The most extreme and egregious form of the Insurmountable Waist-Height Fence, the Invisible Wall is, well, just that: a boundary that limits where the player can go, but there's simply nothing there. It's as if someone decided to build a glass wall. You try to walk past it but your character just stops or walks in place. You can't see the boundary, but it's there.
In 2D games, the edge of the screen itself frequently served as the Invisible Wall, working on the principle of "out of sight, out of mind"; you can't go there, but as far as you can see there's nothing there anyway, so why would you want to? Then again, once the edge of the screen starts crushing you, questions may rise.
Depending on the capabilities of the Player Character and the geography of the game setting, some Invisible Walls may at times be Acceptable Breaks from Reality. Since the game world is necessarily limited in size, a level designer ultimately has to decide if simply forbidding a player from going out-of-bounds with a seemingly arbitrary block breaks Willing Suspension of Disbelief more than having the player walled-in on all sides. One way of averting this dilemma is use a natural Gravity Barrier, which is why islands in the middle of the ocean are such popular game settings.
When the invisible wall prevents you from walking past the edge of a platform, be it next to a Bottomless Pit or not, it's a case of Edge Gravity.
See also Gateless Ghetto.
Not to be confused with the Gametrailers podcast/show of the same name.
Used with and without explanation in City of Heroes; some urban missions are explicitly described as taking place in neighborhoods which have been isolated with portable forcefield units, but other urban missions, as well as tasks in the Spirit World, have transparent boundaries for no known reason. (And strictly speaking, these walls aren't invisible when you're close up to them; then they're transparent blue.) The "War Walls" separating the various zones serve a similar purpose, although they're visible and again have an in-game explanation.
Every outdoor area also has an Invisible Ceiling: you can only fly/teleport/etc. so high.
There are standard-issue invisible walls in the Training Area, with no explanation. Interestingly, they aren't tall enough: the Jump Pack power lets you jump over them, leading to things looking a bit... broken.
Rayman Origins oddly averts this in some levels; running off the screen to the left at the start or end of a level will eventually kill the player. But in this game, Death Is a Slap on the Wrist, so it doesn't really matter.
X-Men Legends has these everywhere, and usually without explanation.
In one episode of the game review show Reviews On The Run, Tommy Tallarico memorably breaks into a long rant about the invisible walls in Bomberman Jetters.
Kingdom Hearts tends to use these, with a camera shot whenever one shoots up behind the player inexplicably, but it's really just a flag to tell the player he's about to fight a difficult boss.
In KHI, though, Goofy and Donald bounce off invisible walls just before Sora fights the Duel Boss / That One Boss, Xehanort-Possessed Riku.
358/2 Days showed that this could be a blessing in disguise. It kept the "enemies heal when they disappear" mechanic KHII introduced, but not the "lock-on means you can't leave the area" mechanic, while several of its bosses don't use the invisible barriers. This means that you could be knocked out of an area by a particularly difficult boss's attack, only to return and find it fully healed.
Some of the later games introduce another variant: You can't go into areas you're not supposed to go to at the moment, and your character will remind you that it's not the right way.
However, the ultimate example is probably the first area in The End of the World. It is literally an entire invisible MAZE. As in, it is a huge empty area full of invisible walls. Your only clue of how to navigate it is that the walls tend to intersect at the random bits of rock, which you are not actually told, you have to figure it out by trial-and-error. Also, certain parts of this maze will feature equally invisible battles that you can't run from. Some treasure chests are booby-trapped and sometimes an odd orb of darkness will hit you even if you don't open any chests. Some of these battles are even against the mini-boss that accompanies the game's difficulty spike, the Behemoth.
The Elder Scrolls IV: Oblivion; should you come to the edge of the map, a caption will come on the screen telling you that you can go no further, which by then is perfectly obvious. Given you literally cannot go any further. Nevermind that the land and/or water continues, and you can see the terrain continuing into the distance, often with locations that would give you a strategic advantage over the enemies, or some rare plants with precious alchemy components just out of your reach. These border walls - unlike other invisible walls within the game - can be turned off with a switch in the game's .ini file. The area between them and the real end of the map is completely empty, consisting only of ground and vegetation. Similar to the "beauty strip" between a clearcut forest and a road, it exists only to mask the fact that at some point the world simply ceases to exist, cutting off in mid-air.
Within the game world, invisible walls are sometimes used to make certain obstacles, such as burning houses and steep mountainsides truly insurmountable, which becomes obvious when the player is buffed to superhuman skill levels far beyond what is achievable through normal means. Even though the player should be able to leap low buildings (even burning ones) in a single bound, they are stopped in mid-leap - ostensibly by an obstacle that, the 3rd person view shows, doesn't even touch them.
While passing most invisible walls only results in a glimpse of every layer of the art framework until its sudden end, crossing the invisible walls in certain places, such as in the painted realm, will eternally trap the character on the wrong side.
Interestingly, Morrowind didn't have invisible walls. The game world was an island; if you kept going in a straight line the ground would end, you'd start swimming, and if you persisted long enough you'd eventually find yourself on the other end of the island, because the game world wrapped around.
The mod "Oscuro's Oblivion Overhaul" does away with the invisible walls that form the world's boundary. There's nothing interesting on the other side, though; only an endless ocean or grassland.
Skyrim continues this trend, although there is usually a wall of mountains blocking access anyway. There are a few paths that lead into other provinces but are blocked by invisible walls, and this happens in the ocean too. A message on the top corner of the screen will bluntly state "You cannot go that way."
Motocross Madness has both a visible wall (in the form of high cliffs surrounding the arena) and an invisible cannon. Should you manage to scale the cliffs, you see an endless flat expanse, but driving more than a few feet into it gets you a free trip into the sky... for a few seconds. (Then you crater back into the arena)
In Halo 2, horizontal instant-kill barriers prevent the player from taking a shortcut from the top to the bottom of certain areas (for example, the elevator shaft on The Oracle), despite there being no fall damage in the rest of the game. Vertical "death walls" are also used, in addition to nonlethal invisible walls. They apparently forgot to patch up the holes in some places, though, eg. some seemingly insurmountable hills can be climbed, leading to major Sequence Breaking.
Invisible Walls keep you from plummeting to your death in any of Drakengard's dangerous looking chasms. You can fly over them with the dragon, but you sadly can't dismount into them.
Most strategy games have these at the border of the map. The more recent ones tend to show terrain beyond that point to make it less obvious and the map more realistic.
In Total Annihilation the player's inability to move the mouse pointer outside the world limit makes it impossible to order units off it. However, should you order bomber planes to attack an enemy object that's close to the limit, they'll cheerfully fly off it and come back raining death. They can't land outside the world, though; tell them to stop and they'll first come back, and then land.
Similarly, WarCraft 2 almost plays this straight, with the one exception of whirlwinds, which are able to move at least a short distance off the edge of the map and then return.
Europa Universalis has a variation of this: The map is spherical (but you can't travel to the poles) but certain areas are designated as "Permanent Terra Incognita" and cannot be explored (includes the interiors of Africa, Australia and the Americas.)
In Star Fox 64, during the "all-range mode" segments, reaching the edge of the map causes your ship to automatically turn around.
Super Mario 64 tells you about them with a sign, saying that's where the paintings end. Seeing as all of Mario 64's worlds are in paintings, it... kind of works.
Still, some gamers have encountered invisible walls in random, unexplained places not related to the edge of a world.
Diddy Kong Racing for the Nintendo 64 had a very noticeable example where you could barely get off the beach into the ocean before you hit it.
Family Guy: The Game lampshades this, with an unobstructed street where a mime is moving back and forth along an invisible wall. Trying to go around the mime prompts Peter to say "Stupid mimes and their invisible walls..."
In the N64 game Snowboard Kids, you could do a jump and veer off to the side of the track, then hit an invisible wall in the middle of the sky and slide right back down.
In the first Return Fire game you could pilot the helicopter off the main play area (always an island) and away in the distance. However, if you overdid it, a sub would surface right under you and shoot you with a homing missile that was absolutely impossible to evade and would kill you in one hit.
The Gundam Vs Series added these in Gundam SEED: Alliance vs. ZAFT, and for once it's actually a good thing. Past iterations of the series had the outer limits of the stage be a line that, if crossed, forced your Humongous Mecha to auto-pilot itself back into the stage, which was time-consuming, left you open to attack, and lead to a Most Annoying Sound ("You've left the mission area, please return!"). The use of Invisible Walls speeds up gameplay greatly, and they don't significantly reduce the size of the stages, so it ends up working out well in the end.
This is justified in The World Ends with You - the Reapers make the Reaper's Game more interesting by blocking off sections of Shibuya, forcing you to run as they want you to. Some of the walls are lowered by completing tasks assigned by Support Reapers - everything from defeating Noise in a certain fashion to bringing them food to answering a Pop Quiz.
Grand Theft Auto: San Andreas had a unique way of confining the player to certain areas of the game. Certain parts of the state are closed off to traffic with the use of barriers, but if you manage to go past the barriers (swimming, use of a boat, or flying a plane for example), you'll instantly get a high warrant level. Even if you use a cheat or the Pay n' Spray in the restricted areas, the warrant levels never go away until you go back where you're supposed to be. The barriers will disappear as you make progress in the storyline.
GTA 3 and Vice City had invisible walls in the ocean. If you kept trying to leave the city, an invisible wall would bring your boat or plane to a stop. San Andreas allowed the player to go as far as they wanted. However, the farther out you go will equal to the same amount of time it will take to travel back.
In Gothic, the magical barrier that surrounds the prison colony is largely invisible until you walk into it, at which point you are surrounded by crackling blue lightning. Keep walking, and you'll start taking damage and quickly die. Unsurprisingly, there have been no recorded escapes from this colony.
Wizardry VII has a whole city full of invisible walls. The city is inhabited by a race that flies, which is comparable to making a snake with wheels.
Sonic The Hedgehog 3 pulls the Invisible Wall at the first Launch Base Act 2 boss. You SHOULD be able to jump to that ledge but you can't, and until Robotnik jumps into his machine, you can't do anything to him. Annoying, considering that the invisible wall disappears once he's been defeated.
It's done for a reason though. Basically, the trigger for the cutscene is below, and if you get past the wall (easiest with lightning shield) the boss screws up and can't attack, and you can still damage him. Not to mention that killing off a machine before Robotnik has even went in is a bit silly.
It's possible to fly behind it with Tails while it's rising up, slip in behind him, and kill him there.
In Carnival Night Zone, when Knuckles appears to turn off the lights. Sonic just stops, inches away from the smirking echidna... held back by an Invisible Wall. Even worse, you can have all of the emeralds by this point, and so Super Sonic can be held at bay by it.
When you're taken into the past by a lens flare in Sonic Adventure, you may see these little structures that are basically a roof and four supports at the corners. You can't go under them. Perhaps this is because it's easier to define an object as being simply this high, that wide, and that long rather than defining all the details of the shape of that object, especially when there's no reason to do so. It's still a little strange.
Sonic Colors uses Invisible Walls in spades. They get annoying in 2D as they prohibit backtracking in some areas, but in 3D, they're really for the best: they line the stage so that the player doesn't fall into the Bottomless Pits unfairly.
As has been pointed out on several fansites, the levels are actually one mass. They are then divided into "acts" with goal rings and invisible walls. Its possible to get beyond them in some areas and see parts of other acts or blank objects.
World of Warcraft mostly averted this once Flying mounts came out with its two main maps, Kalimdor and the Eastern Kingdoms. However, this trope kicks in full force in Outland, and the Draenei and Blood Elf starting zones. In Instances, each of which is its own isolated mini-map, you aren't actually supposed to run into invisible walls (many of them are dungeons of some kind anyway), but they're still there as a backup, just in case you manage to actually surmount the Insurmountable Waist-Height Fence. Outland has invisible walls and an invisible ceiling for flying mounts.
There are certain Instances that DO have invisible walls, notably those featured in the Caverns of Time. These contain a replica of a present-day zone as it was at some point in the past. If you leave the standard play area, a mist forms around you, essentially warning that you can't go much farther. And then you hit the invisible wall, forcing you to turn around.
Instead of Invisible Walls, Warcraft mostly has invisible ceilings that are so high that you can't actually see the ground at that height anyway, and if you fly too far out into the sea you'll shortly die of Fatigue damage. The exception is the invisible wall over the mountain range dividing the Eastern Plaguelands and Ghostlands. This is because it would take up too much data to make the entire mountain range into an instance portal. Instead there is a portal at the gates through which you must go to get there. Even if you pay for a ride there, you still go through that gate.
Maybe we can put it down to the Blood Elves being such chronic magic users and the Draenei's magitech...
The Thief games have occasional invisible walls, but all in areas the player isn't supposed to reach (such as the roofs of buildings). However, these are notable in that they are apparently made of invisible wood, and as such the player can smash them aside with their sword and continue.
Al of the Star WarsRogue Squadron games will turn your ship around if you go too far outside the mission area. Sometimes it's explained (getting too far from the action), on others (like the infinite featureless plane of the Death Star endurance level) it feels a little limiting.
Assassin's Creed I has points where whenever Altair attempts to wander off somewhere he's technically never been to yet, a not-quite-invisible wall appears and blocks his path, along with a message from the Animus stating that he cannot go there YET!
Not only that, but the wall only blocks Altair if he attempts to walk into it at ground level. It's possible for Altair to cross over this wall at a higher point (say by momentum from Le Parkour off a nearby building) but the moment you land you will die.
In Space Quest I, the town of Ulence Flats is surrounded by a literal force field that prevents you from walking out (but doesn't obstruct airborne vehicles). Averted in other areas, where they use Border Patrol such as man-eating sand serpents to discourage going out of bounds.
Invisible walls are typically found at the edge of any outdoor area in Glider PRO. (Ironically, visible walls had to have invisible rebounder objects placed over them if they were in the middle of the screen.)
Fallout 3 has these in much the same way Assassin's creed does - try to walk off the map and a pop-up box will tell you something along the lines of "You cannot go any farther north."
Lampshaded in the Operation: Anchorage expansion, which takes place in a computer simulation. There are semi-visible walls showing you where you can't go in the simulation.
Infuriatingly, Fallout: New Vegas does this egregiously. Several mountain ranges that look like you should be able to jump over them just randomly won't let you. It's understandable when it's there to prevent Sequence Breaking, but in some areas it's pointless and completely arbitrary. Especially when they already have a perfectly good Beef Gate blocking me.
Kirby Air Ride has one around every course, a well as the city in City Trial mode.
The City Trail mode has an odd one, though. Though there are the normal invisible walls around the sides of the map, if you go at them from a high altitude you'll go through them. However, all you can do outside of the invisible walls is ride around on water, and if you continue going away from the city you'll reach another set of invisible walls which can't be bypassed. What's odd about the invisible wall system, though, is that in some places there are small ramps outside of the first invisible wall which will bring you back into the map instead of getting stuck at a wall, meaning the developers anticipated people bypassing the walls.
Magical Battle Arena marks the boundaries of the battlefield with a literal invisible wall: a pink grid-like magical barrier that only becomes visible when you touch it (or try to blow it up), and only that specific spot that you touch. It's visible on the HUD minimap, though.
Every combat map in Mount & Blade is surrounded by a perfectly rectangular one of these. The wall itself isn't invisible, but if you're sufficiently close to it, you'll notice an abrupt change in the texture of the ground, as well as the fact that you cannot walk or ride across this change in texture. It's encountered most often with the highly mobile horse-versus-horse encounters, since the slower infantry don't usually get very far from the center.
Prototype tries to avert this by having the military launch air strikes at you if you try to leave the quarantined island, but it's fairly easy to dodge them on foot while running across a bridge, which lets you reach an invisible wall. The camera moves to an overhead view to stop you from seeing any further, but strangely, you can still target enemies beyond the wall - you just can't attack them.
There's also a flashback segment where you're recalling what happened before the quarantine came into effect. If you try to leave the island, no military air strike happens, but the invisible wall still keeps you from leaving. Way to tax Suspension of Disbelief, guys!
Donkey Kong 64 is very guilty of this in its hub area, set in the ocean. Trying to swim past the limits of the world just end up with your monkey wading at the same spot over and over.
NiGHTS Into Dreams includes a variation of the Invisible Wall combined with an invisible cannon, ala Motocross Madness. The edge of a Dream World is marked by a change in the floor to a strange purple surface, and trying to go on it or over it results in Claris or Elliot being flung back a large distance.
Annoyingly, NiGHTS: Journey of Dreams plays this normally. Quite annoying, since in the original, at least you could temporarily stop the Egg Timer... Here, the Awakers can't be stopped, so if you come up against an Invisible Wall, you're pretty much screwed.
A few Team Fortress 2 fan-made maps feature these on staircases. One server has dubbed them "Stairways to Heaven" because they have to go somewhere.
Although maps generally make good use of the Insurmountable Waist High Fence, the Demoman and Soldier are able to send themselves flying all over the place, easily clearing most all of these. As a result, the invisible walls are called in. Can be particularly annoying not having an indication of which rooftops you can access and which are behind unseen barriers.
Also, in one map, there are some roadside barriers keeping you away from barren desert. All normal jumps don't go taller than them, but the scout's double jump does. Invisible wall right there.
They're everywhere in The Legend of Zelda: Ocarina of Time, though most of them involve using the levitation code on a Game Shark to get to places you couldn't normally go. You can however reach the one behind the windmill at Kakariko village using the cuckoo in the windmill. Sometimes you can hookshot or shoot your arrows at invisible walls without realizing it.
Its direct predecessor, The Legend of Zelda: The Wind Waker, however, averts this trope spectacularly: Despite resorting to your boat telling you "It's too dangerous to continue", and some short patches of instant-kill water should Link swim there alone, is notable for averting this completely: some TAS-ers discovered some physically doable glitches to override these barriers (although a simple moonjump cheat code is more than enough), and, should you continue out-bounds, Link will literally 'fall over the edge of the world', or rather the Great Sea, in a huge Bottomless Pit.
Played painfully straight with the ridiculously high barrier surrounding Hyrule Castle.
In the original Japanese release, sunken Hyrule had barriers that were made to prevent players from leaving the path to Ganon's Castle and exploring the incomplete fields beyond. However, they weren't high enough to prevent some clever players and their Deku Leaves, so in the International versions, the walls were made higher.
Left 4 Dead has them, but unless you're an Infected who got bored you likely won't run into them. The game lampshades it when you're close enough by putting up a "Wrong Way" sign.
It is quite possible to encounter invisible walls while playing as the survivors, but you would rarely find them. They are a bit more common in Left 4 Dead 2 and are in places such as over a fence or on top of a wrecked bus. This is to prevent players from exploiting the maps by being tossed in the air when knocked over by a Charger.
In American McGee's Alice, there are several invisible walls. But they also use giant slimy tentacles as walls. You can jump on just about anything, but you can't jump on those tentacles - you have to find a way around them.
James Cameron's Avatar The Game usually makes a reasonable use of solid walls and only occasionally abuses a Gentle Slope of Unclimbability, but once you start riding a banshee or flying a helicopter, the invisible walls become your ultimate menace as they appear in the middle of the most obvious route, enemies just beyond range of your gun safely shoot at you from the other side, and your vehicle takes damage as you crash into them.
In Black & White, land 1, before you build the temple or get your Creature, if you try going near the Aztec village or beyond the gates, you get blocked by an invisible wall. It lights up white if you crash into it, but if you don't it's invisible.
EverQuest had this as the way to keep players from passing beyond the borders of a zone at any place other than a designated zone transition. Most zones in the game were basically large square or rectangular maps with a wall-like hill around the edge with an invisible wall about halfway up it, and early on, when the game had no maps for navigation it was common for players to navigate by following the zone walls.
ATV Offroad Fury 2 has an extreme case of this. In Freestyle mode, if you go too far, you not only crash into an invisible wall, but also fly a bajillion times farther than you would upon hitting a normal obstacle.
These crashes were actually pretty fun to watch... some people didn't even bother trying anything but freeride because they wanted to see if they could ever kill the rider. (They couldn't.)
One of the most egregious examples was Vampire Rain for the X-Box 360. You're a stealth operative on the street trying to sneak around the city and avoid all detection, because most of the people in the city are vampires who will rip you in half the moment they see you. Most of the city is rendered at any given time but there are invisible walls all over the place to keep you focused on your next objective, and you likely won't even realize it until you try to cross a street to avoid a vampire and BZZT! "Mission Boundary!" So annoying.
In Fable II whenever you try to swim too far away from the land mass, the game gives you an Invisible Wall and says something along the lines of "There is no reason for you to go any farther." Still kills Willing Suspension of Disbelief a bit, but at least it's the truth...
The Force Unleashed had lazy invisible walls during the whole prologue Level. You try to go over a cliff or jump? Nonono, young Padawan! You are allowed to do this first in level 2... it probably has something to do with you being unable to die in this level, even when your lifebar is nonexistent but they could have just taken the level deeper into the forest, where there are no descents.
Super Mario Sunshine has one in the middle of the ocean which not only keeps you from going out too far, but also from sequence breaking by selecting a mission in one area and then swimming directly to another.
Quite gratuitously used in Painkiller, though for the most part they're in context.
Averted in Big Rigs: Over the Road Racing, one can climb over the slopes (no matter how steep) where the walls would be and continue to drive into the white void.
An Untitled Story has these on the edges of game world, in a genre where world borders are usually closed with walls. They also appear during several boss fights as well as in the form of invisible ceiling in CloudRun and MountSide.
The Fushia City Gym in Pokémon Red and Blue has a Gym puzzle of invisible walls. However (until the remakes, at least), there are slight pattern differences in the floor tiles that determine tiles which have invisible walls on them.
If one plays the original games on a Game Boy Color, Game Boy Advance, or Game Boy Advance SP, the invisible walls can be seen.
Serious Sam II has a lot of invisible walls to prevent the player from escaping the stage or falling off. Serious Sam I uses teleport triggers instead and jump pads for those who still manage to get out.
Most racing games have these when you get your car airbourne and attempt to jump over a wall or barrier of some sort.
Forza Motorsport 4 rather pointlessly has on on the Top Gear test track. If you go backwards over the hump on Gambon corner fast enough, you hit an Invisible Wall coming up from a wall that seems to be about a foot high.
Champions Online has an Invisible Wall around the edge of every zone. While they may not be explained, you at least get a warning that you're about to reach it - the screen suddenly goes black and white, and just a bit blurry.
FEAR 3 has many, many places you should be able to get though, boxes you should be able to jump on and surfaces you should be able to climb, only for you to bounce off mid air if you attempt to.
In Guild Wars 2, the game has a mixture of Invisible Walls mixed with natural barriers (A 100-foot high wall or the depths of the ocean for example), but sometimes the wall is seen in places that should be logically explorable, or the wall is extended a bit too far away from the steep mountain your character has come up against.
Invisible Walls can be found, surprisingly, in Microsoft Flight Simulator 2002. Flying too far north and possibly south results in the plane hitting an invisible wall, beyond which the terrain is very low-res. Interestingly, the plane does not actually "crash" into the wall; instead, physics turns off for the plane, leaving it hanging in the air, until the plane is no longer in contact with the wall.
While Ōkami mostly avoids them by having reasonable barriers, they become painfully obvious if you decide to explore the coastal areas a bit more after getting the Water Tablet. In certain spots there are even islands you can see but not get to because Ammy just won't advance past a certain point.
The arenas used for The Hunger Games are surrounded with forcefields that repel anything that runs into them. Of course, the Gamemakers have plenty of other ways to shepherd wayward Tributes back towards the middle.
Catching Fire also has one that traps Katniss and Finnick with the jabberjays sounding off the cries of their loved ones in pain. Crowning Moment of Heartwarming ensues when Katniss and Peeta stand on opposite sides of the wall, pressing their hands to the glass.
In the movie Cabin In The Woods, the entire campground is surrounded by one of these (except for a small tunnel), as some of the campers find when they try to escape. When run into, the wall becomes a Beehive Barrier.
Greg Egan uses this in a rare non-video game example in Permutation City. The simulated city introduced right at the beginning contains a 3D model of a single apartment and enough of the rest of the city to accurately reproduce what you can see out of the window. However, get out of the apartment and the many limitations of the simulation become apparent very quickly, including that a couple of blocks out an invisible wall prevents you from proceeding further. Egan even wrote this specifically as an "edge of the universe" where any attempt to move outward is simply cancelled, rather than mere wall with a surface.
Jon Tron considers these a mostly harmless Necessary Weasel, which is notable since he frequently nitpicks much smaller things for breaking a game's immersion or flow. He comments that a game can't go on forever and when you have to go out of your way past anything interesting to find them anyway, it's okay for the game to stop you before it crashes. He does have a problem with particularly blatant ones that look like somewhere you should be able to traverse, though.