F2L situations

Stuck pieces, a piece already in place, white facing up: how to deal with them.

Goal of this step

In real solves, pieces are not always neatly on top. Three situations come up very often:

a piece is stuck in a slot (the right one or another one): take it out first;
one of the two pieces is already solved: take the other one out without disturbing it;
the corner has white facing up: twist it first so the pair can be formed.

The examples below show an efficient way to handle each of these situations. Notice that each one starts with a short trigger that turns the case into a simple situation from the previous lesson.

Cases and algorithms

The corner is in its slot but twisted; the edge is on top, on the right. Take the corner out, pair it up, then put it back.

R U' R' U R U' R'

The corner is already solved; the edge is on top, on the left.

R U' R' U' F' U F

The edge is already solved; the corner is above the slot, white facing front.

U' R U' R' U2 R U' R'

Corner above its slot, white facing up; edge on top, on the right.

R U2 R' U' R U R'

Tips

A piece stuck in the wrong slot? Take it out first with a trigger like R U R', then treat it as a top piece.
You have 4 slots to fill: start with the easiest pair, not necessarily the first one you see.
While you insert a pair, already look for the pieces of the next one: that is look-ahead.