The Roux method step by step
The Roux method was developed by Gilles Roux. Instead of solving layer by layer like CFOP, it builds blocks and leaves the middle slice for last. Pick a step in the tool to see on the 3D cube what it solves.
1. First block
A 1 x 2 x 3 block on the left: the left center, three edges and two corners on the bottom two layers of the left side. It is built intuitively.
2. Second block
The same block on the right side, built without breaking the first one, mostly with R, r, U and M turns. After this step the middle slice and the top layer are still free.
3. CMLL
Corners of the last layer: the four top corners are turned and placed in one algorithm, ignoring the edges. Full CMLL has 42 cases; our test confirms that the four top corners have 42 arrangements up to turns of the top, apart from solved. Beginners do it in two steps: orient the corners (the seven OLL cross cases work for this, since edges do not matter yet), then permute them.
4. Last six edges (LSE)
The four top edges and the two middle-slice edges at the front and back bottom, solved with only M and U turns. M and U turns never disturb the two blocks, and the top corners only need a final U turn, which keeps this step short to execute.
Roux compared with CFOP
Roux uses far fewer memorized algorithms than full CFOP (no full OLL or PLL), but the block building needs practice to plan. It suits people who enjoy working out solutions over learning lists. You can drill the corner algorithms with the practice mode on the OLL page and time solves with the cube timer.
Sources: Speedsolving.com wiki: Roux method. Rules checked . Found a problem? Tell us.
Questions
Who invented the Roux method?
Gilles Roux, after whom it is named.
How many algorithms does Roux need?
Only CMLL needs a real algorithm set: 42 cases for the full version, or about a dozen if you do it in two steps. Blocks and the last six edges are solved by understanding.
Is Roux harder than CFOP?
It is different: fewer algorithms, more planning. The block steps take practice, while the last six edges use only M and U turns.
Can I use Roux on a 2x2 or 4x4?
The block ideas carry over, but Roux is mainly a 3x3 method. On a 4x4 you would first reduce the cube to a 3x3.