The Jungle Game

The Jungle Game, or Dou Shou Qi, is a traditional Chinese game for children, the board and starting layout of which is illustrated below:

The basic rules of this game are:

• A piece can normally move one square in any orthogonal direction.
• Pieces capture by replacement, as in chess. However, while a piece can capture the equivalent piece of the opposing side, a piece cannot capture a piece of greater value.
• The object of the game is to move any of one's pieces into the Den square on the opponent's side of the board.
• It is not permitted to move one of one's own pieces into one's own Den square.
• A piece in one of the trap squares on the opponent's side of the board can be captured by any of the opponent's pieces, regardless of strength.

There are some exceptions to these general rules.

• Only the Mouse, the lowest-ranked piece, can occupy one of the twelve squares shown with blue wavy lines on them in the diagram, representing water squares belonging to two lakes.
• The Lion and the Tiger, ranked 6 and 7, can cross over the lakes; when adjacent to a lake in an orthogonal direction, these pieces may move in that direction, continuing that move until they reach the nearest square that is not part of the lake. This is a normal move, and it may be a capture. But these pieces may not jump over the Mouse when making this move.
• The Mouse, despite its low rank, can capture the highest-ranked piece, the Elephant.
• The Mouse cannot capture on a move from a water square to a land square.

There are some variations in the rules of this game from one account to another. Since this is a game intended for young children, the fact that some versions of the rules allow an easy way to prevent the opponent from winning does not necessarily mean that such a version of the rules cannot be correct.

One variation is exchanging the strengths of the Wolf and the Dog. This not only seems reasonable from what is known of the animals in real life, it would seem to produce a more symmetrical layout. Since most accounts do not do this, and instead it seems only to be an error in one computer implementation of the game, my inclination would simply be to rename the Dog as the Hyena to achieve plausibility.

Another variation is not allowing the Elephant to capture the Mouse. This is said to improve the game. However, from the way the initial layout of the board is set up, it seems to me that it is very unlikely that it was intended for the Mouse to be immune to capture by the Elephant.

The most critical part of the rules is what happens to a piece on one of one's own trap squares. In some accounts of the rules, these pieces are immune to capture by the enemy, because enemy pieces are weak on those squares.

This rule is the one which creates a trivial drawing strategy for the game, and, thus, it should be avoided. The two squares which are each next to two of the trap squares are already very powerful locations from which to defend one's den.

Because there are only three narrow corridors between the lakes which connect the two halves of the board, one can't send two pieces across the board side by side; if one is sending a piece to the opposite side of the board to attack, the opponent has the opportunity to bring the appropriate piece into position to counteract that piece.

This makes the Lion and the Tiger, which can jump over the lakes, very important and powerful pieces indeed.