Things every cuber should know
In addition to the notation introduced in the beginner tutorial, you should also learn these if you wish to become serious about cubing.
Double layer turns
If you see a lower case letter (e.g. r, f) it means to turn that face as well as the layer parallel to it. On big cubes (4x4x4, 5x5x5) lower case letters denote inner slices.
Cube rotations: x, y, z
The x axis is the axis perpendicular to and coming out of the R face. The y axis comes out the U face, and the z axis comes out the F face. When x, y or z are used in an algorithm, it means to rotate the whole cube with respect to that axis (x would mean clockwise, x' counter-clockwise, and x2 180 degrees).
Slice turns: M, S, E
M is the middle slice between the R and L faces, S between F and B, and E between U and D.
The Japanese cubers do things a little differently. If you end up on a Japanese cuber's site, note that they denote double layer turns with a w (e.g. Rw, Fw). Lower case letters for them mean cube rotations. A lower case r means to turn the whole cube in the direction you'd normally turn R.
Making pretty patterns
Some patterns every cuber should know how to do. Start with a solved cube. For the "checkerboard" pattern, apply M2 E2 S2. For "dots," apply M S M' S'.
On a normal cube with solid colors the orientation of the centers on a finished cube doesn't matter. However you may have cubes that have pictures on each side, and when you finish solving the cube you may have to orient the centers so that they're all facing the right way.
Turn one center clockwise and an adjacent center counterclockwise
Hold the cube so that Center 1 is on the U face and Center 2 is on the L face. Apply M E M' (U1) M E' M' (U2), where U1 is the direction to rotate Center 1 and U2 is the direction to rotate Center 2.
Turn a center 180 degrees
To turn the U center 180 degrees, do (U R L U2 R' L')*2.
To turn the U and F centers 180 degrees, do (R U' R' F)*6.
How to determine if your cube is unsolvable
If you take your cube apart and reassemble it randomly, you only have a 1 in 12 chance of reassembling it so that it is solvable. Usually when you get to the last layer you will be able to tell. Your cube is unsolvable if:
- Exactly one edge piece is correctly (or incorrectly) oriented and the first two layers are correct
- Two corners or two edges need to be switched and everything else is correct
- When you're at the last layer, look at the corners. Assign each correctly oriented corner a value of 0, each corner that needs to be rotated clockwise a value of +1 and each corner that needs to be rotated counter-clockwise a value of -1. The sum of the values for all the corners should be -3, 0 or 3. If it is anything else, your cube is unsolvable.
Basic cube maintenance
To take your cube apart, turn a face 45 degrees. Lift up an edge piece on the rotated face with your thumb and pull it upward as you push down on the pieces directly below it. You may need a flat instrument like a key to pry it out (gently! Don't force it or you might break something. And don't use anything too sharp as the plastic is pretty soft). Once the edge is out the rest of the pieces come out easily. When reassembling, insert the edge piece last. Push it down the same way it came out, and it should pop neatly back in place.
Lubing your cube
Lubricating your cube does wonders when you're going for speed. Check the label; use silicon based lubricant, not petroleum based, as petroleum damages the plastic. Don't use WD-40. To lube your cube, pop out an edge piece and spray a bit in the hole. Put the piece back in and turn the cube randomly for a while to spread it to all the moving parts. You can find silicon spray at Wal-Mart or auto supply stores.
Another way to improve your cube's performance is to clean it out. All the parts moving around in the cube wear down the plastic and the dust accumulates inside. Every few weeks or so, take your cube apart and use something like an old toothbrush to clean off all the dust. I've found that microfiber car towels are excellent for this purpose. It's also a good idea to clean it before lubing your cube for the first time.
The original Rubik's cubes in the 1980s came with sturdy vinyl stickers that didn't peel or fade. Today's cubes have paper stickers with a thin plastic film over them that start peeling after about a month of use.
Chris Liccardi's Cubesmith is a good place to get replacement stickers for Rubik's cubes and other puzzles. They're good quality stickers and last much longer than the stickers that come with the cube. If you prefer them, he also makes Lexan tiles which are even more resistant to chipping and peeling.
Where to get Rubik's cubes
In the US, Wal-Mart or Target are pretty good bets. A lot of toy stores carry them, but if you can't find any where you live, you can always try online. You can buy cubes and cube accessories (extra stickers, cube lube, novelty cubes, etc.) from Rubiks.com.
A few Chinese companies like Cube4you and 9sPuzzles have become major suppliers of DIY cubes. These aren't official Rubik's branded cubes, but a lot of cubers these days like them because you can assemble and tune them to your liking, rather than hoping for luck of the draw with store-bought cubes. Shipping tends to be expensive and slow if you don't live in Asia though. PuzzleProz's eBay store is also a reliable source of DIY cubes and other puzzles.