must move. All pieces can move one square horizontally or vertically (not diagonally). A piece may not move into its own den. Animals of either side can move into and out of any trap square. There are special rules related to the water squares: The rat is the only animal that may go onto a water square. The lion and tiger can jump over a river vertically. The lion can also jump over a river horizontally. They jump from a square on one edge of the river to the next non-water square on the other side. If that square contains an enemy piece of equal or lower rank, the lion or tiger capture it as part of their jump. A jumping move is blocked (not permitted) if a rat of either color currently occupies any of the intervening water squares. Capturing Animals capture opponent pieces by "killing/eating" them (the attacking piece the captured piece on its square; the captured piece is removed from the game). A piece can capture any enemy piece that has the same or lower rank, with the following exceptions: The rat can "kill" (capture) an elephant, but only from a land square, not from a water square. Many published versions of the game say the rat kills the elephant by "running into its ear and gnawing into its brain". A rat in the water is invulnerable to capture by any piece on land. (Therefore a rat in the water can only be killed by another rat in the water.) A piece that enters one of the opponent's trap squares is reduced in rank to 0. Thus the trapped piece may be captured by the defending side with any piece, regardless of rank. A trapped piece has its normal rank restored when it exits an opponent's trap square. Minor Variations There are some commonly played variations, as follows: The elephant may not kill the rat under any circumstances. Some play the game with the lion and tiger being equally strong, whereby they can kill each other. Some versions have the tiger outranking the lion. The leopard may jump over the river horizontally but not vertically (due to its lesser strength than the tiger or lion). It can jump over a rat in the river. All traps are universal. If an animal goes into a trap in its own region, an opponent animal is able to capture it