The **Rubik's Revenge**, also known as the 4x4, is the sequel cube to the Rubik's Cube. The idea of the Rubik's Revenge is that it has more combinations and ways to solve, which also makes it harder. Although it has 16 pieces on each side, it is solved with a very similar method to the 3x3x3.

The unicode character U+25A6 (▦) resembles this cube.

## HistoryEdit

The Rubik's Revenge was patented by Péter Sebestény on December 20th 1981. It was originally going to be named the Péter Sebestény Cube, until a last minute change was made to attract fans of the original Rubik's Cube.

## DesignEdit

Since the Rubik's Revenge has 16 cubies on one side, it is built differently than the 3x3x3. Unlike a 3x3x3 Cube, the RR has 4 center cubies on each side, and 12 edge cubies. The 3x3x3 is built on a cross-like object, with the center pieces fixed into place and the edges interlocking with each other, but the RR is built on a spherical body. The sphere that the RR is built on has 8 pieces lifted approximately 0.25" off of the sphere. The 8 pieces can be loosened or tightened with a screwdriver. The center cubies are snapped in where 4 pieces make one point. The edge cubies then interlock with the center pieces from 2 sides. The corner cubies fit between 2 sets of edge cubies. This design makes it harder to speedcube. To speedcube the RR, people make their own custom built Rubik's Cubes or buy higher quality 4x4x4's.

## Solving the Rubik's RevengeEdit

The Rubik's Revenge can be solved with formulas very similar to the 3x3x3 cube. The only two problems are that unlike the 3x3x3 cube, this cube has the center cubie is split into 4 smaller cubies, and 12 edge pieces split into 2 smaller cubies each. To solve the cube, you must solve the center cubies, by making a 2x2 square on the center of each side of the cube, each representing the color of that side in its solved state. You must then solve the edge pairs by placing each color pair on one edge of the cube together. After solving those, you can solve the cube with any method used on the 3X3X3 cube. The final step is to fix what is called a parity. The 4x4x4 can have two possible problems not found on the 3x3x3. The first is two edge pieces reversed on one edge, resulting in the colors for that edge not matching the rest of the cubies on either face. The second is two edge pairs, known as dedges, being flipped with each other. Two more algorithms are required to fix these parities.

## World RecordsEdit

The world record for fastest solve is 18.42 seconds, set by Max Park of the United States on 27 May 2018 at SacCubing IV 2018. The world record for fastest average of five solves (excluding fastest and slowest solves) is 21.13 seconds, also set by Park on 27 May 2018 at SacCubing IV 2018. The world record for fastest blindfolded solve (including inspection time) is 1 minute, 29.42 seconds, set by Stanley Chapel of the United States on 18 May 2018 at Great Lakes Championship 2018.

## TriviaEdit

- An early design of a Rubik's Revenge shows blue opposite with white, and yellow opposite with green. It is currently now blue opposite green, and yellow opposite white.