King O' Kings

The board is set up something like a plus sign. The center area is called "The Arena" and it is 4x4 grid with alternating black & white squares like a chessboard. On each side there is a 3 x 4 "Safety Zone" which serves as the starting area for each player. The safety zones are also arranged with alternating squares, although the squares are gray and the color of your pieces.
Pieces move diagonally away from their "safety zone". No piece may enter any safety zone once it has entered The Arena. The goal is to move your pieces into the arena and create kings.
Initially, all pieces are "pawns" and can move only diagonally forward (away from their safety area). Once they enter the arena, they can move diagonally in any direction but may not leave the arena.
A player may create a "prince" by landing on an opponent's pawn with one of his pawns. The stack of two pieces can then move either 1 or 2 spaces, still diagonally, but may move forwards or backwards. It may not enter any safety zone (it must remain in the arena).
A player creates a king when his prince takes a pawn or his pawn takes a prince (princes may not take each other). A king is a stack of three pieces. Once formed kings are removed to the scoring area.
The game ends when there is no possibility of additional kings being made. The winner is the player who has the most kings.
Note that while the game says it will play 2-4 there are no rules offered for any number other than 4.