Peter Michaelsen writes:

It is a great pleasure for me to introduce the readers of this web site to two new chess variants, which I invented last year. The first of these, Cannon Shogi, was invented in February 1998, and the other, Cannon Chess, in July 1998. In April 1999 I made a slight revision of the initial array of the latter game.

Both games are played on the Shogi 9x9 board, Cannon Shogi with 2x20 pieces, and Cannon Chess with 2x18. If small labels are placed upon and under the pieces, the two games can easily be played with a Shogi set.

It is now also possible to play Cannon Shogi and Cannon Chess by computer. Steve Evans, who wrote the very nice Shogi Variants program, described by Rick Brown in NOST.ALGIA #371, p.30, has implemented both games, using the Zillions of Games program. Zillions, developed by Mark Lefler and Jeff Mallett, contains a generic board-game engine that can learn new games on the spot and play them. Game rules are stored in text documents that can be edited. So far, over 500 puzzles, games and variants have been implemented (for more information, see the home page of Zillions: <http://www.zillions-of-games.com>, from where a lot of new implementations can be downloaded).

Cannon Shogi

Cannon Shogi is similar to Ortho-Shogi, but with some differences, as is clear from this picture of the initial array:

The 2x5 Pawns are placed on the a-, c-, e-, g-, and i-files.

A Pawn moves and captures a single square forward or sideways, like the Soldier of Korean Chess. It promotes (optionally) to a Gold General when making a move that begins or ends in the last 3 ranks of the board.

On the 2nd and 8th rank 2x4 cannons are situated. The four cannons of each player are all different.

The diagonal Bishop is flanked by two orthogonal cannons; the orthogonal Rook is flanked by two diagonal cannons.

The Gold Cannons on d2/f8 move like Rooks, by sliding any number of squares along a row or column, but they can capture an enemy only if there is another piece (of either side) in between. Thus to capture they leap over the intervening piece and land on the enemy piece, like a cannonball. This is the same move and capture as the Cannon (Pao) of Chinese Chess (Xiangqi).

The Silver Cannons on c2/g8 capture like Gold Cannons, but can only move by leaping over an intervening piece, called a "screen". They move and capture like the Cannon of Korean Chess.

The Copper Cannons on g2/c8 move like Bishops, by sliding any number of squares along a diagonal, but they can capture an enemy only if there is another piece (of either side) in between. They capture by leaping over an intervening piece, and have the same powers as the Cannon of Chinese Chess, but in a diagonal rather than orthogonal direction.

The Iron Cannons on f2/d8 capture like Copper Cannons, but can only move by leaping over a screen. They have the same powers as the Cannon of Korean Chess, but in a diagonal rather than orthogonal direction.

A Cannon promotes (optionally) to a Flying Cannon when making a move that begins or ends in the last 3 ranks. It acquires additional powers:

A Flying Gold Cannon and a Flying Silver Cannon can move orthogonally over whole rows and is able to leap one piece by moving. The FGC and FSC can also move one square diagonally and, besides, move or capture two squares diagonally, by leaping an adjacent piece.

A Flying Copper Cannon and a Flying Iron Cannon can move diagonally over whole rows and is able to leap one piece by moving. The FCC and FIC can also move one square orthogonally and, besides, move or capture two squares orthogonally, by leaping an adjacent piece.

All other pieces move, capture and promote like Shogi pieces. Captured pieces are added to the capturer's "reserve", an army of pieces which can be reintroduced into play on the capturer's side. Like in Shogi, a Knight or Lance may not be dropped on a square from which it will never be able to move. Contrary to Shogi, there are no Pawn drop restrictions: Pawns may be placed on a file that already contains an unpromoted Pawn, and may also be dropped with mate.

With Steve Evans' Zillions implementation of Cannon Shogi one can play several variants: Cannon Shogi with Pawn drop restrictions, Cannon Shogi with swapped Cannons (GCs on c2/g8, SCs on d2/f8, CCs on f2/d8, ICs on g2/c8), and, finally, Cannon Shogi with "Korean" Cannons, ie.: Cannons cannot leap or capture other Cannons.

With the introduction of the cannons of Chinese and Korean Chess, as well as their diagonal counterparts, I want to add a new dimension to the classical game of Shogi. With a pawn array similar to the one used in Chinese and Korean Chess, the opening game tends to be much more tactical and explosive than in ordinary Shogi. Not only because of their high number, the cannons dominate play more than in Xiangqi and Changgi. Because of the drops, they are more mobile and dangerous in all phases of the game. They may be weakened a little on board, as more and more pieces are captured and kept in hand, but may still be very useful when dropped on the board again, or when other pieces are dropped in front of them.

I made the Pawns move and capture sideways as well as forwards, because I thought that they needed some compensation, being only 2x5 against 2x15 officers.

Game transcripts

I quote: "Cannon Shogi is a wild game. The cannons remind me of the jumping generals of tenjiku shogi. With so little experience of this game it is difficult to evaluate these games properly, and these few comments below are made from a shogi perspective.

Cannon Shogi game 1

Cannon Shogi game 2

Because of the power of the cannons there seems to be little point in castling in this game, because the protective pieces could prove to be a liability. It would seem prudent to give the king as much space as possible. The preponderance of powerful pieces would seem to make this a game almost entirely of tactics rather than strategy. However, my knowledge of the game is too little to have any confidence in such statements."

From the first two games one get the impression that the Knight, but not the Lance play a role in Cannon Shogi. The next two games show, however, that the Lance likewise can be an important piece.

Cannon Shogi game 3

Cannon Shogi game 4

Cannon Chess

Captured pieces may be reintroduced into play on the capturer's side, like in Shogi. Like in Micro Shogi, they may be dropped onto any vacant square on the board in either of the piece's two forms.

One of the most difficult problems one faces in Cannon Chess is to decide, if a piece should change state or not, and if a captured piece should be dropped onto the board again in one state or another.

In Cannon Chess the pieces loose their original cannon power, when they change to their alternative form. As a compensation they gain the power of well-known Orthochess pieces like Rook, Knight, Bishop, Queen and King. Of the promoted pieces only the Gold General retains the cannon power it had in its original state (as Silver General), but only at a short distance (=the short cannon leap of the Iron Cannon). In the initial array none of the pieces are able to capture at a long distance, except when making cannon leaps.

This picture shows the standard initial array, but the players are at liberty, before moving, to interchange the positions of their Copper Generals and Copper Cannons on their left OR right side of the board, resulting in 9 possible arrays.

Initial array

Game Pieces

Iron Cannon moves 1 square in 8 directions + 2 squares in 8 directions by leaping an adjacent piece. Captures by making a 2 squares leap in any direction over an adjacent piece. Can optionally change to an Iron General, which moves and captures 1 square in all 8 directions, like the King in Chess/Shogi.

Copper Cannon moves diagonally over whole rows and is able to leap one piece, when moving. Captures diagonally over whole rows by leaping one piece. Can optionally change to a Bishop, which moves and captures diagonally over whole rows, like the Bishop in Chess/Shogi.

Silver Cannon moves orthogonally over whole rows and is able to leap one piece, when moving. Captures orthogonally over whole rows by leaping one piece. Can optionally change to a Rook, which moves and captures orthogonally over whole rows, like the Rook in Chess/Shogi.

Gold Cannon (=Copper Cannon+Silver Cannon) moves diagonally and orthogonally over whole rows and is able to leap one piece, when moving. Captures diagonally and orthogonally over whole rows by leaping one piece. Can optionally change to a Queen (=Bishop+Rook), which moves and captures diagonally and orthogonally over whole rows, like the Queen in Chess/Free King in Chu Shogi.

Copper General (=Iron Cannon+Iron General) moves and captures 1 square in 8 directions + 2 squares in 8 directions by leaping an adjacent piece. Can optionally change to a Knight, which moves and captures directly to the opposite corner of a 2x3 rectangle, like the Knight in Chess.

Silver General (=Gold Cannon+Iron General) moves diagonally and orthogonally over whole rows and is able to leap one piece, when moving. Captures 1 square in 8 directions, and, by leaping one piece, over whole rows in 8 directions. Can optionally change to a Gold General (=Iron Cannon+Queen), which moves and captures diagonally and orthogonally over whole rows and is able to move and capture 2 squares in 8 directions by leaping an adjacent piece.

King (=Gold Cannon+Queen) The King has a much more powerful move than the kings of most chess games. It moves diagonally and orthogonally over whole rows and is able to leap one piece, when moving. It captures diagonally and orthogonally over whole rows and is able to capture both directly and by leaping one piece.

Game transcripts

Cannon Chess game 1

Cannon Chess game 2

Cannon Chess game 3

Cannon Chess game 4

There are many interesting examples of tactics in these four games. Just to mention a few: In Cannon Chess game 1 White's move 29...Qf3-g2(GC)+ looks like a very smart move. Black defends, however, by dropping a Silver Cannon in front of his Iron Cannon, which now attacks White's King: 30. SC*e2+. After nine more checks, White is checkmate. In Cannon Chess game 2 move 7. SC*e5+ Black also defends by making a check himself. Notice the nice end, in which the White King is finally trapped by two Iron Cannons. A tactical move peculiar to Cannon Chess is demonstrated two times in Cannon Chess game 3. In move 5. CCa7-d4(B)+ the Black Copper Cannon attacks the White King by jumping over it, leaving the promotion zone and promoting to a Bishop. In move 27. SCa9-a6(R)+ the Black Silver Cannon does the same, promoting to a Rook. Cannon Chess game 4 is probably not quite as balanced as the other games. After a problematic move 10. SGf1xf7, Black's King is checked constantly during the next fifteen moves. Black is in trouble in much of the game and moves his king in 24 of the 40 moves, trying to escape White's attack. Shogi can to some extent be regarded as a race-game rather than a war game. This is true also of Cannon Shogi and Cannon Chess, but the latter can also be regarded as an advanced type of hunt-game with one or both kings being chased in all areas of the board. Cannon Chess game 4 is a good example of this. Even if Black loses the game at last, I think that he still had a chance to win, if he had started a new attack in move 38. In stead of ICe3xg3(IG), he should have chosen one of the 534 other possible moves. Perhaps one of the readers of this article is able to find a good continuation?

Here is a picture of the situation after move 37:

Zillions of games files

• Cannon Chess ZRF.
• Cannon Shogi ZRF.