A 1987 film directed by Gary Goddard and based upon the franchise of the same name. The movie features Skeletor acquiring the Cosmic Key, a teleportation device from Gwildor, an eccentric inventor, which gives him an edge in his war against He-Man. Eventually the heroes find an identical device and use it to escape capture, accidentally traveling to a distant planet — Earth. Skeletor is not far behind. Starring Dolph Lundgren as He-Man and Frank Langella as Skeletor, Meg Foster as Evil-Lyn and a young Courteney Cox and Robert Duncan McNeill as teenage sweethearts Julie Winston and Kevin Corrigan, who are caught up in the events.A fictionalized version of the making of the live-action film was later used as the basis for a story arc in Paul Chadwick's Concrete. Additionally, there's no Prince Adam in this version, only He-Man, which is accurate enough; Adam originally didn't exist in the toyline or the (pre-Filmation) mini-comics that came with them.
Adult Fear: Kevin and Julie are pursued by ruthless mercenaries and have almost no adult figures to help them, as Julie's parents are dead and Carl is brutalized when he tries to help. It's a very good thing they run into He-Man.
Bald of Evil: Blade has a shaved head. Again, also Skeletor.
Big Entrance: He-Man, when he first arrives on earth. Skeletor and his army made a pretty big entrance themselves when they first arrived on the scene. In fact, Skeletor loves this trope, as he makes many entrances in this film often with low camera-angles and up-beat, dramatic music.
Julie, when she realizes that she gave the Cosmic Key to Evil-Lyn, who was disguised as Julie's mother at the time.
Evil-Lyn when He-Man manages to snatch the key back from her (although he's captured not much later).
If you listen closely, you'll find Skeletor is doing this rather than simply screaming during his Disney Villain Death at the end.
Canon Foreigner: Kevin and Julie, The Movie used only the most immediate characters of the show, He-Man, Duncan (Man-At-Arms), Teela and the Sorceress are the only heroes with a sidekick being a hairy gremlin called Gwildor (who vaguely fills out Orko's role in being comic relief, although he is also a Mad Scientist who is responsible for the plot). Skeletor, Evil-Lyn and Beast Man are the only villains with a group of improvised minions to fill out his ranks, in particular an eyepatch-wearing bald swordsman named Blade who sort of fills the role of The Dragon. They both got action figures in the toyline, but no attempt has ever been made to integrate them into any main canon.
The commentary track on the DVD sheds a lot of light on why The Movie lacked certain key characters from the franchise and why other characters were so drastically altered (notably Teela and Duncan). Suffice it to say, they had only a little money (most of it spent building the insanely elaborate Grayskull set they only barely got to use) and an extremely limited amount of time to film things. (The track also explains the presence of the mysterious pig-faced boy in the Grayskull throne room.)
An urban legend, popularized by 4th World fan (and comics pro) John Byrne, was that the movie was a Spiritual Licensee to Jack Kirby's Fourth World, with Skeletor taking the role of Darkseid and other characters (including the ones created for the movie) having a surprising correlation to each other. Read here for the full story. The director has admitted to being a fan of the comics, but he still tried to make a legitimate MOTU movie.
Blade and Saurod (a reptile-man mook introduced in the movie) made appearances in the comic book continuity, making them Canon Immigrants of a sort, despite Saurod getting killed by Skeletor in the film. Possibly however they were following on from the movie's comic book adaptation, which did not include Saurod's death. Blade and Gwildor also both received toys in the original toyline.
Much later, Gwildor and his invention were introduced into the mainstream He-Man story. Blade was integrated into mainstream continuity by way of his Masters of the Universe Classics toy bio.
Cape Swish: Skeletor appears to have a fetish for this.
Cold-Blooded Torture: Averted. Blade would prefer to "persuade" Kevin with his knives, but Evil-Lynn more sensibly opts for using some kind of mental manipulation collar that pacifies him and forces him to speak the truth. While this is shown to be rather mentally uncomfortable and painful to Kevin when they're putting the collar on him and later when his friends are breaking it off, it apparently has no lasting harmful effects.
Contest Winner Cameo: In the DVD Commentary, Gary Goddard mentions how Mattel held a contest where the winner would get a role in the film, but they didn't tell them about this until very late in production, so the winner just got a cameo as one of Skeletor's guards near the end with his face hidden under a pig mask.
Could Have Been Messy: An In-Universe and out-of-universe example. When the mercenaries are pursuing Julie, they come very close to hitting her with their blades and projectiles several times, even as Karg is yelling at them not to kill her because they need her alive for questioning. Then all this mayhem manages to touch off an electrical fire on the stage in the gym, from which she narrowly escapes. According to the director's commentary track on the DVD, the fire in this Trash the Set moment was quite real—albeit controlled—and the filming crew came dangerously close to burning the whole building down for real when the fire momentarily got out of hand. Mercifully for everyone, they managed to contain it before it did too much real damage.
Curb-Stomp Battle: Skeletor's forces at the beginning lay one on the Eternians offscreen, resulting in most of the Eternian military being either killed or captured.
Genre Savvy: Evil Lyn. Skeletor monologuing an A God Am I speech? Heroes mounting their final desperate resistance against impossible odds? Time to leave. If you watch her facial expressions, you can see her concern mounting throughout the scene.
A God Am I: Skeletor has one of these speeches at the climax, right down to the line "I am a god!"
He does show some signs of being a Physical God, albeit hardly an omnipotent one.
Great Offscreen War: Right before the events of the film Skeletor's forces have taken Castle Grayskull and He-Man, Man-At-Arms and Teela are practically fugitives.
Jerk with a Heart of Gold: Well hey, he does actually do his job in helping Kevin look for his girlfriend even if he's a bit of a dick about it; and he's perfectly happy with his reward of a lovely woman and a cushy retirement on Eternia at the end.
Kneel Before Zod: Skeletor becomes a god and demands He-Man kneel before him, using magic to force him to his knees.
Knife Nut: They don't call him "Blade" for nothing.
Left the Background Music On: The soundtrack swells as Kevin tries to remember the Cosmic Key tune to get them to Eternia and finally shouts, "I can't hear myself think. I wish someone would turn that thing off", indicating the music coming from the loudspeaker in the park. On cue, Teela blasts it.
Magic Music: How the Cosmic Key works, basically uses a type of Functional Magic that works via music: playing certain notes on the instrument much like dialing a telephone causes a spell-like effect to happen. Thus sending the dialer wherever they wished to go. Near the end of the film Kevin is somehow able to replicate the effect using an ordinary keyboard synthesizer.
Master of Illusion: Evil-Lyn can turn into just about anyone she wants with this power, she used it twice in the film. Once on Gwildor (off screen) and again on Julie.
Mecha-Mooks: Skeletor's "crack troops" are a bunch of black-armored robots.
Hardcore fans have supposed that the plot could actually work within the cartoon's timeline, assuming Skeletor killed Hordak and stole his limitless armies.
Muggles Do It... Competently: Though Earthlings are outgunned because the technology of Eternia is clearly more advanced than Earth's, it appears to derive from similar sources and be fairly easy to master with native technical skill. One scene demonstrates this in that a microwave Kevin happens to be using interferes with the bad guys' scanners (just as it has been known to interfere with our own radio, television, and wi-fi signals). Kevin is able to operate the musical key effectively once Gwildor helps him hook a Casio keyboard from the local music shop up to it, and in one rather entertaining scene, Lubic demonstrates that good old-fashioned shotgun slugs work just as well on those Mecha-Mooks as any of Eternia's energy weapons.
Julie, upon realizing that she handed the Cosmic Key over to Evil-Lyn
No Plans, No Prototype, No Backup: Subverted to hell and back. Skeletor and Evil-Lyn assume that they have the only Cosmic Key after she stole it from Gwildor, but he had a prototype model that he hid from her, thus allowing the Eternians to have a fighting chance of defeating Skeletor.
Tracking Device: The Cosmic Key has one, of a sort. When the large red button is pushed, it sends out a unique energy signature than can be tracked.
Within a parsec-eon.
Trapped in Another World: After it changes hands several times, Skeletor finally wrecks the device the Eternians need to get home, thereby forcing them to stay on Earth. Since he underestimates the Muggles as usual, however, he makes the mistake of leaving the damaged device and its inventor in the middle of a moderately technologically advanced civilization along with all the heroes except He-Man. Between them, they have all the parts they need to fix it, and somebody who can figure out how to set it to transport them directly into Grayskull's throne room.
Treacherous Spirit Chase: In the movie, Julie immediately accepts her dead mother turning up in the middle of a siege by magic aliens from another dimension to lure her out the back door of the shop in which she and her friends are holed up defending a powerful alien artifact. Moments later, she accepts that her dead mother needs her to hand over said artifact. Needless to say, it's not really her dead mother.
Too Important to Walk: Skeletor arrives on earth sitting comfortably atop one of his intimidating-looking hover-thrones.