Because of the Rule of Perception, whenever a character walks into an invisible force field, expect a brief flash of the field and a light-sabery crackle. The trope name is the Stock Phrase that often results, in an odd aversion of Not Using the "Z" Word.
Using Some Kind of Force Field allows you to save your CGI budget for more attractive spacecraft. See also Deflector Shields and Force-Field Door. The primary difference is that those tropes refer to the barriers, whereas this trope refers to the scene where someone is required to walk up and experimentally poke it a few times while reciting the required phrase (as above).
- Tower of God: Lero-ro's shinsoo barrier, which the characters have to cross. It is touched and discussed quite a bit.
- Typically, the AT Fields in Neon Genesis Evangelion are invisible to the naked eye, until an enemy attack smashes into them and results in a bright orange, octagonal ripple wave.
- In Yu-Gi-Oh!: Capsule Monsters, an invisible force field stops Joey from flying over a wall the heroes need to cross.
- Parodied in Fables when Kevin Thorn sets up a force field around himself. Bigby runs into it and exclaims, "It's like some kind of... I don't know what it is!"
- In one Pearls Before Swine strip, the crocodiles say this when they try to attack Zebra but run into his screen door.
- Played with in Antz where the "force field" is Saran Wrap covering picnic goodies.
- Lampshade-hung by Patrick in The SpongeBob SquarePants Movie. The "force field" being a glass fish bowl, but still huge compared to SpongeBob and Patrick.
Patrick: It appears to be a wall of psychic energy.
SpongeBob: No, Patrick. It's a giant glass bowl.
- The Return of the King (Rankin/Bass Productions version) has one of these generated by the Watchers and exaggerated from the book. ("Bless my soul! It's some kind of invisible barrier!") By using the phial of Galadriel, the field rolls back like doors in response to sparkly magic. Note that in the book, the Watchers merely sapped the will of anyone trying to pass through; the barrier was more psychic than physical.
- In Wreck-It Ralph, there's no visible boundary at the entrance/exit of the Sugar Rush game, but when Ralph tries to drag Vanellope past it, a multicolored force field looking somewhat like plastic wrap stops her on the spot, since she's a glitch.
- Averted in Time Bandits, where the invisible barrier surrounding the Fortress of Ultimate Darkness is hard, and shatters like glass to reveal what's really behind it. "So this is what an invisible barrier looks like!"
- Played with in Suburban Commando, where the alien Shep Ramsey thinks that a mime, who is doing "the wall", is actually trapped in a force field. He tries to rescue the mime by punching through the field and ends up punching out the mime.
- Used to dramatic effect in Forbidden Planet, where an invisible monster attempts to break through the force field the crew have set up: they can see the flash caused by something trying to break through, but that's all they can see.
- In the Dungeons & Dragons movie, the main party (which includes a mage) encounters a Wall of Force spell. The mage, who should know about these things already, proclaims "It's some kind of wall of force!"
- Combined with Not Using the Zed Word in Independence Day. As soon as the first wave of missiles splashes uselessly against the alien ships' force fields, Will Smith's character yells out "they must have some kind of protective shield over the hull!" However, everyone immediately knows what that means and casually calls them shields afterward.
- In Zardoz, Zed (Sean Connery) simply presses up against the "invisible wall", i.e. a glass panel between him and the camera. No sparks, but the way it smushes his face and palms reveals the barrier's presence.
- The mushroom ring around the house in The Spiderwick Chronicles. Whenever anything other than a human tries to pass through it, they comically bounce off the magical barrier.
- Donny Darko from Donnie Darko encounters one in his bathroom. Except it's a hallucination. Well, maybe. He does the logical thing: Stab it repeatedly with a butcher knife while sporting a slightly deranged Kubrick Stare.
- Marvel Cinematic Universe:
- Played straight in the opening to Avengers: Age of Ultron. The force field around Baron Strucker's base isn't visible until Iron Man flies headlong into it.
Iron Man: Shit!
Captain America: Language!
- Thor: Ragnarok: When Thor tries to leave the Hulk's abode, despite the latter's warning that he's going nowhere, he walks straight into an invisible force field that blocks the hallway. The force field flashes with red intricate motifs similar to those of the rest of the room, and gives Thor a shock strong enough to stun the Asgardian.
- Avengers: Infinity War: Although the domed force field over Wakanda City is already visible as a faint blue glow, Proxima Midnight tests it out with the tip of her sword, making it brightly crackle, while awaiting Captain America and Black Panther for a face-off.
- Played straight in the opening to Avengers: Age of Ultron. The force field around Baron Strucker's base isn't visible until Iron Man flies headlong into it.
- The shield dome used by the aliens in Battleship can be seen from the outside, especially since it cuts through the clouds. However, a naval fighter jet still ends up slamming into it moments after it goes up.
- In Under the Dome, an enormous force field surrounding the town of Chester's Mill is discovered when several cars and a small airplane crash into it.
- In Star Trek: Deep Space Nine Millennium trilogy, several characters trapped in a bad future are surprised that the new-model confinement fields don't "emit Pauli exclusion sparks", Lampshade Hanging the frequency of this trope in Star Trek.
- Gaithim's barrier around the Crown in The Quest of the Unaligned is invisible until someone touches it, at which point it turns into a wall of lighting. This may be a deliberate design feature, given that it functions more like a booby-trap than a conventional forcefield.
- The Hunger Games: Prominent in Catching Fire, causing death or serious injury multiple times.
- In the Star Darlings book Stealing Starlight, Vivica projects a negative energy force field to keep the Star Darlings away from her and her Wisher.
- In every Star Trek series. Consistently accompaniend by a sparkly effect and a static crackling sound.
- In the Star Trek: The Original Series episode "Spectre of the Gun", when Kirk et al. were trapped inside the O.K. Corral.
- Averted in Deep Space Nine: The Dominion force field is lethal, so nobody touched it to make the obligatory shiny spot. It's a strange effect when they don't do it: without that little flash to aid Willing Suspension of Disbelief, it feels like they're just sitting on a platform that they could just step off of. Which, perhaps, they could have: they had only the word of a Dominion spy about its lethality, or that there was even a force field there at all... One wonders why they wouldn't spit at it to confirm the field is really there.
- 3rd Rock from the Sun's invisible box averts the visual aspect of the trope, but plays the characters' reactions straight. "My God! He's turned me into a mime!"
- Buffy the Vampire Slayer:
- The series has invisible barriers that prevent vampires from entering residences uninvited. An Angel episode shows Angel leaning against one of them, causing a slight ripple upon impact.
- The barrier that kept the Master imprisoned in Buffy season one also makes a rippling effect.
- In season five, Willow casts a spell to imprison Glory by thickening the air around her into tar, causing little ripples as she touches it.
- Doctor Who:
- The trope is subverted in "The Five Doctors" when the 2nd Doctor and the Brigadier find the former companions, Jaimie and Zoe, unaccountably in the Death Zone with them and frantically telling them to turn back. They claim that they are trapped by a forcefield and any disruption of it would kill them, so the heroes don't dare try to reach out to them to see the field. However, the Doctor, after trying to find a way to free them, realizes a basic fact, that those kids' memories of their time with him were erased, and simply steps forward where the field is supposedly in place. It turns out there was nothing and those companions vanish as the holographic decoys they really are.
- In the new series episode "Smith and Jones", the Doctor gets this effect when he throws a rock at the forcefield.
- The same thing happens in "The Hungry Earth" with the dome forcefield created by the Silurians.
- In "The Snowmen", the force field created by Jenny glows red whenever the Ice Governess slams into it.
- Stargate SG-1: Several varieties of force fields appear in the series, with various visual effects revealing their presence. Most of them are indeed invisible unless touched, but the results of a contact are quite variable.
- In "Upgrades", the Goa'uld force fields inside a ship in construction glow blue and looks somewhat like frost on windows when touched — or when going through at Super Speed thanks to the Atoniek armbands.
- In "Deadman Switch", Daniel Jackson walks nose-first into a red-glowing force field, put in place by Aris Boch to capture SG-1. Later in the episode, Teal'c is encased in a smaller version of the same field used as a detention device, and "knocks" on it to show the audience it's there.
- In "Windows of Opportunity", a force field surrounding Malakai and the Ancient control device doesn't just glow when hit: a mere contact propels Teal'c backwards and knocks him out. When the team tests the field again by throwing a stone at it, it shoots back with the speed of a bullet.
- In "The Other Guys", SG-1 is imprisoned in a force field that glows bright white on contact — as well as giving a serious shock when touched, if O'Neill's reaction is anything to go by.
Jack O'Neill: Don't touch this...
- In "The Ties That Bind", the scene is actually a Throw It In!: when Daniel Jackson tries to touch the power coil that is passed off as a religious artifact, he finds out it's protected by a small anti-thief shield which zap his fingers. That wasn't scripted, but the special effect was nonetheless added in post-production.
- In "The Road Not Taken", Mitchell walks into a lab, where Carter is experimenting on Merlin's device and smacks his head onto an invisible shield. Carter tries to warm him but doesn't manage it in time. She points out that she put up a sign outside the lab, only for Mitchell to take that sign from her desk, indicating she forgot to actually put it up. The shield is invisible, except when Mitchell walks into it or when it engages/disengages.
- Downplayed in the series version of Under the Dome. The eponymous dome is invisible unless seen in very wide-angle shots. Direct contact only cause a slight iridescence on the touched zone. It also gives a static shock the first time it's touched, but afterward only tingles a bit. Although it's dangerous to do so while carrying any electronic devices, which tend to blow up. The presence of the dome is quite obvious from plenty other hints, though, like the deep gouge it left in the earth. Or, the cow who was sliced in half because it had the bad luck to be right on the Dome's line.
- In season 3 of Hero Corp, John gets trapped in a cabin surrounded by a forcefield, normally invisible but looking like a Beehive Barrier when touched. This leads to two such scenes, first when John is testing it, and then when Mique tries walking through the forcefield and smashes his head — thrice in a minute (because he's a moron with the memory of a goldfish).
- Space: 1999. The episode "The Metamorph" has a classic Force-Field Door for the prison cell on the planet Psychon. Normally invisible, it emits a brief flash that stun the prisoners when touched.
- On Agents of S.H.I.E.L.D. episode "The Asset" Quinn has a neodymium laser force field surrounding his compound which vaporizes anything that touches it. It is invisible until something touches it; then it appears as a bright gold/yellow grid pattern.
- When the protagonists of The World Ends with You run into invisible walls, a Beehive Barrier can be seen.
- Barrow Hill has a variant that ripples when touched, even more like water than the one the picture above.
- The Legend of Zelda: The Wind Waker had one set up at the back of Hyrule Castle. A swipe of the Master Sword would break it like glass.
- Walking into a magic barrier in Risen leads to your character saying "It appears to be some sort of 'magic barrier'."
- In Persona 4: Arena, you know a character has run into an invisible wall because a distinctive sound plays and there is a white flash.
- In the Omega DLC for Mass Effect 3, Shepard dutifully utters the page quote when encountering the Cerberus force fields.
- In Flander's Company episode "Unlimited", the force field protecting Caleb's latest invention is indeed visible only when Hippolyte fires a Hand Blast at it. Nadège says (the French equivalent of) the trope name afterward.
- This is pointed out in Seanbaby's review of Superfriends as Superman's other weakness.
Besides kryptonite, Superman's main weakness was forcefields. He HATED forcefields. There are episodes made up entirely of Superman ramming himself headfirst into a forcefield over and over.
- In American Dragon: Jake Long season one episode four, the teeth minions try to run into the Long's apartment but are blocked by a Deflector Shield Jake's grandpa had set up earlier. The bad guy of the episode (a dentist) then proceeds to say, "What? It—It's some kind of shield!"
- Averted in Xiaolin Showdown. When the heroes are stuck dealing with the villain du jour, a magical mime, he traps most of them in an invisible box (marginally similar to the Third Rock from the Sun example above). There's no indication of its existence, and indeed, they don't realize there's a wall until they run into into it. From then, the only evidence that there is a box is people smacking into it and the outline of the kicked-up dust. Of course, the thing was shaped like however you think it is. The Stock Phrase half of this trope ends up being spoofed, as when Clay finds the others in the box and can't hear them (it's soundproof at the time), Raimundo uses charades to goad him into walking into the barrier and then mocks him for doing the usual routine:
Clay: [Rai points to himself] You. [points to his rear] Butt. [kicks] Kick. [points to Clay] Me. Raimundo's gonna kick my — HEY!
Dojo: Oooh, Five yards for unnecessary roughness.
Clay: Mister, you done made me mad. I'm gonna— OOF!
Raimundo: [as Clay investigates the force field] "Iiit's... some... sort... of... in... vii... sii... bullll... bahhhhhhhx." Ai, took him long enough.
- The Simpsons: Mr. Burns believed he had encountered "some kind of force field" when reaching for food at a cafeteria. It was a plastic sneeze guard.
- When The Penguins of Madagascar attack a killer whale balloon thinking it's a real whale and bounce off, Kowalski remarks that "the creature appears to be protected by some kind of blubbery force field. Also, Whee-hee-hee-hee!"
- Lampshade hung by Skeletor in an episode of He-Man and the Masters of the Universe (2002), after Tri-Klops has just crashed a vehicle into one.
Tri-Klops: Ugh... force field.
Skeletor: How intuitive.
- Happens ridiculously often in Danny Phantom, usually with added electric shocks. Danny is understandably not very fond of this one.
Danny: We've gotta find out what's going on in that hospital!
Tucker: Have fun, dude.
Danny: Tucker, I said "we".
Tucker: You also said "hospital".
Danny: Pfft. I turn invisible, I go ghost, I'll be in and out in no time! Watch!
[cut to Danny flying towards hospital, gets zapped by ghost shield]
Danny: GYAAAH!! [gets blasted into ground]
Tucker: Maybe we could come back during visiting hours.... Or, you know, not at all.
- My Little Pony: Friendship is Magic: In episode "Ponyville Confidential", the Cutie Mark Crusaders experience walking snout-first into an invisible force field (all three of them one by one, because of delayed reactions) when Twilight Sparkle doesn't want them getting into the library.
- Superfriends had this as a recurring problem for the team, particularly Superman, to the point where it seemed like his secondary weakness.
- In Brother Blood's second appearance on Teen Titans, the force-field around his tidal wave-generator is invisible until Cyborg walks into it. During their fight, Blood pins Cyborg against it, shocking him painfully.
- Mist nets, made of threads too fine to reflect sound, are this trope for the echolocating bats they are designed to snare.
- Assuming you haven't concussed yourself (or worse, lacerated yourself), it's a fun quip to follow walking into a glass door.