# Blockbuilding

**Blockbuilding** is a method for intuitive solving by creating groups of blocks and joining them together. It is used in the sub-steps of many methods including: Petrus, Heise, Roux and ZZ. Blockbuilding is an alternative to using algorithms.

## Blockbuilding on big cubes

Most people use the reduction method to speedsolve the 5x5x5 cube but a few use direct solving to complete the puzzle. While doing that, there are some situations that does not occur on the 4x4x4 cube (or any even-layered cube). Below is a listing of some algorithms. They are also useful for 5x5x5 BLD.

### PLLs

- Rw2 Fw2 U2 r2 U2 Fw2 Rw2: PLL parity (wing edges)
- x Rw2 Uw2 x U2 l2 U2 x' Uw2 Rw2 (x'): same as previous
- F2 U m' U2 m U F2: U-PLL (center edges)
- F2 U' m' U2 m U' F2: U-PLL' (center edges)
- m2 U m2 U2 m2 U m2: H-PLL (center edges)
- Fw2 m2 Fw2 U2 m2 U m2 U m2: Z-PLL (center edges)