Optical / Spatial / Dimensional Trickery in Games

I’m currently considering a game design that makes use of various optical and logical tricks to fool the player as to how objects in the game are spatially-related – and thought I’d start by doing a bit of a review of what games are already out there that use similar techniques:


Sphinx Adventure

Released in 1982, this is one of the first computer games I can ever remember playing. Since the game was entirely text-based, there were no graphical tricks to deceive the player. However, that didn’t mean that you couldn’t be deceived and disoriented in other ways. The “trick” employed in this case was not a graphical one, but a logical one about the spatial connection between locations in the game.

This was back in the days before GameFAQs or games magazines, so players had to hand-draw maps of the game locations in order to find their way around. And, with only a sentence or two description for each room, it took a long time to figure out that rooms were sometimes connected to each other in impossible ways, creating infinite loops as demonstrated by the “iron passages” in this map extract…



The Legend of Zelda

The Lost Woods are a recurring theme that have appeared in numerous titles in the Legend of Zelda series. Here’s a screenshot of the original NES incarnation:


It’s a “room” with several exits. Successful traversal through the woods required you to know the correct pattern of exits to follow through the rooms. Taking a correct choice led you gradually through the rooms of the forest. But taking an incorrect choice led you immediately back to the start room. However, since each room looked identical, there were no visual cues to suggest this was what was happening, and players were often left disorientated by the fact that simple logical truths proved incorrect (i.e. starting from a room, going North once and then South once did not put you back where you started).



Echochrome was released on the Playstation over 6 years ago, although it feels more like a technical demo than a full released game. The technology which it demonstrates is the “Object locative environment coordinate system”, in which the relationship between objects in the virtual environment are not only determined by their 3d coordinates, but on the position from which they are viewed. Essentially if, from a certain point-of-view, two objects are made to look like they touch, then they do.

The levels were sparse and clearly M.C.Escher-inspired, meaning the entire focus of the game was concentrated on the gameplay mechanic of rotating the camera to create, and destroy, links between apparently separate platforms.


The exact same gameplay mechanic appear to have recently been re-used (in slightly more colourful form) in the game “Miika”:

image image
echochrome Miika


Monument Valley

Monument valley also appeared to take some inspiration from Echochrome, but developed the ideas further to include not only movement of the camera, but movement and rotation of parts of the level to create surfaces on which the player could walk (they also added a lovely art-style, making this feel much more of a developed game than Echochrome was). It still makes heavy use of the basic gameplay mechanic of making things appear connected in order to make them actually connected.



Mystic Mine

Mystic Mine takes just one specific element of MC Escher’s iconic isometric style and turns it into a fun puzzle game. The mine cart will only ever go “down” slopes but, due to the optical illusion employed, it is always possible to reach every part of every level. It’s a neat, compact game, and you can even get the source code on GitHub.




Most people are intuitively familiar with the concepts of a “2D game” and a “3D game”. “Perspective” challenges the boundaries between these genres by allowing the player to move around a 3D world in order to create a 2D world based on the view of world objects from the current camera position. Unlike echochrome, Monument Valley, Super Paper Mario etc., interaction is not dimensionally-restricted  – you can translate and rotate the camera in all three axes of the “3d” world to create an infinite variety of corresponding “2d” interpretations. It’s hard to describe and it’s surprisingly disorientating to play, but technically it’s very impressive to consider the level design process that must have gone into this:



Super Paper Mario

Super Paper Mario is hard to categorise as either a 2D game or a 3D game – rather, it offers the player the opportunity to switch between two different, but consistent, 2D perspectives of a 3D world. Like either looking at a cube from exactly front-on, or exactly side-on. The “paper”-thin theme allowed level elements and characters to have a physical presence in only two dimensions, meaning that obstacles in one view could easily be navigated by switching to the other view.



Fez creator Phil Fish says that Super Paper Mario is a terrible game, and that Fez is nothing like it. However, it’s hard not to see the similarity – with Fez similarly offering players different 2D perspectives of a 3D world:



I have to confess of never having heard of the game until I started writing this post, but apparently “Crush” on the PSP also uses a similar mechanic to Fez and Super Paper Mario – “crushing” 3D space into two dimensions:

File:Crush 3d.jpg File:Crush 2d.jpg


Tale of Scale

Tale of Scale” was created for the Ludum Dare 25 gamejam. Despite not really fitting the theme of “You are the Villain”, it featured a novel gameplay mechanic (and particularly impressive considering the 48hrs in which the game was developed) based around the apparent scale of in-game objects and forced perspective.

It’s somewhat reminiscent of the fantastic Father Ted episode in which Ted tries to teach Father Dougal about perspective:

Ted: [holding up a toy cow] All right, one more time. These… are small. The ones out there… are far away. Small. Far away

Dougal: [shakes his head in bewilderment]

The trick is that Tale of Scale dynamically adjusts the scale of objects such that objects that are small because they are “far away” can become actually small, and therefore can be picked up between the fingers.



It’s a technique familiar to anyone who’s ever taken holiday snaps of “pushing the Tower of Pisa back straight”, or “squeezing someone’s head between their fingers”, but to my knowledge it’s the first time it’s been used in a game as a puzzle mechanic.

The required code is actually surprisingly simple – here’s an implementation in Unityscript that will keep an object the same apparent size, whatever it’s true distance from the camera:


#pragma strict
private var startScale : Vector3;
private var startDist : float;
private var lastDist : float;

function Start() {
  startScale = transform.localScale;
  startDist = transform.position.z - Camera.main.transform.position.z;
  lastDist = startDist;

function Update() {
  var dist = transform.position.z - Camera.main.transform.position.z;
  if (dist != lastDist) {
    transform.localScale = startScale / startDist * dist;
    lastDist = dist;


Museum of Simulation Technology

MoST uses very similar game mechanics based around forced perspective as introduced in Tale of Scale, and also includes familiar world landmarks as objects in the game to accentuate the player’s preconception of what should be large or small.


BluePrint 3D

Not really a “trick” here, but I thought I’d include it anyway. An object has been smashed into pieces which, when viewed from a certain angle, will reconstruct the appearance of the original object. Rotate the camera to find the correct viewpoint and the object will be revealed. It’s a simple mechanic but nicely implemented:


The same mechanic is also used in “Starlight”, and, IIRC, some elements of “The Room” series.



IIRC, there’s also a game where, when the completed object is seen to be constructed correctly, it becomes real in the 3D world, but I can’t remember what the game is right now.

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