Detailed instructions for working a group puzzle of type 'Thunderclaps'

This is a signature puzzle named 'Thunderclaps'

The 12 elements in each group of this type of puzzle are: T, H, U, N, D, E, R, C, L, A, P, and S.

Every group in the puzzle must contain exactly this set of elements.

Each row is a group numbered as shown in this Thunderclaps figure.

In a Thunderclaps puzzle, each row is a group numbered as shown in the figure above.

Each column is a group numbered as shown in this Thunderclaps figure.

In a Thunderclaps puzzle, each column is a group numbered as shown in the figure above.

Each 4x3 rectangle is a group numbered as shown in this Thunderclaps figure.

In a Thunderclaps puzzle, each 4x3 rectangle is a group numbered as shown in the figure above.

Each eye is a group numbered as shown in this Thunderclaps figure.

In a Thunderclaps puzzle, each eye is a group numbered as shown in the figure above.

The elements that make up the smile are a group and are marked with '1st' in this Thunderclaps figure.

In a Thunderclaps puzzle, the elements that make up the smile are a group and are marked with '1st' in the figure above.