This page is an extension of 56 Tactical Patterns That All Chess Players Should Know.
A skewer is often described as the opposite of a pin. A valuable piece is attacked and forced to move, exposing a less valuable piece behind it. Skewers frequently occur on files, ranks, and diagonals involving kings, queens, rooks, and bishops.
Here are three examples of Skewers.
Example #1

1. Qf7+ Kd8 2. Qxb7
Example #2

1. Bxg4 Qxg4 2. Qc8+
Example #3

1. Rxc4+