# Edge Orientation

(Redirected from 2-axis EO)

The orientation of edges of the cube, often only EO (edge orientation). Methods such as Roux (6 edges), ZZ (all edges), and Petrus (7 edges) include this as a substep. Also other puzzles such as the Square-1 have EO as a common sub step (EO on a Square-1 is more precisely a separation of edges to the correct layers but it is always referred to as edge orientation.)

## EO on multiple axes

On 3x3x3, there are three different axis EO can be done from:

• White/Yellow front
• Green/Blue front
• Red/Orange front

### 2-axis EO

Cube with 2-axis EO

2-axis EO means that EO is performed on two axes by firstly orienting all edges on one axis and then on a different one by separating the edges that belong into the slice which goes through all faces of the EOs using only R, U, L and D moves. In the case of a Green/Blue front and Red/Orange front EO, this would mean that all E-slice edges (the E-slice is the only slice that goes through the green, orange, blue and red faces) are put into the E-slice, but not necessarily solved. This allows the edges to be solved <U, D, F2, L2, B2, R2>-gen and is used in Domino Reduction.

### 3-axis EO

Cube with 3-axis EO

3-axis EO means that EO is performed on three axes by separating all edges into their respective slices after 2-axis EO <U, D, F2, L2, B2, R2>-gen. This allows the edges to be solved using only half turns and is used in Half Turn Reduction.

## Petrus

Edge orientation in Petrus is generally solved with the 2x2x3 block in the back with only R, U, L and F moves. A more detailed explanation can be found in #See also.

## Roux

### EO Detection

If an LSE edge has the sticker with the color of the U face or the D face facing up or down, it is good/oriented. Therefore, if that sticker is not facing up or down, the edge is bad/unoriented.

### Solve EO

The bad edges can be oriented with only M and U moves. The solver usually tries to reduce the EO case to an "arrow" where only four bad edges remain, one in the D layer and the other three in the U layer. This is done because the arrow can be solved with the simple trigger M(') U(') M(') (the exact algorithm depends on the angle). For a more detailed explanation, follow the links in #See also.

## ZZ

### EO Detection

Looking at the edges on the U face, D face, F face of the E-slice, and B face of the E-slice:

• If the sticker has L/R color it's a bad edge.
• If the sticker has F/B color, look at the sticker on the other side of the edge.
* If the side sticker has U/D color, it's a bad edge.