Pieces rank from weakest to strongest: Rat, Cat, Dog, Wolf, Leopard, Tiger, Lion, Elephant. Stronger pieces capture weaker ones. Rats can capture elephants, but elephants cannot capture rats.
Rats can enter rivers. Lions and tigers can jump across rivers unless a rat blocks the path. Enter the enemy den to win. You cannot enter your own den.
A piece in an enemy trap loses its strength and can be captured by any opposing piece.