Othello is a game played on a board with 64 squares, using dual-sided round pieces, one side black, the other white. The game starts with 4 pieces placed in the center of the board as shown.
Players take turns placing a piece of their color in order to capture one or more of their opponents pieces between the new piece and one of their existing pieces, in a straight line. Any captured pieces are flipped over to become the player's pieces. A player may capture pieces in more than one direction.
Figure 13: Evolution of a Move
If no move exists where the current player may capture a piece, then the player forfeits the move. The game ends when neither player has a valid move, often this is when the board is completely filled. The winner is the player with the most pieces.