Players take turns selecting any of the available pieces. Once a piece is selected, the player gives the piece to his/her opponent who plays it in any of the available positions on the board.
The winning player is the first player to create a row or diagonal which contains any four pieces that share a common attribute. (ie: 4 dark pieces or 4 short pieces, 4 round pieces, etc).
The winning player need not have played all four of the winning pieces. He/she need only to place the final piece. Sounds easy? Good luck!