Obtain more of your own colored pieces than your opponent at the end of the game.
Player’s are assigned a color, either white or red, based on their history of previous Reversi games on Gambit.com. If they have both had white the same number of times, then colors are assigned randomly. The white player makes the first move.
Each turn, the player places one of their own colored pieces on the board in a legal square. Legal squares are shown on the board. A legal square is one where the piece played is adjacent to an opponent's piece and that piece or a row of pieces is flanked by another piece of the player's color. All of the opponent's pieces between these two pieces are considered captured and become the color of the player who flanked them.
If the piece played flanks an opponent’s pieces in multiple directions than all of those pieces are captured.
If a player has no legal moves then his turn is skipped and the other player gets to go again.
The game is over when neither player has any legal moves remaining or the entire board is full.
The player with the most pieces of their color is declared the winner. If both players have the same number of colored pieces then the game is declared a tie.