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The Piececlopedia is intended as a scholarly reference concerning the history and naming conventions of pieces used in Chess variants. But it is not a set of standards concerning what you must call pieces in newly invented games.

Piececlopedia: Cannon

Historical notes

The Cannon comes from Xiangqi, Chinese Chess. It is indiginous to China, where gun powder and cannons were both invented. Fairy Chess problemists commonly call it a Pao, which is a transliteration of its Chinese name. But in Chess variants, it is more commonly called a Cannon.

The Cannon has been used in the following variants. Except for two games by the same person, it has been called a Cannon in every one of these variants.


When the Cannon does not take, it moves like a Rook, i.e., on an orthogonal line an arbitrary number of empty squares. When it takes, it must jump: when taking, the Cannon also moves over an orthogonal line, jumps over the first piece it meets (which may either be friendly or from the opponent) and then continues over the line until the next piece it sees: if that is from the opponent, the Cannon can take it by moving to that position.

Movement diagram


The diagram above shows the Cannon's legal moves. The Cannon on d5 can take the Bishop on b5 or the Rook on d1, and it can move to any other space marked with a square border inside it.

Vocabulary: Screen

To make a capture, a Cannon must jump over a screen. This is an intervening piece, which may be of either color, that must stand between the Cannon and its target. Without a screen between the Cannon and its target, it cannot capture the piece. The Cannon moves as a Rook without capturing, and once it jumps over its screen, it continues along as a Rook but only to capture. It cannot jump the screen to make a non-capturing move. When a Cannon attacks, it can be blocked by two pieces, or the opponent can defuse the Cannon's attack by moving the screen out of its path.

While a Cannon uses a screen only for capturing, another type of piece, known as a hopper, requires a screen for both moving and capturing. The best known hopper is the Grasshopper. Other pieces that use a screen only for capturing include the Vao and the Leo.


Click on an image to view the full piece set it belongs to.

Abstract Set Alfaerie Set
Motif Set Cazaux Set
Traditional Chinese Set National Standard Chinese Set
Iconographic Chinese Set

This is an item in the Piececlopedia: an overview of different (fairy) chess pieces.
Written by Fergus Duniho and Hans Bodlaender. Diagram by Ben Good.
WWW page created: September 7, 1998. Last modified: December 15, 2001.