Game Rules

The game of Reversi was invented in London, in the last half of the 19th century. The game is played by two players: a red player and a green player. The players place counters of their respective colors alternately. Red plays first. Each counter must be placed such that it 'closes-in' a straight line of one or more of the opponent's counters (horizontal, vertical or diagonal) . All counters closed-in by the just placed counter then change color.

If it is not possible for a player to close in at least one of the opponents counters, he passes and his opponent can play.The game ends if the board is filled with 64 counters, or if none of the players can do a move. The player with the most counters of his color wins the game.

To help you play the game, the empty fields were you can play are marked with a number. The number indicates the number of counters changing sides with that move.


The java applet above allows you to play the game. It shows the board. It starts in a situation where red, the user is the first player, and green, the computer, moves second. You can change this by pressing new game: A window pops up where you can choose between several altenatives:

There is another button undo move in the applet. You can press this button to undo the last move. Note that you typically must press this button twice, because to change your move you must undo the computers move first, and then your move.

There are two status lines. One indicates whose turn it is, and how many counters each player has. The other one tells you if the computer is thinking.


We encourage you to download the sourcecode. Here are a few reasons to do so.
[click here if you see no menu]