Rubik's Cube Move NotationsIn order to convey a certain turn or a sequence of turns around the cube through writing, there are certain agreed key letters that specify exactly what move should be made: There are 6 different letters for turning the Rubik's cube, each for the 6 faces of the Rubik's cube to be turned:
- F (front): the face facing the solver.
- B (back): the back face.
- R (right): the right face.
- L (left): the left face.
- U (up): the upper face.
- D (down): the face opposite to the upper face.
The letter means turning a single turn, (90°), clockwise, the corresponding face.
Letter followed by an apostrophe mark (') (known as "prime") means turning the corresponding face a single turn, (90°), counter-clockwise.
Letter followed by "2" means turning the corresponding face 2 single turns (180°). The direction of the turning does not matter here. (However sometimes notations such R2' do appear – mostly for speedcubing reasons, to suggest the speedy and flowing way to execute an algorithm)
These notation marks will always be in Capital letters. The reason for that is that there are different meanings for small letters:
Double Layer TurnsA small letter means turning the face along with its corresponding middle layer, making it a double layer turn. The reason for doing such moves is that it can reduce the need of cube rotations (For example: l is equal for doing just R and x' - which is a cube rotation mark, explanation ahead). It is also accepted to use a capital letter + w instead of small letter (For example: Rw; it is identical to r). Small letters can be followed by a prime ('), or 2 just like the regular turns and means the same.
Middle Layer TurnsThere are 3 different middle layer possible turns in the Rubiks cube, presented by letters (Capital only). Only 1 out of the 3 is popular in common algorithms, while the other 2 are rarely used. Still here are the notations:
- M (middle): the middle layer parallel to the R & L faces.
- E (equator): the middle layer parallel to the U & D faces.
- S (side): the middle layer parallel to the F & B faces.
The middle layer turns can be followed by a prime ('), or 2, just like the regular turns. Middle layer turns are always written in capital letters.
Cube RotationsThese are not actual turns, and is meant to instruct a rotation of whole the cube. Sometimes making a cube rotation allows executing much more convenient turns, like turning the R face, instead of the B face. There are 3 possible axes to rotate the cube on: The X, Y & Z axes. Just like in math. Those are also the letters used for these rotations. Best way to remember the rotations is just thinking about a 3D function graph:
- x : rotating the cube on the X axis. (R & L faces remain intact)
- y : rotating the cube on the Y axis. (U & D faces remain intact)
- z : rotating the cube on the Z axis. (F & B faces remain intact)
Cube rotations usually written as small letters, but it doesn't have a meaning and they could possibly by written as capital letters – same meaning.
Cube rotations can be followed by a prime (') meaning rotating the cube a quarter rotation (90°) on the corresponding axis counter-clockwise, or followed by 2 which means rotating the cube 180° on the axis.
Tip: If you're having difficulties in finding the right CW/C-CW direction of a face (like B or D faces for example), rotate temporarily the cube so that face will become the F face which is the easiest face to determine the CW/CCW direction. Just image a clock on the face and think where the hand would go to)
A sequence of turns in a row is represented by a sequence of letters, and called an algorithm.