Ever tried solving a cube and come across a case that was seemingly impossible to solve? There are in fact impossible or unsolvable Rubik's cubes, read on to learn what these cases are and how to fix them.
Corner Twist
A singular twisted corner is an impossible case to get on 3x3, and any NxN puzzle. This can occur when a 3x3 is assembled incorrectly or a corner is accidentally twisted when turning.
In order to fix this, simply grab the corner with your thumb, index, and middle fingers and turn the corner clockwise/counterclockwise.
Swapped Pieces
Two edge pieces cannot be swapped, either adjacently or opposite on a 3x3 Rubik's cube. The same can be said for two corner pieces.
In order to fix this, solve the cube firstly and identify the two pieces that are unsolvable. If they are edge pieces, put the edge pieces in the U (top) layer, and turn the 45 degrees. Take the edge out (this may require minimal force) and repeat with the other each piece. Swap these pieces and place them back into the puzzle.
However, this case can occur on bigger NxN puzzles such as 4x4, 5x5 etc., and Square-1 - this is known as parity.
Multiples of the Same Color
In images and illustrations of the Rubik's cubes, common mistakes can occur where multiples of the same color appear incorrectly. These include two of the same color on a single edge or corner piece, or more than one center color on the cube, as each center has its own color.
This is unsolvable. If you come across a real cube with multiples of the same sticker, either purchase new stickers or swap the stickers into a solve position. If it is stickerless, you may have to take the puzzle apart, use the videos above.