The Mirror Cube: Same Colour, Different Sizes

Quick answer: the Mirror Cube is a shape modification of a 3x3x3 where every piece is the same colour but a different size. You align it by shape rather than by colour. Hidetoshi Takeji invented it in 2006 and called it the Bump Cube, after the uneven surface it develops when scrambled.

Best for: people who can already solve a Rubik's Cube and want the same solve to feel completely unfamiliar.

Take the colours away from a cube and you would expect it to get easier. Replace them with sizes and it does the opposite.

What Is a Mirror Cube?

Mechanically it is an ordinary 3x3x3. The core, the turning, the piece count and the permutations are all identical to the standard cube.

What changes is the cutting. Instead of twenty-six equal cubies, the pieces are cut to different heights, widths and depths. Solved, they assemble into a perfect cube. Scrambled, they stick out at every angle, which is exactly the bump the original name referred to.

Most are finished in a single reflective colour, usually gold or silver, which removes colour as information entirely and gives the puzzle its more common name.

How Do You Solve a Mirror Cube?

With the method you already have, reading a different signal.

The algorithms are unchanged. Any 3x3x3 method transfers directly. You are not learning a new puzzle, you are learning to see a familiar one differently.

Read height instead of colour. A corner belongs where its three dimensions match the gap. Centres are the key: each face's centre piece has a distinct thickness, and that thickness tells you which face you are looking at.

Identify the centres first. On a standard cube the centres tell you the colour scheme for free. Here you must work out which centre is which before anything else can be oriented, and that single step is most of the difficulty.

Work by feel as much as by eye. Experienced solvers often run a thumb along a face, because a mismatched piece is easier to feel than to see on a reflective surface.

Why Is It Harder Than a Normal Cube?

Because the information is harder to read, not because the puzzle is deeper.

Colour is a very efficient signal. You see a blue sticker and you know instantly where it belongs. Size is comparative: you cannot tell whether a piece is the tall one until you have something to compare it against, and on a scrambled cube the comparisons are all half-hidden.

The reflective finish makes it worse, which is a genuine design flaw dressed as a feature. A mirrored surface shows you the room, your own hand and the other faces of the cube, all competing with the edges you are trying to judge.

So the difficulty is perceptual. A solver who knows a method will get there; it just takes several times longer than the same scramble in colour.

Is the Mirror Cube Worth Owning?

If you can already solve a cube, it is one of the best value additions there is, because it reuses everything you know and still resists you.

If you cannot, it is the wrong starting point. Learning a method and learning to read shape at the same time is two problems at once, and the usual outcome is a scrambled gold lump in a drawer. Learn on a colour cube first.

It is also, unavoidably, the best-looking puzzle on most shelves, which is a real part of why people buy it.

Does It Have the Same Number of Positions?

Exactly the same, and this is the cleanest way to see what the Mirror Cube actually changes.

Because the mechanism is an unmodified 3x3x3, the state space is identical: the same 43 quintillion positions, the same group structure, the same God's number of twenty. Not one position is added or removed by recutting the pieces.

So the Mirror Cube is not a harder puzzle in any mathematical sense. It is the same puzzle with the labels removed and replaced by a signal humans read far less efficiently. The difficulty is entirely in the interface, which is a genuinely unusual thing for a puzzle to do on purpose.

That also explains why solve times drop sharply with practice in a way they do not on a deeper puzzle. You are training perception, not learning method, and perception improves fast.

What Should You Look For in One?

Mirror cubes vary more in quality than almost any other twisty puzzle, and the reason is the stickers.

Check whether the faces are stickered or laminated. Cheap mirror cubes use adhesive foil on each face. Because the pieces are different sizes, those stickers are different sizes too, and the small ones peel first. Once a few have lifted, the puzzle is finished, because the surface is the information.

Prefer a matte or brushed finish to a high-mirror one. This sounds like a downgrade and is not. The more reflective the surface, the more the room, your hands and the cube's own faces compete with the piece edges you are trying to judge. A brushed gold cube is noticeably easier to read than a chrome one and no less attractive.

Turning quality matters more here, not less. On a colour cube you can see a misalignment. On this one a slightly off layer looks much like a correctly placed tall piece, so a cube that corner-cuts well saves you from mistakes you would not otherwise notice.

What Do We Make That Is Like This?

No twisty puzzles at all. What we do make is a different answer to the same question the Mirror Cube asks: can a puzzle be hard because of shape rather than markings?

That is the whole premise of turning interlocking cubes, where pieces are plain and the difficulty is entirely geometric. EcstaTIC is the cleanest example, two pieces and one rotation, and Identical Twins makes the point harder still with two identical pieces.

If the appeal was the shape-shifting itself, the Gear Cube is the twisty puzzle we write about that is most approachable. The shelf here is cube puzzles and the range is mechanical puzzles.

The other way to alter a 3x3 without touching how it turns is to take its middle out entirely: the Void Cube.

Frequently Asked Questions

What is a Mirror Cube?

A shape modification of a 3x3x3 Rubik's Cube in which every piece is the same colour but a different size. It is solved by aligning shapes rather than colours, and forms a perfect cube only when solved.

Who invented the Mirror Cube?

Hidetoshi Takeji, in 2006. He called it the Bump Cube, after the uneven surface it develops when scrambled. It is also sold as Mirror Blocks.

Can you use Rubik's Cube algorithms on a Mirror Cube?

Yes, directly. The mechanism is an ordinary 3x3x3, so any method transfers unchanged. The only difference is that you track piece size instead of colour.

Is a Mirror Cube harder than a 3x3?

Harder to read, but not mathematically deeper: it is mechanically an ordinary 3x3 with exactly the same positions. Colour is an instant signal; size is comparative, so you cannot identify a piece until you have something to judge it against. The reflective finish adds glare that competes with the edges you are trying to see.

Should a beginner start with a Mirror Cube?

No. Learning a solving method and learning to read shape at once is two problems at the same time. Learn on a standard colour cube, then the Mirror Cube reuses everything you know.