[[quoteright:317:[[VideoGame/RobinHoodPrinceOfThieves http://static.tvtropes.org/pmwiki/pub/images/perplex2b_8754.JPG]]]]
[[caption-width-right:317:The tower is blocking him.]]

->''There's even enemies that you can barely see, like this tiny mouse on the fence in the background.'' (The tiny mouse somehow hits Dorothy) ''Like are you kidding me? That doesn't even make sense from a perspective view-point. She's like standing in front of the fence.''
-->-- ''WebVideo/TheAngryVideoGameNerd'' on ''The Wizard of Oz'' for SNES

Before the days of 3D graphics, gamers were only concerned with three layers: the background, the foreground, and the "main layer" in between that the player actually resided on. This is the only layer that is supposed to matter. Sometimes the foreground might [[ObstructiveForeground block your view]], and [[BackgroundBoss some]] [[InvincibleMinorMinion guys]] may attack from the background, but that's it.

When this trope is in effect, you can throw all the rules of background vs. foreground out the window. Those GoddamnBats clearly flying in front of bricks that block you will still kill you with CollisionDamage if you get near them. See that thunderstorm in the distant background? It'll kill you if you're in front of it when lightning strikes. If you're lucky, you can shoot through walls too.

The most common instance of this is enemies and bullets (''[[TheComputerIsACheatingBastard their]]'' bullets) that go through walls by overlapping them. Most gamers just take this for granted, as it has been happening since ''SuperMarioBros'' with Bullet Bills, if not earlier than that.

This is like DepthDeception except with any semblance of logic removed. The enemy or object in question isn't actually especially big or small... it just somehow affects you despite the fact that it logically shouldn't be anywhere near you. It's most common in [[IsometricProjection Isometric]] and [[SideView Side Views]], and optical illusions such as the [[http://en.wikipedia.org/wiki/Penrose_stairs Penrose staircase]] make it OlderThanTheNES.
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!!Examples:

* As quoted, ''TheWizardOfOz'' for the SNES features some incredible examples. Aside from the mouse, there are grandfather clocks you can go in front of... but the hands on them [[CollisionDamage hurt you]].
* ''VideoGame/MegaMan'' is an early example of a game where your bullets go through walls.
** The series and its spin-offs sometimes flip-flop about it. In ''VideoGame/MegaMan and Bass'', Bass can't shoot past walls with his buster unless you equip a certain item. ''VideoGame/MegaManX 5'' and ''X6'' made most basic projectiles unable to pass walls, yet in ''X5'' X's charged shot with the Falcon Armor can pierce both enemies and solid walls. One game later, the armor gets broken and Alia barely fixes it, so among other things the charged shot looks exactly the same but can't penetrate anything.
* In ''[[VideoGame/CastlevaniaChroniclesOfSorrow Castlevania: Dawn of Sorrow]]'', the Final Boss (Menace) can hit you (for a lot of damage) with a foot that is clearly in the background behind Soma. It even is of a darker shade to emphasize that is indeed in the background. Even worse, there are very many enemies in the game (various forms of Barbariccia, the Valkyries, Demons, the various Mini-Demons, and Gaibon come to mind, most of whom fly, whose attacks and AI can lead them off-screen, where they can easily prepare or launch attacks that you can't even see. Of course they are out of range of most of your weapons and Bullet Souls. Gaibon, for example, breaths fire diagonally downward, and you fight them in tall shafts. Sometimes as many as three at a time. All hiding off-screen, torching you when you try to climb up to them.
* ''VideoGame/TransformersConvoyNoNazo'' has solid blocks that the player can't shoot or pass through. Enemies fly in front of the bricks, but they still kill you with CollisionDamage if they touch you.
* In ''SuperMarioBros.'' there was a cheat code for the Game Genie, STAGEO. It was a true GameBreaker, as it turned every enemy into the DemonicSpiders-esque Hammer Brothers. The Hammer Brothers could noclip through blocks, but it was never actually seen in the vanilla game. The hammers they throw are also able to noclip.
* ''VideoGame/SuperMarioBros3'' where you could hide behind the background of certain levels. This is wholly intentional, however.
* [[{{Shmup}} Space shooters]] in general are likely to allow enemies and their bullets to fly in front of walls in your way, and yet they still affect your layer. Sometimes walls are electric or made of HardLight that enemies can pass through to avert this. Additionally, since the player's ship's hitbox is usually very small, bullets will appear to pass over it without colliding... unless the bullet hits the very center of the ship.
** {{Danmaku}} shooters are the worst, as not only will bullets fly in front of obstacles if present, but also ''in front of your character'', unless they collide with a hitbox. The only way this would work is if the hitbox is actually closer to the player than the rest of the character -- which makes sense if it's a cockpit in a vertically-scrolling shooter, but significantly less so if it's part of a person or a cockpit in a side-scrolling shooter.
** In a surprising version of this, in {{Ikaruga}}, not only do enemy bullets ''not'' do this, but in the second stage, the ''player's'' ship can act as part of the background to avoid certain obstacles. This is because if the ship is lined up perfectly with the one-pixel gap between obstacles, the ship itself will appear to fly under them unharmed.
* ''VideoGame/IWannaBeTheGuy'' has both DepthDeception and this.
* In ''VideoGame/StarCraft'', it's possible to shoot between high ground and low ground even if the ground should be in the way. It's also possible to shoot from low ground to low ground when there's a wall in the way.
** ''VideoGame/WarcraftII'' had submarines which could only hit other ships; they could hit over land. This is a limitation of the pathing code of both games, although it's made up by the fact that a unit that shoots another makes itself visible(and thus shootable) even if you wouldn't see it normally.
* ''WaynesWorld'' for the SNES has a level with poles that are clearly in the foreground, but still block players walking on the sidewalk.
* ''Equinox'' is an early 2D game that simulates a 3D isometric environment. There is a minor DepthPerplexion glitch that can occur in the game due to the graphic layering that performs the simulation. [[http://www.flyingomelette.com/equinox/glitch.html Read here for a good explanation.]]
* ''IndianaJonesAndTheTempleOfDoom'' for the NES is just... wow. It's simultaneously an isometric 3D view and overhead view.
* ''VideoGame/LaMulana'''s most common enemy is a bat (in two sub-types) that flies "in front of" the walls. And it's definitely of the [[GoddamnedBats Goddamned]] kind.
** And because they are of the same color, they seem to fly BEHIND water and other objects that are behind your character.
* The ''VideoGame/{{Glider}}'' games had balloons, copters and darts that could fly in front of furniture ([[DeadlyWalls deadly to crash into]]) but caused CollisionDamage all the same. The games never had a strong sense of layering (it mostly affected graphics); it's remarkable that the thunderstorms in ''Glider 4.0'' '''don't''' kill you.
* ''VideoGame/LittleRedHood'' is supposedly in a 3/4 overhead view, but if you jump in front of a tree, your head bumps into the trunk. Another AVGN explanation is at the 11 minute mark [[http://www.gametrailers.com/video/angry-video-screwattack/59650 here]].
* The NES game ''VideoGame/RobinHoodPrinceOfThieves'' was insane with this, as shown in the picture at the top: Much like the ''Little Red Hood'' example above, the game played out in an isometric perspective, which factored into the collision detection, forcing players to swerve around towers so as not to walk straight into their peaks ''on ground level''.
** Also seen in ''[[{{Contra}} Super C]]''.
* Pretty much the same problem was present in the overworld of ''Mickey's Racing Adventure'' for the Game Boy. The Treehouse Glade in particular is made rather maze-like by your inexplicable inability to walk behind trees.
* In the first ''SonicTheHedgehog'', Batbrains can fly through walls in the Marble Zone.
** Against the FinalBoss in the [[{{Sonic2}} second game]], both of the giant robot's claws can hurt you if either of them are sticking out beyond the torso - both the one logically in front of Sonic and the one logically behind him - even if they're sticking out only a little bit and not enough for the arms to be angled towards the middle, leaving the player with some tricky timings to make if they don't want to wait for the other moves.
* Freeware game [[http://teknopants.com/games/actionfist/ Action Fist]] has this issue in the game's second zone, a [[UnexpectedGameplayChange driving level]]. Jumping and moving up the screen have nearly the exact same result, except the former makes you come back down. Only averted with the boss, whose lightning attack can be jumped over.
* ''VideoGame/TheLegendOfZeldaCDIGames'' had numerous problems with that. For an example, a top part of one of the pillars blocks the player but the bottom part doesn't. Many screens use painted landscapes that have a lot of depth, but the gameplay is strictly 2D as shown [[http://youtu.be/xLxqfmpjB-U?t=6m37s here]].
** While we're on the subject, this trope also affects at least one main series game: ''VideoGame/TheLegendOfZeldaLinksAwakening''. The game uses isometric perspective but lacks Z-levels, so it's possible to, say, hit an enemy on the ground while swinging the sword at the crest of a jump because Link and the enemy are at the same height on the screen, even though perspective implies that the enemy is below and to the side of Link. This was fixed in ''VideoGame/TheLegendOfZeldaOracleGames'', which use the same engine.
* In ''Trilby: VideoGame/TheArtOfTheft'', guards tend to pass right under your sprite. The catch is you're hugging the wall farthest from the screen, meaning they should be layered on top.
* In the ''NintendoWars'' franchise, planes can fly over any space, but can't pass through spaces occupied by other units. Even ground units. Even naval units. [[UpToEleven Even submerged submarines.]]
** The same happens in ''VideoGame/SuperRobotWars'' games.
* The first ''VideoGame/WizardsAndWarriors'' game had floating tree stumps in the forest level.
* The otherwise excellent ''VideoGame/GoldenSun'' suffers from this, in that sometimes, due to the overhead view, it's difficult to tell if a pillar is standing upright or lying down. It can also be tricky to gauge distance between platforms, resulting in several minutes of random wanderings until you accidentally stumble across the solution. Thankfully, it only happens occasionally.
* The "shoot through walls" variety is [[JustifiedTrope Justified]] in the ''{{Metroid}}'' series, where Samus can only shoot through walls if she has the Wave Beam, which explicitly has the ability to penetrate solid matter.
* ''{{Rygar}}'' had this issue in the overhead areas. If you jump, your Diskarmor would register a hit on whatever was in the same place on the screen, even though your hero's shadow was about six tiles below. Savvy players could use this trick to easily defeat one of the bosses.
* ''SuperMarioBros2'' has Pokeys that go right through cacti, even though the cacti block you. And you can stand on top of the Pokeys, as well, "riding" them past the normal cacti. [[note]][[LetsPlay/ProtonJon MOVE FASTER POKEY!]][[/note]]
* In ''VideoGame/{{Terraria}}'', Fire Imps can throw fireballs in front of blocks, but most of your projectiles get blocked by them.
* This is [[http://kotaku.com/5820692/there-are-unexpected-problems-bringing-old-games-to-the-3ds apparently]] an issue with making 3DS versions of older games. Each sprite has their depth coded into the 3D version, which works great, until, uh-oh, enemy X existed on two planes at once in the original game. Another issue is bullets in an overhead perspective that make their way from a ground shooter to the player in the air; on a flat screen, the player just assumes the bullet was increasing in height as it reached the player, but of course, that was never programmed in; the bullet hits the player as long as the two overlap, with no regard to height.
* In the original ''VideoGame/PokemonRedAndBlue'' games, the player character could only move over objects or be blocked by them; thus, you could not, say, walk behind a skyscraper, even a road could pass behind it, because it's blocked by [[ThreeQuartersView your game perspective]]. This was changed in ''VideoGame/PokemonRubyAndSapphire'' where you could walk behind lampposts.
** This trope was still in effect in ''VideoGame/PokemonRubyAndSapphire'', and it was actually more baffling than before. Whereas in previous games, you knew that you could never walk behind a building as even its roof would block your way, Gen III was far more inconsistent with this. For instance, you could walk behind a building, but its collision data treated it as if it was wider than its graphics depicted it as, so its the highest parts of its walls would block your path even though it was evident that you weren't touching them. For example, by looking at a Pokémon Center's roof one would assume that the building is only one or two tiles long from south to north, whereas the collision data seems to think it's actually three tiles long (meaning that 3/4 of it was solid). And then there was the Cycling Road, a bridge that had areas that allowed the player to walk under it, as well as areas that blocked him or her despite having nothing under them.
*** Gets even more {{egregious}} in VideoGame/PokemonDiamondAndPearl and later, where this is still in play, ''even though the game is now rendered in 3D''. That's right, now you can see what's behind those buildings thanks to perspective, but ''you still can't actually go there,'' even if it looks like you could. For example, there are several places where you can clearly see one tile of space between the north face of one building and the south face of another, but the game will not allow you to walk onto that space.
* In the C64 version of ''{{Rambo}}'', the ''tops'' of palm trees would block your path and had to be blown to smithereens with explosive weapons if you were to pass. All the while non-explosive projectiles from your and your enemies' weapons freely travel through everything.
* This trope is the WHOLE POINT of ''VideoGame/{{Echochrome}}'', where your player character (a little wooden artist's mannequin) can travel across a gap if you couldn't see it.
* You can't walk behind flowers in pot in a table in ''VideoGame/FinalFantasyIV''.
* Some of the beams in the New York level of ''SamuraiZombieNation'' come from the buildings in the background, but they damage you just the same as the ones in the foreground.
* In the online ''Literature/WarriorCats'' Hunting Game, enemies can travel through tree stumps that you can't get past without jumping over them.
* ''VideoGame/TheSimpsonsBartVsTheSpaceMutants'' for the NES is basically a ''SideView'' 2D game with graphics made to look like you're in a 3D enviroment.[[note]]Although the skateboard part of the first level allows you to move up and down and not get damaged by enemies in the background, but this is probably through some clever use of smaller collision boxes (the enemies aren't high enough to reach your face or torso) and the skateboard working pretty much like a jetpack.[[/note]] This sometimes allows you to [[PerspectiveMagic stand on the horizon or cross a river by jumping to the background where it's more narrow (but you're still at the same size).]]
* Since enemies in ''VideoGame/LiveALive'' take up multiple squares on the battlefield, there are plenty of times when you're blocked by them when it looks like you could just travel behind or below them.
* In the first level of the ShiftingSandLand state of ''TheAdventureOfLittleRalph'', there is a bleached skull that is in the background. Later in the level, there are bleached ribs, also seemingly in the background. Since the first bone seen was a background element, the ribs must be, too. NOT! The ribs are actually SpikesOfDoom that ''impale'' Ralph. This may give players an unwelcome and bloody surprise.
* VERY evident in ''VideoGame/GatlingGears''. Almost all projectiles exist on one plane, as such, bullets and enemy rockets will "pass over" walls, structures and terrain, no matter what elevation. You can take advantage of this, however.
* Obvious in ''VideoGame/DeadlyTowers''. The game uses an isometric perspective, but hitboxes surround entire sprites. Many sprites are much taller than they are wide, resulting in hits registered (on both enemies and the player character) even when, logically, no contact should have been made.
* The Digipen Game ''[[https://www.digipen.edu/?id=1170&proj=25930 Perspective]]'' is ''all about this''. You can switch from controlling the camera to controlling a character from a 2D platformer, and you can walk from one wall to another in 2D mode.
* Many, many SuperMarioWorld hacks come under this if they use graphics not meant for 2D platformers (like isometric ones or three quarters view ones from games like SeikenDensetsu3). Good luck figuring out where the floor is solid and where it isn't in levels like Dark Castle or Dragon's cave in BrutalMario for instance. Or which bosses are foreground and which are background in the same game.
* In ''Mystery Quest'' for the NintendoEntertainmentSystem, the bats can and will fly through the ground and other solid objects.
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