The Rubik’s Cube is one of the world’s most famous puzzles. First invented in 1974 by Hungarian professor Ernő Rubik, it has challenged puzzle enthusiasts for over 40 years. The classic 3x3x3 cube consists of 26 cubelets that can be rotated and shifted to scramble and then solve the cube. While the 3x3x3 is the most common Rubik’s Cube, there are many different sizes and variations that have been created over the years. From 2x2x2 cubes to massive 17x17x17 cubes, these twists on the original test the skills and patience of even the most seasoned solvers. So which of these is objectively the hardest Rubik’s Cube to solve?

## Factors Determining Cube Difficulty

There are several factors that contribute to how difficult a Rubik’s Cube is to solve:

### Number of Cublets

The most straightforward factor is the number of individual cubelets that make up the full cube. A standard 3x3x3 Rubik’s Cube contains 26 cubelets. A 4x4x4 contains 56 cubelets, a 5x5x5 has 96, and so on. The more cubelets in play, the more complex manipulations are required to correctly position each one during the solving process.

### Number of Orientations

On a 3x3x3 cube, each cubelet has only one orientation meaning there is only one way it can be correctly positioned. Larger cubes introduce cubelets that can be rotated and oriented in different ways relative to the other pieces. This vastly increases the number of potential combinations and permutations.

### Parity Errors

Parity errors occur when cubelets are oriented correctly but the overall parity of the cube is wrong, meaning edge pieces are incorrectly swapped or flipped. Larger cubes allow for more opportunities for these tricky parity errors to occur during the scramble and solving phases.

### Complexity of Move Set

The rotation moves required to solve a cube also become more elaborate as the cubes increase in size. Instead of just basic R and L turns, larger cubes introduce additional types of rotations like 3Rw and 3Lw. The longer sequence of moves exponentially grows the solution space.

## Candidates for Most Difficult Rubik’s Cube

Based on those criteria, these Rubik’s Cubes stand out as some of the most difficult to solve:

### 5x5x5 Professor’s Cube

The first Rubik’s Cube to really increase the complexity was the 5x5x5 cube. The V-Cube 5 was the first commercially available 5x5x5 cube when it was released in 2008. With 96 cubelets and multiple cubelet orientations, it presents a dramatic increase in difficulty from the 3x3x3 cube. Parity errors are also very common during the solving process.

### 7x7x7 V-Cube 7

The V-Cube 7 boosted the size up to 343 cubelets with parity considerations. The proportionally longer move sequences required and increased opportunity for errors push this cube into the elite difficulty tier.

### 11x11x11 ShengShou Cube

The current largest mass-produced cube is the ShengShou 11x11x11 cube, containing 1,331 movable pieces. Oskar van Deventer’s Over The Top cube can be reconfigured to up to 17x17x17 but intricate mechanics are required to allow it to move at that size. The ShengShou 11x11x11 represents an enormous challenge with the most cubelets and longest move sequences of any readily available puzzle.

### Super Geranium/Over The Top Shapemods

Special mechanic Rubik’s Cubes called “shape mods” feature cubelets and mechanisms reconfigured into new patterns, shapes, and forms. Two incredibly difficult shape mods are the Super Geranium, which has many small intricate leaves and petals, and the Over The Top, which has both a cubic and spherical component. Their irregular designs mean that they cannot be solved using conventional Rubik’s Cube move sets.

## Records for Solving Hard Cubes

Here is a look at the current world records for solving some of these cubes:

Cube Type | Record Holder | Time |
---|---|---|

3x3x3 Cube | Yusheng Du (China) | 3.47 seconds |

5x5x5 Professor’s Cube | Max Park (USA) | 40.69 seconds |

7x7x7 V-Cube | Max Park (USA) | 1 minute 37.24 seconds |

11x11x11 ShengShou Cube | Ciarán Beahan (Ireland) | 8 minutes 59.40 seconds |

## Conclusion

Based on complexity, number of pieces, and the records for the fastest solving times, the Rubik’s Cube that objectively presents the greatest challenge to puzzle fans is the 11x11x11 ShengShou Cube. With over 1,300 cubelets to correctly orient during multiple step sequences that can include over 60 moves, it pushes the limits of human focus, memorization, and dexterity. Solving it requires mastery of various techniques that are required for smaller cubes, plus immense dedication of time and practice. For those who desire the ultimate test in Rubik’s Cube solving, the ShengShou 11x11x11 represents the hardest puzzle available. While new size records may be achieved, as of 2023 this mammoth cube is currently the most difficult Rubik’s Cube to solve.