Corner chain

Corner chain
Chain type	Extension

A corner chain is a simple chain wherein one group pops and sends a petal in a perpendicular direction to complete the next link of the chain. They are frequently set up in the corners of the board during blueprint opener chains that proceed around the board's edge. With respect to these chains, they operate similarly to the concept of the transition from Puyo Puyo, in that you use them to continue after encountering the wall.

A corner chain is known as offset if the next link in the chain is set off from a petal which is not on the opposite side of the link from the point where the current link was set off from. For example, the purple-to-green portion of the following diagram is an offset corner chain:

In particular, the offset corner chain is the basic building block of the staircase and pinwheel patterns.