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On a 3x3 cube, you can memorize 50–80 algorithms (CFOP, Roux, ZZ). On a 7x7x7, the number of potential parity errors and center-building patterns explodes. A dedicated provides: xnxnxnxn cube algorithms pdf nxnxn rubik cube link
: Solve the remaining cube as you would a 3x3, though you may encounter "parity" cases (unique to even-numbered cubes like 4x4 or 6x6). After scouring speedcubing forums