refers to specific cube states on a 4x4 Rubik's Cube (Rubik's Revenge) that are physically impossible to encounter on a standard 3x3 cube. These "illegal" states occur because the 4x4 cube has even layers and lacks a fixed center piece, allowing for configurations that violate the basic laws of 3x3 edge and corner orientation. What is 4x4 Parity?
| Parity Type | Appearance (on last layer) | Fix Algorithm (short version) | |-------------|----------------------------|-------------------------------| | OLL | One edge pair flipped | r' U2 l F2 l' F2 r2 U2 r U2 r' U2 F2 r2 F2 | | PLL | Two opposite edge pairs swapped | 2R2 U2 2R2 Uw2 2R2 Uw2 | | PLL adjacent | Two adjacent edge pairs swapped | U [opposite swap] U' | 4x4 parity
(Orientation of Last Layer parity) – An odd number of edge pieces are flipped, making it impossible to solve the last layer with standard 3×3 algorithms. Appearance: You have a single edge pair flipped, or an impossible OLL case like one edge flipped in place. refers to specific cube states on a 4x4