How to Solve a Rubik's Cube (Easy Move Notation)
Four Parts:First LayerMiddle LayerLast LayerNotations
The Rubik's Cube can be very frustrating and may seem next to impossible to restore to its original configuration. However, once you know a few algorithms, it is very easy to solve. The method described in this article is the layer method: first you solve one face of the cube (first layer), then the middle layer, and finally the last layer.
Steps
Part 1 First Layer
- 1Familiarize yourself with the Notations at the bottom of the page.
- 2Choose one face to start with. In the examples that will follow, the color for the first layer is white.
- 3Solve the cross. Find the side with the white square in the center and put it on top. Set into position the four edge pieces that contain white. (You should be able to do this by yourself without needing algorithms.) All four edge pieces can be placed in a maximum of eight moves (five or six in general).
- Place the cross at the bottom. Turn the cube over 180° so that the cross is now on the bottom.
- 4Solve the four corners of the first layer, one by one. You should also be able to place the corners without needing algorithms. To get you started, here is an example of one corner being solved:
- At the end of this step, the first layer should be complete, with a solid color (in this case, white) at the bottom.
- 5Verify your first layer is correct. You should now have the first layer complete and look like this (from the bottom side):
Part 2 Middle Layer
- 1Place the four edges of the middle layer. Those edge pieces are the ones that do not contain yellow in our example. You need to know only one algorithm to solve the middle layer. The second algorithm is symmetrical to the first.
- If the edge piece is located in the last layer :
(1.a) (1.b)
symmetrical to (1.a) - If the edge piece is in the middle layer but in the wrong place or with the wrong orientation, simply use the same algorithm to place any other edge piece in its position. Your edge piece will then be in the last layer, and you just have to use the algorithm again to position it properly in the middle layer.
- If the edge piece is located in the last layer :
- 2Verify correct positioning. Your cube should now have the first two layers complete and look like this (from the bottom side) :
Part 3 Last Layer
- 1Permute the corners. At this step, our goal is to place the corners of the last layer in their correct position, regardless of their orientation.
- Locate two adjacent corners that share a color other than the color of the top layer (other than yellow in our case).
- Turn the top layer until these two corners are on the correct color side, facing you. For instance, if the two adjacent corners both contain red, turn the top layer until those two corners are on the red side of the cube. Note that on the other side, the two corners of the top layer will both contain the color of that side as well (orange in our example).
- Determine whether the two corners of the front side are in their correct position, and swap them if needed. In our example, the right side is green, and the left side is blue. Therefore the front corner on the right must contain green, and the front corner on the left must contain blue. If it is not the case, you will need to swap those two corners with the following algorithm:
Swap 1 and 2 : (2.a) - Do the same with the two corners at the back. Turn the cube around to place the other side (orange) in front of you. Swap the two front corners if needed.
- As an alternative, if you notice that both the front pair and the back pair of corners need to be swapped, you can do it with only one algorithm (note the huge similarity with the previous algorithm):
Swap 1 with 2 and 3 with 4 : (2.b)
- 2Orient the corners. Locate each top color facelet of the corners (yellow in our case). You need to know only one algorithm to orient the corners:
(3.a) - The algorithm will rotate three corners on themselves at once (from the side to the top). The blue arrows show which three corners you are turning, and in which direction (clockwise). If the yellow stickers are the way shown on the pictures and you perform the algorithm once, you should end up with the four yellow stickers on top :
- It is also convenient to use the symmetrical algorithm (here the red arrows are counter-clockwise turns):
(3.b)
Symmetrical to (3.a) - Note: performing one of these algorithms twice is equivalent to performing the other. In some cases, you will need to perform the algorithm more than once :
- Two correctly oriented corners :
= = + = = + = = + - No correctly oriented corner :
= = + = = + - More generally, apply (3.a) in those cases:
Two correctly oriented corners : No correctly oriented corner :
- The algorithm will rotate three corners on themselves at once (from the side to the top). The blue arrows show which three corners you are turning, and in which direction (clockwise). If the yellow stickers are the way shown on the pictures and you perform the algorithm once, you should end up with the four yellow stickers on top :
- 3Permute the edges. You will need to know only one algorithm for this step. Check whether one or several edges are already in the proper position (the orientation does not matter at this point).
- If all the edges are in their correct positions, you are done for this step.
- If one edge only is correctly positioned, use the following algorithm :
(4.a) - Or its symmetrical :
(4.b)
Symmetrical to (4.a)
Note : performing twice one of these algorithms is equivalent to performing the other. - If all four edges are incorrectly positioned, perform one of the two algorithms once from any side. You will then have only one edge correctly positioned.
- 4Orient the edges. You will need to know two algorithms for that last step :
Dedmore "H" Pattern (5) Dedmore "Fish" Pattern (6) - Note the DOWN, LEFT, UP, RIGHT, sequence to most of the Dedmore "H" and "Fish" algorithms. You really have only one algorithm to remember since :
(6) = + (5) + - If all four edges are flipped, perform the "H" pattern algorithm from any side, and you will have to perform that algorithm one more time to solve the cube.
- Note the DOWN, LEFT, UP, RIGHT, sequence to most of the Dedmore "H" and "Fish" algorithms. You really have only one algorithm to remember since :
- 5Congratulations! Your cube should now be solved.
Part 4 Notations
- 1This is the key to the notations used.
- The pieces that compose the Rubik's Cube are called Cubies, and the color stickers on the cubes are called facelets.
- There are three types of Cubies:
- The centers (or center pieces), at the center of each face of the Cube. There are six of them, each have one facelet
- The corners (or corner pieces), at the corners of the Cube. There are eight of them, and each have three facelets
- The edges (or edge pieces), between each pair of adjacent corners. There are 12 of them and each have 2 facelets
- Not all cubes have the same color schemes. The colors used for these illustrations is called BOY (because the Blue, Orange and Yellow faces are in clockwise order).
- White opposes yellow;
- Blue opposes green;
- Orange opposes red;
- 2This article uses two different views for the Cube:
- The 3D View, showing three sides of the Cube: the front (red), the top (yellow), and the right side (green). In Step 4, the algorithm (1.b) is illustrated with a picture showing the left side of the cube (blue), the front (red) and top (yellow).
- The Top View, showing only the top of the cube (yellow). The front side is at the bottom (red).
- The 3D View, showing three sides of the Cube: the front (red), the top (yellow), and the right side (green). In Step 4, the algorithm (1.b) is illustrated with a picture showing the left side of the cube (blue), the front (red) and top (yellow).
- 3
- 4When a facelet is grey, it means that its color is not important at the moment.
- 5The arrows (blue or red) show what the algorithm will do. In the case of the algorithm (3.a) for instance, it will rotate the three corners on themselves as shown. If the yellow facelets are as drawn on the picture, at the end of the algorithm they will be on top.
- The axis of the rotation is the big diagonal of the cube (from one corner to the corner all the way on the other side of the cube).
- Blue arrows are used for clockwise turns (algorithm (3.a)).
- Red arrows are used for counter-clockwise turns (algorithm (3.b), symmetrical to (3.a)).
- 6
- 7
Tips
- Practice. Spend some time with your cube to learn how to move pieces around. This is especially important when you are learning to solve the first layer.
- Know the colors of your cube. You must know which color is opposite which, and the order of the colors around each face. For instance, if white is on top and red in front, then you must know that blue is on the right, orange in the back, green on the left and yellow at the bottom.
- For those interested in speed cubing, or those who simply don't like how hard it is to turn pieces, it is a good idea to buy a DIY kit. The pieces of speedcubes have rounder inner corners and DIY kits allow you to adjust the tension, making it a lot easier to move pieces. Consider also lubricating your cube with a silicon based lubricant.
- You can either start with the same color to help you understand where each color goes, or try to be efficient by choosing a color for which it is easier to solve the cross.
- Locate all four edges and try to think ahead about how to move them into position without actually doing it. With practice and experience, this will teach you ways to solve it in fewer moves. And in a competition, participants are given 15 seconds to inspect their cube before the timer starts.
- Understand how the algorithms work. While executing the algorithm, try to follow key pieces around to see where they go. Try to find pattern in the algorithms. For instance :
- In the algorithms (2.a) and (2.b) used to permute corners of the top layer, you execute four moves (at the end of which all bottom layer and middle layer cubes are back in the bottom and middle layers), then turn the upper layer, and then execute the reverse of the first four moves. Therefore, this algorithm does not affect the first/bottom and middle layers.
- For the algorithms (4.a) and (4.b), note you are turning the top layer in the same direction that you need to turn the three edges.
- For the algorithm (5), Dedmore "H" Pattern, a way to remember the algorithm is to follow the path of the flipped edge on the top right and the pair of corners around it for the first half of the algorithm. And then for the other half of the algorithm, follow the other flipped edge and pair of corners. You'll notice that you perform five moves (seven moves if counting half turns as two moves), then half turn the top layer, then reverse those first five moves, and finally half turn the top layer again.
- Progress further. Once you know all the algorithms, you may want to find faster ways to solve the Rubik's:
- Solve the first layer corner along with its middle layer edge in one move.^{[1]}
- Learn algorithms to orient the last layer corners in the five cases where two (3.a/b) algorithms are necessary.
- Learn algorithms to permute the last layer edges in the two cases where no edge is correctly positioned.
- Learn the algorithm for the case where all last layer edges are flipped.
- The layer method is just one of many methods out there. For instance, the Petrus method, which solves the cube in fewer moves, consists in building a 2×2×2 block, then expanding it to a 2×2×3, correcting edge orientation, building a 2×3×3 (two layers solved), positioning the remaining corners, orienting those corners, and finally positioning the remaining edges.^{[2]}
- Progress even further. For the last layer, if you want to solve the cube fast, you will need to do the last four steps two by two. For instance, permute and orient the corners in one step, then permute and orient the edges in one step. Or you can choose to orient all corners and edges in one step, then permute all corners and edges in one step.^{[3]}
Sources and Citations
- Speedcubing.com - algorithms, videos, cube solvers, world records and ranking.
- Beginner Solution to the Rubik's Cube.
- Solution for solving the Rubik's Cube step by step illustrated method.
- Petrus Method illustrated with java animations.
- How to solve a Rubik's cube at the official Rubik's Cube website.
- ↑ http://www.speedcubing.com/f2l.html (Algorithms > First two layers)
- ↑ http://lar5.com/cube/
- ↑ http://www.speedcubing.com/finallayer.html (Algorithms > Final layer)
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