how to play...
Reversi is a game for two persons. You can play against your computer in two different levels. The easy mode lets the computer search for it´s best move, in the hard mode the computer searches for is´s best move with the consequences of your move.
    Aim of the game is to get more stones of your kind than your opponent. Both players move one after another. If it´s your turn, you have to place an own stone on an empty field next to an opponent´s stone so that this stone or a row of stones is between your stones. This is possible in three directions: straight, cross and horizontal. Your opponent loses in this way surrounded stones, this are now your stones. The game is over if no one can place a stone.
You are not able to loose these stones in the corner. So, try to place a stone in a corner and then next to them. Then it will be easy to win.

Have fun.