The playing field can be thought of as a diagonally crossed square with one side removed. Movement is along the lines as show in the figure. (At the risk of pointing out the obvious, the playable locations are the four corners of the square and the center.)
|Pong Hau K'i|
Players move their pieces alternately to the empty point until one player cannot move. The player that cannot move loses.
An alternate way to start that is mentioned by R.C. Bell is that the players alternate placing their pieces onto the field before starting to move.