All events · 3x3x3 Fewest Moves · Practise · Algorithms
FMC · Intermediate
Edge orientation, domino reduction, and half-turn finishes. Solutions under 40 moves.
Move sequences on this page were checked in a cube simulator (cubing.js): they are legal and, where the text says so, do what it claims. Strategy advice is guidance, not machine-checked. Group facts on this page (which moves keep edges oriented, and so on) were checked by simulation.
Edge orientation (EO)
Pick an axis (usually front-back). The edges are oriented when every edge can be solved using only R, L, U and D turns (and F2, B2). The moves U, D, R, L, F2 and B2 keep every edge oriented; F and B flip four edges. So once you have EO, avoid quarter turns of F and B.
Domino reduction (DR)
DR means EO plus all corners oriented plus the four middle-slice edges in the middle slice. After DR, the moves U, D, R2, L2, F2 and B2 keep all of that intact. That leaves a much smaller set of cube positions to solve.
Half-turn reduction (HTR)
HTR is the stage where the cube can be solved with half turns only. Reaching it is the key to short solutions, because from there you only need half turns to finish.