Algorithm notation. The Ghost Cube is read on its mechanism layers rather than on its sculpted surface. U E D are the three horizontal layers and turn by any multiple of the ghost's offset, so U45, E30 and D90 give the angle in degrees while a plain U is 90. R L F B M S and the wide moves Rw or r turn only while every horizontal layer sits on the lattice; A aligns them all first. An apostrophe inverts a move, 2 doubles it, x y z rotate the whole puzzle, and brackets repeat or invert a group: (R U R' U')x3 or (R U R' U')3 plays the trigger three times and (R U)' plays its inverse. On the 4x4x4 ghost a lowercase r, u or f is an inner slice. The second input loads an algorithm into the player under the cube, played on the cube as it stands (set up a scramble with the first input): step through it with the buttons, press play, or click a move to jump there.

Ghost Cube simulator: solved on the left, scrambled on the right

Online Ghost Cube Simulator

Free Ghost Cube simulator in 2x2, 3x3 and 4x4. Align the twisted layers, scramble and solve the shape-shifting ghost in gold, silver or colour, with a timer.

Ghost Cube simulator: align, turn, solve the shape

The Ghost Cube was invented by puzzle designer Adam G. Cowan in 2008, inspired by Tony Fisher's Golden Cube, and was later mass-produced by Meffert's. Cowan's goal was a 3x3 shape modification that is as challenging as possible while allowing only one solution. Inside it is a standard 3x3 mechanism, but the cuts are skewed against the outer cube and every piece is an irregular chunk. The solved state is a cube shape, and with a single-colour finish there are no colours to help you.

Solved silver Ghost Cube by Meffert's with irregular black cut lines across its faces
When solved, the Ghost Cube is a plain cube cut at odd angles.

Why some faces will not turn

The defining feature of the Ghost Cube is that its horizontal layers sit twisted off the grid when the puzzle is solved. In this simulator's 3x3x3 the top layer starts 45 degrees off and the middle layer 30 degrees off. Until they are lined up, the vertical faces are locked, just like on the real puzzle, where some moves are blocked until you make a setup move. You have three ways to line them up:

  • Drag a horizontal layer: it snaps onto the grid when you get close.
  • Press the Align button or the A key to line up every layer at once.
  • Type partial turns such as U45 or E30 in the algorithm input, where the number is the angle in degrees.

The badge over the puzzle tells you which layers are still twisted. To finish a solve you have to park the layers back on their odd angles, so the last move is often a partial turn that closes the cube.

Sizes and finishes

Pick a 2x2x2, 3x3x3 or 4x4x4 mechanism inside the same cube-shaped shell. Golden and Silver are the classic shape-only puzzle. Colored gives each face of the shell a real colour, which makes it much easier to see where pieces belong and is a good way to learn. Chaotic bakes the colours onto a scrambled shape, so solving the colours gives you a bumpy shape and the cube is a second puzzle.

Five Ghost Cubes in a row, growing from a 2x2x2 to a 7x7x7 mechanism
The Ghost Cube idea has been applied to cubes of several sizes.

How to approach a solve

According to the Ruwix Ghost Cube page, the puzzle can be solved much like the layer-by-layer beginner's method. Two things make it harder. First, the centres are not square, so their orientation matters and you may need centre-twisting algorithms. Second, there is a parity case to watch for. Use the centres as your reference, build one layer at a time, and check after each step that the pieces fit together as a smooth surface.

Scrambled silver Ghost Cube with jagged, irregular pieces sticking out in every direction
Scrambled, the pieces give few clues, so solve by fitting shapes together.

Practice tools

Drag layers to turn and drag the background to orbit; the keys u e d r l f b m s turn layers in standard cube notation, with Shift for the inverse. Scramble plays an animated random mix, Undo takes back a move and Reset returns to the solved ghost. The timer runs only when you press Start or Space. The algorithm player under the puzzle steps through a sequence move by move, and the demos, such as "Six sexy moves, parked back to the start", show the align-turn-park rhythm. The link and embed boxes share your scramble or put the puzzle on another site.

Is the Ghost Cube harder than the Mirror Cube?

Both are one-colour 3x3 shape mods, but the Mirror Cube keeps all its cuts parallel to the faces, so every turn is always allowed and the pieces are simple blocks. The Ghost Cube's skewed cuts, locked faces and non-square centres make it considerably harder to read.