A simple game of tic tac toe.
this one allows for 0, 1, or 2 human players or 0, 1, or 2 computer players.
that means you can play with a friend, against the computer, or have the computer play itself.
because tic-tac-toe can only end in a tie unless one player makes a mistake, the computer player is (when 
instantiated) given a random IQ.  A computer player with a lower IQ is more likely to make a random move rather 
than a well thought-out move.  Therefore it is possible to win against the computer.