Rubik's Cube Notation Explained: What R, U' and F2 Actually Mean

Cube notation is far simpler than it looks. Each letter names one of the six faces — Up, Down, Left, Right, Front and Back. A letter on its own means turn that face a quarter turn clockwise, as if you were looking straight at it. An apostrophe (R', said "R prime") means anticlockwise instead, and a 2 (R2) means a half turn — 180°, direction irrelevant. That's the entire system.

This is Singmaster notation, standardised around 1981 by the mathematician David Singmaster while the world was still in the grip of the original cube craze. Its quiet genius is that it never mentions colour: every move is relative to how you happen to be holding the cube, so one written algorithm works for any colour scheme, any brand of cube, and any grip.

Read a sequence left to right, one move at a time. The famous four-move trigger R U R' U' says: right face clockwise, top clockwise, right face anticlockwise, top anticlockwise. Every algorithm you will ever meet — from the beginner method to world-record solves — is written in this alphabet.

The six faces

The letters describe positions, not colours. Whatever is facing you right now is F; if you turn the whole cube in your hands, the letters follow your new grip.

Primes and doubles: R vs R' vs R2

Each face letter comes in three flavours. R is a quarter turn clockwise, R' is a quarter turn anticlockwise, and R2 is a half turn — and since 180° lands in the same place either way, an R2 can be turned in whichever direction your fingers prefer.

The rule that makes it all unambiguous: clockwise means clockwise as seen by someone looking directly at that face. Imagine your eye floating in front of the face you're about to turn. For F, R and U that feels natural. The classic trip-up is B and D: a clockwise B is judged from behind the cube, so from where you're sitting it appears to rotate anticlockwise — and a clockwise D is judged from below, so looking down at it from above it also appears reversed. If an algorithm mysteriously refuses to work, a B or D turned the wrong way is the first thing to check.

Slice moves: M, E and S

The three middle layers get letters too. They're rarer in beginner material but everywhere in advanced methods:

• M (middle) — the vertical slice between L and R. It turns in the same direction as L.
• E (equator) — the horizontal slice between U and D. It follows D.
• S (standing) — the slice between F and B. It follows F.

Primes and doubles apply exactly as before: M' turns the middle slice the opposite way to L, M2 is a half turn. If you ever explore the Roux method, expect to meet M constantly — its entire final phase is built from M and U moves alone. We cover what that trade-off buys you in CFOP vs Roux vs the beginner method.

Whole-cube rotations: x, y and z

Sometimes an algorithm asks you to turn the entire cube in your hands — no layers move relative to each other, you just change your grip. Those are the lowercase letters x, y and z, and each one borrows its direction from a face you already know:

• x rotates the whole cube the way an R turns (the front face rolls up and over the top; prime for the reverse).
• y rotates the whole cube the way a U turns (spin it flat, like a lazy Susan).
• z rotates the whole cube the way an F turns (cartwheel it clockwise as you look at it).

Rotations don't change the scramble at all — they only change which face is currently called F. Algorithm writers use them to put the interesting pieces where your fingers are fastest.

Wide moves: Rw and lowercase r

A wide move turns two layers at once: the face and the slice next to it. You'll see it written either as Rw or as a lowercase r — both mean "turn the right-hand two layers together". On a 3×3 that's the same as doing R and M' in one motion, and some fingertrick-friendly algorithms are written that way on purpose. Wide moves really come into their own on 4×4 cubes and bigger, where grabbing multiple layers is the everyday way to move pieces around. As ever, Rw' and Rw2 mean exactly what you'd now guess.

Where to practise it

Notation sticks fastest when every symbol is attached to a movement you've actually made. Two free ways to do that here:

The Learn page starts with the interactive notation lab — press any of the eighteen moves and watch a 3D cube perform it — then teaches the full beginner method with animated demos. And when you paint your own scrambled cube into the solver, it doesn't just flash symbols at you: every move in the solution is spelled out in plain English ("right (orange) face — quarter turn clockwise") as the 3D cube plays it, so the notation and the motion sink in together. A few minutes of that and R U R' U' stops being code — it's just your hands.