Reversi rules

Reversi

Reversi turns a quiet corner of the board into a sudden swing of colour. Two players share an eight-by-eight grid and try to finish with more discs showing their colour.

Starting position

The four centre squares hold two discs of each colour in a diagonal pattern. Black moves first. Players then alternate, placing one disc on an empty square whenever they have a legal move.

Flanking and flipping

Your new disc must trap at least one uninterrupted line of opposing discs between itself and another of your discs. Lines may run horizontally, vertically or diagonally. Flip every opposing disc trapped by your move, in every direction that qualifies. You cannot place a disc where nothing would flip, and you cannot skip an opposing disc or cross an empty square to complete a line.

For example, if a row reads your disc, two opposing discs, then an empty square, placing your disc in that empty square flips both discs in between. The same move might also flip along a diagonal. Discs remain on their squares for the rest of the game, although their colour can change many times.

Passing and winning

If you have no legal placement, your turn passes. If your opponent can move, play continues even when the board is not full. The game ends when neither player can move. Count the discs then: the player with more wins, and equal counts are a draw. A corner disc can never be flipped, so corners are especially valuable even though every legal move follows the same simple rule.