# 4x4x4 Rubik’s Cube – Rubik’s Revenge

**The Rubik’s Revenge is the 4x4x4 version of the Rubik’s Cube. This is also a Hungarian invention, designed by Sebestény Péter. The interesting about this twisty puzzle is that can be used as a 2x2x2 if we don’t rotate the outer layers and like a 3x3x3 if we rotate only the outer layers. There are about 7.4×10 ^{45} possible permutations for this puzzle, which is quite a huge number.**

It has 24 edges, 24 centres and 8 corner fields. From the inside it’s is similar to a Rubik’s Cube but in this case the 4 centre pieces are held together. To take it apart pop out a centre piece with a screwdriver. I don’t recommend taking apart the whole cube because reassembling can be hard unless you have four spare hands.

## Variations

Maybe the most common 4x4x4 mod is the Octahedron, but there is a pillowed version, the Mirror 4x4x4 and 4x4x5 cube based on a similar mechanism. In some cases they fuse together some pieces changing the solution method. The 4x4x4 Circle Magic has a circle in the centre making it more tricky. An easier version is the Super Mask Magic where you don’t have to orient the edge pieces and the centres are all the same.

## The solution

The solution is a little bit more complicated than the classic Magic Cube’s method, but if you know how to solve a 3x3x3 then you will learn fast how to fix the Rubik’s Revenge. I assume that at this point you are familiar with the notation of the Rubik’s Cube. We are going to mark the double layer turns with lower case letters. The 4x4x4 cube is an even order puzzle and it doesn’t have a fixed centre piece which determines the colour of a face. If you’re not familiar with the colour scheme of the cube first you have to find which colour goes where by checking the corner pieces. According to this you have to make the 2×2 centres and after that pair the corresponding edge pieces. When this is done correctly the puzzle can be solved like a 3x3x3 Rubik’s Cube. For the sake of this tutorial let’s mark the pieces of a field with numbers from 1 to 16.

#### 1. Solve the centres

Let’s begin the solution with the white 2×2 centre (marked with 6-7-10-11). This can’t be such a big challenge. After that do the opposite 2×2 centre (usually yellow, but you can check the corner colours to make sure). The algorithm to move pieces from the front face to the top while the white face remains intact at the bottom: **r U2 r’**, **r U r’** or **r U’ r’** (**r** means you have to rotate the two right layers together). This will bring F_{7} F_{11} pair to the U_{10} U_{6} positions. In the last step you can place the yellow pieces in F_{7} F_{11} U_{7} U_{11} positions and do a **r U2 r’**.

When white and yellow centres are done check the corner pieces to figure out the locations of the other four centres related to each other. Hold the cube in your hands with the white and yellow centres facing right and left. Do the next 4 centres one-by-one using the previous algorithms not messing up the already solved pieces. When the step is complete double check that the centres are on the right place.

#### 2. Pair the corresponding edge pieces

Using the **u L` U` L u`** (and it’s symmetric: **u’ R U R’ u**) algorithm get every edge piece next to its pair. Before using this algorithm make sure there are no paired edges on the **left-top edge** of the cube, because these will be messed up (also check the right-top before applying the symmetric algorithm). You can use the **d R F` U R` F d`** algorithm if the corresponding edges are facing each other. This algorithm is not messing up other pieces.

#### 3. Solve the Cube like a 3x3x3

The puzzle now can be seen as a scrambled 3x3x3 Rubik’s Cube, solve it like that. If you don’t know how to do that find the beginner’s method here or use the online Rubik’s solver to finish the solution of the 4x4x4 cube.

#### 4. Solve parities

Usually you will be facing a parity. Some pieces are switched or oriented in the wrong way. We have long algorithms to fix these issues.

**Notation:**

F = outer front face

f = 2 front layers together

2F = inner front layer*These by themselves mean a clockwise rotation, half turn if followed by 2 and counterclockwise rotation if followed by an apostrophe.*

To switch U_{1} and U_{16} do the algorithm:

**r2 2F2 U2 f2 – D r2 U2 f2 – U’ f2 L2 U2 – B2 l2 U**

To swap U_{13} and U_{16}:

**R U’ R B2 – L’ D L B2 R2 – U 2R2 F2 2R2 – f2 2R2 2F2**

Reorient **14** and **15**:

**r2 B2 U2 l – U2 r’ U2 r – U2 F2 r F2 – l’ B2 r2**