often familiar to beginner solvers. True two-look requires only ten algorithms, typically named for the shape or "case" shown by the top-color facelets that is solved by the algorithm. Three algorithms - Dot, L and Line - are used for edge orientation, and seven - Sune, Antisune, Pi, H, Bowtie, Headlights and T - for corner orientation. Edge orientation in two-look is commonly taught as two algorithms, one of which is a simple variation of the other; the Dot case is solved by performing both algorithms consecutively. Additionally, the required algorithms for corner orientation can be reduced to just two, the Sune and Antisune, as all other permutations can be solved either by performing two Sunes or a Sune followed by an Antisune. Additional algorithms, more efficient than the Sune-Antisune sequences, can be learned at the solver's own pace. Permute Last Layer (PLL) The final stage involves moving the pieces of the top layer while preserving their orientation. There are a total of 21 algorithms for this stage. They are distinguished by letter names, often based on what they look like with arrows representing what pieces are swapped around (e.g., A-perm, F-perm, T-perm, etc.). "Two-look" PLL solves the corners first, followed by the edges, and requires learning just six algorithms of the full PLL set. The most common subset uses the A-perm and E-perm to solve corners (as these algorithms only permute the corners), then the U-perm (in clockwise and counter-clockwise variants), H-perm and Z-perm for edges. However, as corners are solved first in two-look, the relative position of edges is unimportant, and so algorithms that permute both corners and edges can be used to solve corners. The J, T, F, and R-perms are all valid substitutes for the A-perm, while the N, V and Y-perms can do the same job as the E-perm. Even fewer algorithms can be used to solve PLL - as few as two, such as the A-perm and U-perm - at the expense of having to repeat these algorithms to solve other cases, with additional "looks" to identify the next step. Skipped Stages Depending on the initial state of the cube and the exact moves made in previous stages, it is possible to complete one stage in such a way that the next stage is also already complete. This is known as a "skip", commonly referred to specifically by the stage that isn't required in