History Main / PortalSlam

** Though not quite the same, Earth's stargate in ''Series/StargateSG1'' has an item known as an "iris" that can be closed over the portal, which prevents most physical matter from fully manifesting itself on Earth's side of the wormhole if the bad guys decide to use it in an invasion attempt. Captain Carter says "It doesn't even allow matter to reintegrate", but stuff still comes through as atoms -- it just doesn't have enough room to reassemble itself into molecules or Jaffa. This is used to provide less-advanced allies who couldn't figure out an IDC with a primitive one-time method of contacting SGC: Throwing a box containing iridium through the gate allows traces of the element to be detected on the iris. That same property unfortunately allowed other forms of energy to present a threat to the SGC despite the iris: hard radiation, energy weapons, and a black hole all presented dangers that the iris could only dampen, not completely stop.

** A lethal variant is used on Atlantis when John Sheppard raises the gate force field as a platoon of Genii assault reinforcements are coming through. He knocks out the only person guarding the gate controls, then raises the shield after only 5 out of 60 soldiers have come through, dooming the rest to slam against the force field as bursts of energy.

* ''WesternAnimation/MonstersInc''

* A RunningGag in ''Series/LetTheBloodRunFree'' is to have special effects allow characters walk down a corridor that's clearly painted onto the background. If Matron Conniving Bitch tries to follow them, she'll just walk into the wall.

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[[quoteright:320:[[Webcomic/StarPower https://static.tvtropes.org/pmwiki/pub/images/starpower_portalslam.png]]]]

[[folder:Anime]]

* A recurring plot point in ''Manga/{{Doraemon}}'' have this happening either to the [[TheLonelyDoor Anywhere Door]] or TimeMachine, which leaves Doraemon and gang stranded in a different locatiom or timezone. One note-worthy example in a manga chapter where the gang travels back in time to investigate the myth of Urashima-Taro, only to be captured by a hostile underwater kingdom; by the time they escaped, [[OhCrap they realized a tree had unexpectedly grown on the spot where the machine's portal was, swallowing it]].
* ''Anime/DoraemonNobitaAndTheSteelTroops'' had Nobita and Doraemon escaping through a PortalPool (leading from mirror-dimension Tokyo to the ''real'' Tokyo) as the steel troops, led by HumongousMecha Zanda Claus, pursues them, with Zanda Claus who's too big to fit through forcing the portal open, resulting in a ''massive'' explosion caused by the portal collapsing that nearly buried Doraemon and Nobita alive. On the plus side, the portal is now momentarily sealed, keeping the steel troops trapped in the mirror world.

[[folder:Films -- Animation]]

* ''WesternAnimation/ThePhantomTollbooth'' (the movie, not the book) eats itself after Milo goes through it.

* At the end of ''WesternAnimation/TheLegoBatmanMovie'' when Batman is ascending into the Phantom Zone, he hits an invisible barrier and falls because of his actions in the film's climax, Phyllis no longer sees him as a villain.

* A famous scene from ''Film/AustinPowersTheSpyWhoShaggedMe'' has Dr. Evil running into his ''un''activated portal-style time machine, only to smack into it.

* In ''Film/TheAdjustmentBureau'', the Adjusters have the power to use any door as a portal. Similar to ''Franchise/TheMatrix'', the portal disappears when the door is closed.
* In ''Film/{{Parking|1985}}'', Orpheus attempts to enter the Underworld the same way Charon's car did and crashes into a solid wall, wrecking his motorcycle.
* In the original ''Film/{{Stargate}}'' movie, Jack O'Neil, Daniel Jackson, and their team go through the gate to Abydos with the expectation they'll be able to go back to Earth right away. Only problem is, Daniel was expecting the gate address for Earth to be written down somewhere in the same room as the gate.

* Harry and Ron rebound painfully from the sealed gateway to Platform 9¾ in ''Literature/HarryPotterAndTheChamberOfSecrets''.

* In ''Literature/ThePhantomTollbooth,'' Milo finds the morning after that the tollbooth has vanished, with a note in its place that explains that the tollbooth will find its way to the next needed child.
* ''Literature/TheChroniclesOfNarnia'':
** The doorway in the wardrobe into Narnia vanishes when Lucy tries to show it to her siblings the first time. A portal to Narnia only seems to appear when you're not looking for it, according to Professor Kirke -- and indeed, in Creator/CSLewis's other Narnia books, every portal only works once, as opposed to the three times the wardrobe does.
** Used again in ''The Magician's Nephew'', with an actual splash; Digory and Polly jump in a pool that they know is a magic portal and only get their feet wet. In their case, though, the portal still worked; they just weren't using their magic rings correctly (as they quickly figured out).

* Princess Quinn of Dian Curtis Regan's novel ''Literature/PrincessNevermore'' attempts to return to her homeworld by leaping back into the pond she emerged from. All she gets is soaking wet. The spell must be reactivated [[spoiler: by spinning around to generate a vortex]] before she can return.

* Variation from ''Literature/InTheKeepOfTime'': since it isn't possible to "splat" against a portal which consists of simply opening a real door, the children are instead kept from traveling through time by the need to warn the men of the English ambush, then by the key's disappearance. Although the magic of the key comes and goes, this turns out to be a RedHerring and not a ChekhovsGun, as it seems that once "unlocking" a time period, the key remains ready to use until the bearer returns to their own time. Something of a TheyWastedAPerfectlyGoodPlot moment, although subverting reader expectations here was also clever.
* Cowl forces this on Harry and Lara in the ''Literature/DresdenFiles'', just as they were about to escape the C4-rigged cave.

** [[Recap/DoctorWhoS27E8FathersDay "Father's Day"]]: Disruptions in time cause the interior of the TARDIS (which is, of course, bigger on the inside than on the outside) to vanish, leaving only the police box shell. No, don't ask how this makes sense. At least it makes more sense than the original idea: it was supposed to FALL APART.
*** It also makes more sense than a similar scene in [[Recap/DoctorWhoS2E9TheTimeMeddler "The Time Meddler"]]; when the Meddling Monk's TARDIS had its dimensional controls removed, the console room ''shrunk'' to fit the exterior shell!
** [[Recap/DoctorWhoS28E4TheGirlInTheFireplace "The Girl in the Fireplace"]] has time portals between a futuristic spaceship and 17th century France. One portal the Doctor uses is attached to a mirror, which breaks on the way through and won't let him back in. The title fireplace is another (malfunctioning) portal, but while time passes normally on one side years pass between each trip on the other, with more than one serious plot consequence.
** In [[Recap/DoctorWhoS34E9Flatline "Flatline"]], aliens from a two-dimensional universe cause the Police Box disguise of the TARDIS to shrink without likewise affecting the internal dimensions. The result is that the TARDIS shrinks to the size of a toy and the Doctor cannot fit through the opening. Clara instead sticks the box in her purse and the Doctor passes objects through as needed.
* One episode of ''{{Series/Farscape}}'' has WesternAnimation/LooneyTunes-style Crighton (ItMakesSenseInContext... [[MakesJustAsMuchSenseInContext sort of]]) paint a wormhole on a brick wall, which works fine for him but causes his pursuer to crash into it like Wile E. Coyote.

* A Portal Splat was used to remove Mr. Marshall from ''Series/LandOfTheLost1974'' when the actor playing him wouldn't come back for the third season. Fiddling with the controls of a pylon, he opens a portal and slips through, but a tremor knocks the control-pedestal over, causing the portal to vanish before Will and Holly can follow him.

* ''Series/MirrorMirror1995'' has a portal that only works when both ends are in alignment. Also, it refuses to allow certain people through, to the point of ''shocking'' them. [[spoiler:At the end of the show, Nicholas chooses to stay and Louisa returns to 1919, thus negating every single event the Old Man worked to bring to pass, thus the Mirror erased itself from the "present day" timeline.]]

* In the final episode of the original ''Series/TheTwilightZone1959'', kids who jump into a pool emerge from a pond, to live with a nice old woman. Once the kids do this, they can hear their parents arguing become fainter and fainter, implying the portal is closing.

* Happens at the end of the main story mission "What Pride Had Wrought" in ''VideoGame/DragonAgeInquisition''. When the Inquisitor's party escapes the Temple of Mythal through an eluvian, Corypheus tries to follow, but the portal closes in his face, resulting in him slamming into the mirror at high speed.
* One of the main quests in ''[[VideoGame/{{Avernum}} Avernum 2]]'' is destroying Empire's portal through which it sends reinforcements and supplies to Avernum.

* ''Webcomic/StarPower'': In [[http://www.starpowercomic.com/comic/inches-and-lightyears-away/ this]] strip, a Gate has been opened, and then closes while Sanchez was trying to enter. [[spoiler:By Star Power, who had no idea he was trying to go through]].

** Wile E. Coyote's experience probably qualifies. He's repeatedly painted a tunnel on the side of a wall, seen the Road Runner inexplicably go through the tunnel as if it were a real one, and then tried followed it through the painted tunnel, only to run smack into the wall, usually accompanied by a literal 'splat' sound.

* No less than three incarnations of ''Franchise/TeenageMutantNinjaTurtles'' have told the story of an artist based on Creator/JackKirby, whose [[ArtInitiatesLife drawings created a parallel universe]] that he and one of the Turtles must save. The portal stays open long enough for the Turtle to return home... but not Kirby.
* ''WesternAnimation/{{Teenage Mutant Ninja Turtles|1987}}'':
** The 1987 animated series does this frequently, to the point where it's lampshaded after the Big Bad and his mooks escape through a portal that closes before the good guys can follow: "How do they get away EVERY time?"
** The first episode of the second season had the most famous instance of a Portal Splat. When Krang agrees to send Shredder back to Earth, the portal opens and he dashes through; but when Rocksteady and Bebop attempt to follow, the portal closes on them, and the two of them rebound off the surface of the portal mechanism itself.
* Hsi Wu, the Sky Demon in ''WesternAnimation/JackieChanAdventures'', attempts to exit the Demon Netherworld using Shendu's portal after Jade goes through it, disregarding the rule that only one person can use a portal when it opens. Sure enough, the portal closes and Hsi Wu slams into a floating rock formation that happens to be behind the location where the portal manifested.
** A variant in "A Night at the Opera". The villains use a magic makeup to be able to pass through walls. Just as one of them tries to make their escape, Jade splashes him with water and he crashes into a wall.
* In one episode of ''WesternAnimation/TheGrimAdventuresOfBillyAndMandy'', Billy's kiddie pool is accidentally turned into a Cosmic Sinkhole, which basically functions as an inter-dimensional portal. Whenever [[TheBully Sperg]] tries to use it, he just hits the bottom of the pool.

** Boo finds only an ordinary closet instead of a portal to Monstropolis after Sully and Mike are obligated to let the closet door be destroyed. Earlier, the same thing happens

* In ''Film/TheHitchhikersGuideToTheGalaxy2005'', Arthur is afraid to go into the portal at Magrathea after the others. By the time he gets up the nerve and runs at it full speed, the portal is inactive and he ends up sliding through it.

* In ''Film/Parking1985'', Orpheus attempts to enter the Underworld the same way Charon's car did and crashes into a solid wall, wrecking his motorcycle.

** A lethal variant is used on Atlantis when John Sheppard raised the gate force shield as a platoon of Genii assault reinforcements were coming through. He drops the shield, kills a couple of of the soldiers waiting at the gate, then 50 of the Genii soldiers are obliterated one by one with nothing more than a audible splats on the shield.

* The Australian TV series ''Series/MirrorMirror'' has a portal that only works when both ends are in alignment. Also, it refuses to allow certain people through, to the point of ''shocking'' them. [[spoiler:At the end of the show, Nicholas chooses to stay and Louisa returns to 1919, thus negating every single event the Old Man worked to bring to pass, thus the Mirror erased itself from the "present day" timeline.]]

* https://www.youtube.com/watch?v=WEFWRzzAp3E

* A Portal Splat was used to remove Mr. Marshall from ''Series/LandOfTheLost'' when the actor playing him wouldn't come back for the third season. Fiddling with the controls of a pylon, he opens a portal and slips through, but a tremor knocks the control-pedestal over, causing the portal to vanish before Will and Holly can follow him.

[[folder:Films — Animation]]

[[folder:Films — Live-Action]]

* In Creator/DeanKoontz's ''Lightning'', any [[spoiler: time traveler]] attempting to make a "jaunt" that would result in [[spoiler: a temporal paradox]] is violently "bounced back" to the point from which the jaunt was originally attempted.

* Vortices disappearing when people try to jump through them happens an awful lot in ''Series/{{Sliders}}''. If it's a good guy, they'll always find another vortex. If it's a bad guy, they're usually trapped until the good guys can deal with them. Rickman, the BigBad of season three, meets his end this way when a portal is just over a cliff. When it shuts down just as he's leaping for it, he falls to his death.

** Though not quite the same, Earth's stargate in ''Series/StargateSG1'' has an item known as an "iris" that can be closed over the portal, which prevents most physical matter from fully manifesting itself on Earth's side of the wormhole if the bad guys decide to use it in an invasion attempt. Captain Carter says "It doesn't even allow matter to reintegrate", but stuff still comes through as atoms -- it just doesn't have enough room to reassemble itself into molecules or Jaffa. This is used to provide less-advanced allies who couldn't figure out an IDC with a primitive one-time method of contacting SGC: Throwing a box containing iridium through the gate allows traces of the element to be detected on the iris.

* In the film version of ''Film/TheHitchhikersGuideToTheGalaxy'', Arthur is afraid to go into the portal at Magrathea after the others. By the time he gets up the nerve and runs at it full speed, the portal is inactive and he ends up sliding through it.

* Will almost certainly happen at least once during a play through of ''VideoGame/{{Portal}}'', since you're going to screw up and place a blue portal when you meant to place an orange one, or vice versa. Happens even more often during co-op play in [[VideoGame/{{Portal2}} the sequel]] once you realize that it's almost as much [[VideoGameCrueltyPotential fun to torture]] [[WhatMeasureIsANonHuman your teammate]] as it is to solve the puzzles.

[[folder:Web Comics]]

[[folder:Anime]]

A character tries to enter a [[CoolGate magic portal]], often at high speed, only to discover that it is no longer there. Maybe the magic has been sealed or the portal cannot be opened in the presence of {{Muggles}}, i.e. the character can't show it to his family or friends. Maybe the portal is an EmpathicWeapon that lets you through only when it's in the mood. Or maybe it technically does work, but the other end of the portal got moved right up against solid rock.

[[folder:Webcomics]]

* In ''Webcomic/{{Erfworld}}'', this one's invoked by Charlie and the Jetstone side, in order to trap Parson in an unwinnable situation. (More an emotional slam than a physical one: Parson was hoping to keep that portal open as an escape route.)
* ''Webcomic/StarPower'': In [[http://www.starpowercomic.com/comic/inches-and-lightyears-away/ this]] strip, a Gate has been opened, and then closes while Sanchez was trying to enter. [[spoiler:By Star Power, who had no idea he was trying to go through]].

* ''WesternAnimation/WileECoyoteAndTheRoadrunner'':

* In ''Webcomic/{{Homestuck}}'', [[http://www.mspaintadventures.com/?s=6&p=006531 God Cat unplugs one of Roxy's portals]], resulting in this.

** When Sully and Mike [[spoiler:are banished]], finding a big metal door in the middle of nothing.

* ''Film/RogueOne'' has a non-magical variation involving hyperspace. The Rebel fleet starts evacuating from Scarif's orbit once they've received the Death Star plans, but only a few ships make the jump before [[spoiler:Darth Vader's personal flagship, the Star Destroyer ''Devastator'', jumps into the system from the direction they're attempting to escape in, causing several Rebel ships to destroy themselves by smashing into it]].