Bellerophon'' that landed an earlier expedition. United Planets Cruiser ''[=C57D=]'' arrives to find the sole survivors are Dr. Edward Morbius, his daughter, Altaira, and their robot house servant, Robby. Their investigation into the mystery reveals secrets that can change the course of human civilization but unleashes a hideous monster in the process.

A classic of '50s science fiction films whose story, production values, and special effects hold up well even by today's standards. It is the first film whose soundtrack consists entirely of electronic music and which was written for magnetic tape (and it was made by a couple, Louis and Bebe Barron).

By the way, if you watch it and can't help but think it feels completely like a ''Series/{{Star Trek|The Original Series}}'' episode without Mr. Spock, it's no accident - Gene Roddenberry fully admitted that it was his inspiration for his series. It also gave some Japanese creators their momentum, and its elements can be found again in Anime/SpaceBattleshipYamato and Anime/SpaceRunawayIdeon.

It spawned a JukeboxMusical version called ''Theatre/ReturnToTheForbiddenPlanet'' which hit its popularity in the 90s, winning an award and gained a slight cult following.

!!This film provides examples of:

* AllGirlsWantBadBoys: Altaira is warned that the captain can't be trusted with women, and she promptly zeroes in on him.
* AllMenArePerverts: Invoked on two occasions.
** The XO, in an attempt to get Altaira for himself, implies that his captain and the ship's doctor can't be trusted alone with women. He then proceeds to prey on her innocence to seduce her.
** The Captain attempts to justify his crew's behavior by noting they are all in superb physical condition, average 24 years old, and have been cooped up on the ''[=C57D=]'' for 13 months. Mind you he need not apologize. Altaira is thoroughly enjoying herself.
* ArtisticLicensePhysics: Nothing could survive three billion electron volts? Really? ''Tissue paper'' could withstand far more than that! The thermal energy sucked out of your skin when a snowflake melts on it is about a billion times higher. A common misconception is that "electron volt" is the same as a regular volt. Actually, it's the energy gained by a single electron accelerated through an electric potential difference of one volt. This is an incredibly tiny amount of energy.
* BelligerentSexualTension: The captain and Altaira.
* BigRedButton: Actually a switch, that activates the countdown on the Krell planetary SelfDestructMechanism.
* BittersweetEnding: True they manage to keep Robby who is stated to be beyond state of the art, but Krell technology is thousands of years ahead of anything we have, and just from what we see they could have revolutionized agriculture, power generation and metallurgy to such a degree that it would have been one of the most important discoveries in human history.
* BreakoutCharacter: JustForFun/RobbyTheRobot. Robby was re-used in many subsequent sci-fi movies not only due to his popularity but also to recoup the tremendous cost of constructing him.
* CoversAlwaysLie: See that poster up there? The robot's not the bad guy. And he never carries the woman [[PietaPlagiarism like that]]. On a smaller note, she and Robby look nothing like that. The poster was most likely a Shout-Out to Pulp Fiction magazines, like Amazing Stories.
* CrystalSpiresAndTogas: The Krell, before the destruction of their civilization, lived in "cloud-piercing towers of glass and porcelain and adamantine steel".
* DeadlyUpgrade: The doctor uses an UpgradeArtifact to become smart enough to learn the planet's secrets, but [[FinalSpeech dies in the process]]. Earlier, Morbius did the same thing and survived, but...well, [[EnemyWithout see below]].
* DeadpanSnarker: Robby to a certain extent.
--> '''Commander Adams:''' Nice climate you have here. High oxygen content.\\
'''Robby:''' I rarely use it myself, sir. It promotes rust.\\
'''Altaira:''' Robby, I want you to run up a new dress for me.\\
'''Robby:''' Again?
* DeathOfTheHypotenuse: Lieutenant Jerry Farman, which eliminated any possibility that he could interfere with Adams and Altaira getting together.
* DoAnythingRobot: Robby, an early example. He is incredibly strong, has a vast database, is a MatterReplicator, and although he can't hurt humans, he can disarm them, and has some kind of stinger ray for shooing away animals.
* DoesNotLikeShoes: Altaira is barefoot for most of the movie.
* EatingTheEyeCandy: Altaira is clearly thrilled at having a whole shipload of hunky spacemen to choose from and eager to gain experience.
---> "You're lovely, Doctor, but the two on the end are ''unbelievable''!"
* EldritchAbomination: The Id Monster, to a certain extent. It doesn't drive people insane, but it's quite capable of shredding anything that gets in its way, and the Krell machinery feeding it gives it effectively ''infinite'' strength.
* EnemyWithout: Coupled with UnstoppableRage, Morbius' id can use the ForgottenPhlebotinum that runs the planet's machines to create a monster literally born of jealousy and possessiveness to deal with intruders, which his conscious self is powerless to stop.
* EternalEngine: The Krell machinery, which was underground, 40 miles long ''per side'', in the shape of a cube, and full of fusion reactors.
* EurekaMoment: After the id monster's attack on the ship, Adams and Doc Osgrow discuss how it could withstand their weapons, and the Doc reasons that it was [[HealingFactor regenerating itself]] "from one microsecond to the next!" The phrasing gives Adams the key clue to the monster's source (Morbius said the same thing about a mental projection he'd showed them, made with the Krell machinery).
* ExactWords: In a secondary example, Cook "sneaks out" of the ship to obtain 60 gallons of liquor from Robby the Robot at their meeting place amidst the rocks. While engaged in conversation with Cook, Robby pauses and scans the area, causing the human to ask if someone's "coming this way", which Robby reassures him is not the case. [[spoiler:An invisible monster proceeds to sneak aboard the ship and kill a crew member]]
* {{Expy}} The main characters mirror the main characters of ''Theater/TheTempest'': Morbius is Prospero, Alaira is Miranda, Robby is Ariel, the Id Monster is Caliban, the Captain is Ferdinand, and the Krell serve the position of Sycorax.
* FlyingSaucer: This time the humans have one (the United Planets Cruiser ''[=C57D=]'', said to be the inspiration for the saucer section of the ''[[Series/StarTrekTheOriginalSeries U.S.S. Enterprise]]'').
* FourthDateMarriage: Late in the movie Altaira absolutely refuses to deny her love for the Captain, even though they've known each other for like three days by that point.
* FriendToAllLivingThings: Altaira, until she first feels sexual desire, at which point it shuts off like a light switch. The captain is weirdly GenreSavvy about this.
* FutureMusic: Alleged to be the first film with an all-electronic score.
* GetTheeToANunnery[=/=]IncrediblyLamePun: [[http://www.worthpoint.com/worthopedia/original-porcelain-enamel-1d-monsters-247625879 Id Monsters]], for that fizzy sweet apocalyptizing goodness.
* GhostPlanet: The planet Altair IV is essentially this, with just Dr. Edward Morbius and his daughter living there.
* GoodHairEvilHair: Dr. Morbius' goatee pegs him as close to evil, while Adams and co. are clean shaven to the point of being shiny.
* HaveAGayOldTime: Dr. Morbius says that, compared to the Krell, he would be a "moron," which at the time was a technical term for someone with an I.Q. in the 51-70 range.
* TheHeartless: The id.
* HeroicSacrifice:
** Knowing that the Krell machine could kill a human using it, The Doctor runs off when Commander Adams is distracted to use it. This could be hubris and him wanting to use it first (The Commander had insisted he go first), or taking the risk on himself to spare The Commander. Either way, he lives just long enough to reveal the nature of the id monster and provide the means of saving everyone.
** Once he realizes that the id monster is ''him'', Dr. Morbius begs Commander Adams to kill him to save his daughter. He then overloads the machine, resulting in his death.
* InnocentFanserviceGirl: Altaira, being completely unaccustomed to normal social mores. (Though if you look when she gets out of the water you can see she's wearing a flesh colored suit)
-->'''Altaira''': "What's a bathing suit?"
* JustifiedTrope: Why is the self-destruct device so easy to access? Because everyone on the planet was (externally) morally perfect.
* LogicBomb: Robby's "built-in safety factor": he is compelled to obey Morbius, but is also compelled not to harm a rational being, and he shorts out if those two mandates come into conflict. Backfires when Morbius, in a panic, orders Robby to kill the Monster, and trips the failsafe instead, because Robby realizes that the Monster is being generated by the Krell machine from Morbius' own subconscious. The only way for Robby to kill the monster is to kill Morbius, which the failsafe will not allow, causing Robby to freeze up and be unable to take any action.
* LostTechnology: The Krell, an alien race who lived on the titular Planet but died out hundreds of thousands of years ago, left behind an artifact that could dramatically boost the intellect of those few primitive, backward humans who survived the process. Their machines could also read the thoughts of those who used the artifact, and even cause some of those thoughts to become reality.
* MadScientistsBeautifulDaughter: Altaira's father, Dr. Morbius, keeps her completely isolated from the social world outside Altair IV.
* MarsNeedsWomen: The poster of Robby carrying Altaira. Once you know he's harmless, it tends to lose its impact.
* MeaningfulBackgroundEvent: Coupled with {{Foreshadowing}}: During the id monster's big attack on the ''[=C57D=]'', the film inserts a shot of Morbius sleeping (and having a nightmare) in the Krell lab; behind him, the energy gauges of the Krell machinery are lighting up one after the other, and darken once he awakens. The same thing happens later during the climax in that same lab, when Adams is trying to convince Morbius of the monster's true source.
* NeverTrustATrailer: See the poster up at the top? Not does the depicted event never happen, it's intentionally misleading. (There is a notable Robby fake-out in the movie that works better if you've seen the poster).
* NoManShouldHaveThisPower: Dr. Morbius insists that humanity won't be able to handle the power granted by the Krell artifacts. Captain Adams resents Morbius setting himself up as the arbiter of this technology; when Morbius himself can't handle the power, Adams realizes this really is too much power for humanity, so he doesn't object to destroying the entire Krell laboratory.
* NothingIsScarier: Most of the appearances by the id monster feature...well, nothing. The creature is invisible unless 'colored' by some sort of energy (ie, the perimeter fence, blasters, etc). In fact, the only thing seen during its entire first 'appearance' is footprints in the dust and dented stairs when it enters the ship, although one crewman can hear its breathing.
* OfficerAndAGentleman: TheCaptain is one, and protects naive Altaira from his lewd crew.
* OverprotectiveDad: Morbius, subconsciously. Morbius said Altaira could leave for Earth whenever she wished, and might have even believed it at the time. The unconscious desires of his id have a different opinion, to the point that they manifest as a monster to destroy others in order to protect her.
* OnlySixFaces: The space crew can seem this way, since they're all clean shaven, brown-haired men with similar haircuts and identical uniforms (with the exception of the cook). A slightly darker shade of grey on the Captain's outfit to make him stand out or a patch with medical insignia on the ship's doctor might have helped a bit.
* OverrideCommand: Altaira uses "Command Override Archimedes" to get Robby to leave against her father's orders.
* PapaWolf: A shipload of sex starved spacemen sniffing around his daughter brings out Morbius' 'creature from the id' eventually endangering even her with its unreasoning possessive rage.
* PerilousPowerSource: The Krell cube's core, filled with nuclear reactors. Morbius even refrains from showing as "One cannot behold the face of [[{{Medusa}} the gorgon]] and live!" ("Gorgon Gazing" was even [[Administrivia/EverythingYouWantedToKnowAboutChangingNames the former]] [[TropeNamer trope name]]).
* PietaPlagiarism: Robby carrying Altaira in the poster.
* PleasePutSomeClothesOn: Captain Adam's reaction to Altaira's [[InnocentFanserviceGirl being exposed while swimming.]]
* {{Precursors}}: The Krell. The movie only gives vague hints on what they might have looked like.
* RagnarokProofing: Averted, and not. In the words of Doctor Morbius, ''"...seemingly on the threshold of some supreme accomplishment which was to have crowned their entire history, this all-but-Divine race [the Krell] perished in a single night. In the two thousand centuries since that unexplained catastrophe, even their cloud-piercing towers of glass, and porcelain, and adamantine steel have crumbled back into the soil of Altair IV, and nothing, absolutely nothing remains above ground"''. He said, '''''above''''' ground...
* RaygunGothic: One of the definitive examples; Robby the Robot in particular came to be iconic of the style.
* RealityHasNoSoundtrack: Instead of a conventional score, the film uses electronic sounds to suggest an otherworldly atmosphere.
* ReversePolarity: Used by the ship's crew during the landing process on Altair 4.
* RobotAntennae: Robby the Robot has two asymmetrical circular antennae as "ears."
* RobotBuddy: Robby is perhaps the UrExample of this trope. Polite, friendly and helpful, though occasionally droll and sarcastic (but never malicious), it's little wonder why he was the breakout star of the film, especially when you see him just [[SugarWiki/FunnyMoments standing around getting drunk]] with the ''[=C57D=]'''s cook.
* RobotNames: The classic "Robby the Robot" even [[AddedAlliterativeAppeal alliterates]]!
* RogerRabbitEffect: The id monster, during his on-screen appearance, which was animation done for the film by Disney animator Joshua Meador.
* SeeTheInvisible: The monster's tracks can be seen, and its outline becomes visible when it moves between the energy-fence's pylons.
* SelfDestructMechanism: At the end, destroys the planet and all the knowledge of the Krell.
* SelfHealingPhlebotinum: Said of the Krell machines.
* SocietyMarchesOn: The opening narration seems to imply a certain amount of equality in the future... and then immediately shows us a massive space exploration crew made up entirely of white men. The attitudes of said white men towards Altaira are also noticeably very 1950's, particularly the attitude towards her skimpy outfits. There's even one point where Commander Adams tells Altaira to start covering herself (because it's her responsibility to keep the men from [[MaleGaze ogling her]]), and she has Robby make her a new dress because just putting on a pair of pants would be unthinkable.
** Those attitudes were somewhat justified because, when the film was made, Sputnik I hadn't been launched into orbit yet and no one knew ''if'' someone could survive both the Zero-G of outer space and the G-forces of an orbital rocket launch or atmospheric re-entry. The requirements for the first group of American Astronauts was for military test pilots with large amounts of jet experience ... which excluded most male American pilots and all female American pilots.
* SpockSpeak: The robot.
* StarfishAlien: The Krell are never shown, but they are clearly not humanoid, based on the tools and furnishings they leave behind.
* StealthSequel: Robby the Robot was so popular he appeared as the co-star in a B&W children's movie called TheInvisibleBoy. In an application of this trope, the movie was implied to be in the same universe as Forbidden Planet, with Robby being pulled back in time to the [[TheFifties present day]] by a scientist's experiment. Some releases of ''Forbidden Planet'' include ''The Invisible Boy'' as DVDBonusContent.
* ThouShaltNotKill: The robot is programmed to shut down should he be ordered to harm any "rational being". This feeds directly into a LogicBomb, when the robot is ordered to do exactly that.
* TouchOfTheMonster: The above poster -- though subverted as Robby is the resident RobotBuddy.
* VirginPower: Altaira's communion with the animals. She loses the ability as soon as she starts to enjoy kissing Commander Adams.
* WhatDidYouExpectWhenYouNamedIt: The original colonists' ship is called the Bellerophon. In Myth/ClassicalMythology, Bellerophon was a great hero who tamed the Pegasus. However, he also fell victim to [[{{Pride}} hubris]], and was punished by being sent crashing down to Earth from his mount, where he died a blinded cripple.
* WhatIsThisThingYouCallLove: The crew is eager to demonstrate the human custom of "kissing" to Altaira. She is initially unimpressed.
* YouAreNotReady: Morbius' dictum that he would parcel out the dead planet's {{Phlebotinum}} as he saw fit so as not to corrupt humanity. Eventually, TheCaptain agrees with him that ''none'' of it should be used by anyone else, and the planet is made to self destruct.