For the first iteration of our project we are working on playing verbal tic tac toe with our robot.  Our basic approach is to have the robot keep track of a 2D-Array which will function as the playing board.  The board will be referenced as boxes 0-8 and will initially be filled with all dashes.  When it is the user's turn, they specify the number box that they want and the robot will place an 'X' in it.  During the robot's turn it scans the board for dashes and places an 'O' when one is found.  If there are no dashes the robot analyzes the board to see who won.