See androids fighting Brad and Janet!
—"Science Fiction, Double Feature", The Rocky Horror Picture Show
Loosely adapted from Shakespeare's The Tempest with a few nods to H.P. Lovecraft's At the Mountains of Madness, Forbidden Planet tells the tale of an Earth rescue mission to the planet Altair IV in order to determine the fate of an earlier expedition. United Planets Cruiser C57D arrives to find Dr. Edward Morbius, the sole survivor of the starship Bellerophon, and his daughter, Altaira. 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. (The sexual politics, by contrast...) It is the first film whose soundtrack consists entirely of electronic music.
By the way, if you watch it and can't help but think it feels completely like a 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.
The movie was named to the National Film Registry in 2013.
- All Men Are Perverts: 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.
- Big Red Button: Actually a switch, that activates the countdown on the Krell planetary Self-Destruct Mechanism.
- Breakout Character: Robby.
- 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.
- Covers Always Lie: See that poster up there? The robot's not the bad guy. And he never carries the woman like that. On a smaller note, she and Robby look nothing like that. Did the poster designers even watch the movie?
- The poster was most likely a Shout-Out to Pulp Fiction magazines, like Amazing Stories.
- Crystal Spires and Togas: The Krell, before the destruction of their civilization, lived in "cloud-piercing towers of glass and porcelain and adamantine steel".
- Deadpan Snarker: Robby to a certain extent.
Commander Adams: Nice climate you have here. High oxygen content.
- Deadly Upgrade: The doctor uses an Upgrade Artifact to become smart enough to learn the planet's secrets, but dies in the process. Earlier, Morbius did the same thing and survived, but...well, see below.
- Did Not Do the Research/Science Marches On: Altair appears as a spherical, reddish star in the film when it was well known to be a whitish A7 subgiant. In the 1960s, astronomers found it to be egg-shaped due to its rapid rotation.
- Does Not Like Shoes: Altaira is barefoot for most of the movie.
- Eldritch Abomination: The id monster.
- Enemy Without: Coupled with Unstoppable Rage, Morbius' id can use the Forgotten Phlebotinum 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.
- Eternal Engine: The Krell machinery, which was underground, 40 miles long per side, in the shape of a cube, and full of fusion reactors.
- Flying Saucer: This time the humans have one (United Planets Cruiser C57D)
- Friend to All Living Things: Altaira, until she first feels sexual desire, at which point it shuts off like a light switch. The captain is weirdly Genre Savvy about this.
- Future Music: Alleged to be the first film with an all-electronic score.
- Ghost Planet: the planet Altair IV is essentially this, with just Dr. Edward Morbius and his daughter living there.
- Good Hair, Evil Hair: Dr. Morbius' goatee pegs him as close to evil, while Adam's and co. are clean shaven to the point of being shiny.
- Have a Gay Old Time: 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.
- The Heartless: The id.
- Innocent Fanservice Girl: 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?"
- Justified Trope: Why is the self-destruct device so easy to access? Because everyone on the planet was (externally) morally perfect.
- Logic Bomb: 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.
- Mad Scientist's Beautiful Daughter: Altaira's father, Dr. Morbius, keeps her completely isolated from the social world outside Altair IV.
- Mars Needs Women: The poster of Robby carrying Altaira. Once you know he's harmless, it tends to lose its impact.
- No Man Should Have This Power: 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.
- Officer and a Gentleman: The Captain is one, and protects naive Altaira from his lewd crew.
- She's not all that naive. She 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!"
- Overprotective Dad: Morbius, to the point he unleashes his id as a monster to destroy others in order to protect her.
- 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 had a different opinion.
- Override Command: Altaira uses "Command Override Archimedes" to get Robby to leave against her father's orders.
- Pietà Plagiarism: Robby carrying Altaira in the poster.
- Please Put Some Clothes On: Captain Adam's reaction to Altaira's being exposed while swimming.
- Precursors: The Krell. The movie only gives vague hints on what they might have looked like.
- Ragnarok Proofing: 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...
- Raygun Gothic
- Reverse Polarity: Used by the ship's crew during the landing process on Altair 4.
- Robot Names: The classic "Robby the Robot" even alliterates!
- Roger Rabbit Effect: The id monster, during his on-screen appearance, which was animation done for the film by Disney animator Joshua Meador.
- Sci-Fi Writers Have No Sense of Scale: 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.
- Self-Destruct Mechanism: At the end, destroys the planet and all the knowledge of the Krell.
- Showing Off the Perilous Power Source: The former Trope Namer.
- Spock Speak: The robot.
- Stealth Sequel: Robby the Robot was so popular he appeared as the co-star in a B&W children's movie called The Invisible Boy. 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 present day by a scientist's experiment.
- Thou Shalt Not Kill: The robot is programmed to shut down should he be ordered to harm any "rational being."
- Which feeds directly into a Logic Bomb, when the robot is ordered to do exactly that.
- Touch of the Monster: The above poster, which happens in the film but is horribly misleading.
- What Is This Thing You Call Love?: The crew is eager to demonstrate the human custom of "kissing" to Altaira.
- You Are Not Ready: Morbius' dictum that he would parcel out the dead planet's Phlebotinum as he saw fit so as not to corrupt humanity. Eventually, The Captain agrees with him that none of it should be used by anyone else, and the planet is made to self destruct.