PENROSE

The guide

How the impossibility holds.

A Penrose triangle is three right angles that cannot close in ordinary space. They close from exactly one place. The first game asks you to find that place, twelve times. The second asks you to walk the triangle after it has become a building.

Fig. 01 · The diagram

Twelve plates, then six chambers.

The ring is The Fourth Corner. Three right angles that cannot all be true, except from one place. The monument is The Fourth Fold, and the figure moving through it has no fixed down. This is a drawing of the two games, not a picture taken inside them.

Open the plate
A diagram titled Penrose: Two Games, One Impossibility. A ring of twelve plates and a Penrose triangle stand for The Fourth Corner. An impossible monument and a falling traveller stand for The Fourth Fold.
01

Stand where it is true

A plate is solved only when every glowing loose end meets another, from where you are standing. Step aside and it comes apart. That is the whole of the first game.

02

Turn what you cannot see

From the fifth plate, a dial rotates a piece through a fourth direction. Colour marks depth in that direction. When you are right, the spare beam is simply no longer visible. Nothing was removed.

03

Walk with no fixed down

In the monument, the floor is whichever surface is under your feet. Three lights, a seam, and the echoes you leave behind carry you through six chambers and back to the door.

Game I · Twelve plates

The Fourth Corner

You do not walk through these plates. You walk around them. Drag the view, or use the arrow keys. Hold Shift for a finer turn. A plate ends when the loose ends coincide from that one vantage.

The first four plates are ordinary space. From Tribar onward the triangle is already arguing with itself. From The Fourth Corner, the missing beam points along a direction the picture cannot show until you turn it. Q and E, A and D, and Z and C turn the dials. Hints are H. The plate list is P. R returns the view to where the plate began.

Book one · three dimensions

  1. I
    TribarThree right angles, one triangle.
  2. II
    The FrameFour sides that never share a plane.
  3. III
    Tall OrderSame trick, steeper angle.
  4. IV
    Low SunThe extra beam was hiding behind the truth.

Book two · one dial

  1. V
    The Fourth CornerIt was there all along, end-on.
  2. VI
    Shadow PlayA shadow is a true thing seen from the wrong place.
  3. VII
    AscendingUp, and up, and home.
  4. VIII
    Vanishing PointNothing was removed. You just stopped being able to see it.

Book three · a dial for each piece

  1. IX
    Double TurnTwo turns you cannot picture, one triangle you can.
  2. X
    The Frame, FoldedFour ways to unfold it. One of them was a frame.
  3. XI
    The Long Way UpEvery step was level. You still arrived above yourself.
  4. XII
    WaterfallThe water never climbs. It still falls.
Begin

Fig. 02 · The monument

One triangle, built twice.

On the left, the twelve plates close into a triangle you can only hold from one place. On the right, that triangle has become rooms. Stairs run where a floor should be, and the traveller can stand on the wall.

Open the plate
An isometric drawing of both games. The Fourth Corner is a triangle of twelve plates. The Fourth Fold is a monument of stairs and arches, with figures standing on the floors and the walls.

Game II · Six chambers

The Fourth Fold

The triangle you closed is now a monument. You are a traveller in it. Click a stone path or a light to walk. Q and E turn your perspective, or drag the scene. The three lights are Aster, Vela and Lyra. Collect them, cross the seam, and return to the circular doorway.

Later chambers stop being a path and become a disagreement about which world you are in. W moves you between Matter, Echo and Beyond. R, on a memory plate, leaves an echo of you to hold a gate. Gravity follows the surface under your feet, including the ones overhead.

  1. I

    The Impossible Ascent

    The quiet sea

    Walk the triangle. Collect its three lights, then cross the seam to close the impossible circuit.

  2. II

    The Folded Garden

    The amber wastes

    The same architecture exists in three dimensions of possibility. Shift W to reveal its missing stairways.

  3. III

    A Memory of You

    The glass archive

    Stand on the marked plate. Leave an echo to hold the distant gate while you walk away.

  4. IV

    The Inverted Cathedral

    The violet hour

    One light waits beneath the cathedral. Gravity follows the surface beneath your feet.

  5. V

    Two Suns, One Shadow

    The verdigris sanctum

    Two pressure plates. Two echoes. Hold both, then carry the three lights through the sealed passage.

  6. VI

    The Fourth Fold

    The edge of the possible

    Perspective, memory and gravity converge. Restore the lights, leave your echoes, and close the final circuit.

WalkClick a path or a light
PerspectiveQ / E, or drag
DimensionW · Matter, Echo, Beyond
EchoR, on a memory plate
HintH, then H again
PauseP or Escape
GalleryC
Stop walkingSpace
Enter the impossible