The rules of the game

This description is only for the sake of completeness. There is a lot of information concerning Othello available on the Web. For example see the very good introduction in tactics and strategy from Emmanuel Lazard.


Othello is a board game, played by two players ("white" and "black") on an 8x8-squared chess board. Starting at an initial position turn by turn both players place a disc on an emtpy square. According to the rules some of the discs on the board are flipped and change their color. The aim of the game is to achieve more "own" discs than the opponent.

Initial position

When the game starts, only the four central squares are occupied by discs. Usually black begins with his first move.

Legal moves

With a move one places one disc on an empty square with the own color shown on the upper side. Only those squares are allowed, which flank at least one disc of the opponent in a horizontal row, a vertical line or some diagonal. Such discs of the opponent are flipped and change their color.

For example, black has in the initial position the legal move d3, which flips the white disc on d4 since that is enclosed by the black discs on d3 and d5. The other (perfectly symmetrical) moves for black would be f5, e3 and c4.

All opponent's discs in all relevant directions are flipped. One does not have the right to choose one or more directions. A disc can be flipped more than once during the game.

In the following position white has a legal move on e2, which flips the black discs on d3, e3 and e4. In the resulting position black has exactly the moves b6, b5, b4, b3, b2, d2, d1, f2, f4, f5 and f6.

Passing and forced moves

A player having no legal moves must pass. He can (and must) move again, when he has legal moves after some answer of the opponent.

Passing while having legal moves is not allowed. In fact, this rule decides most of the games in favour of the opponent.

The end of the game

The game ends, when neither of the players has a legal move. The player owning more discs at this moment wins the game. Draw is possible, but happens rather seldom.

There are three possible situations at the end of the game:

  1. All 64 squares are occupied. The winner is the player with more discs.
  2. One of the players has no more own discs on the board. His opponent wins by 64 : 0. For example the shortest possible game of Othello ends after the moves e6 f4 e3 d6 c5 f6 e7 f5 g5 with a victory for black.
  3. Both players have own discs and there are empty squares, but neither side has legal moves. By convention the emtpies are counted as discs of the winner.

Strategy of the game

Though the final goal of the game is to gain more discs than the opponent, it is a rather poor strategy, to maximize this number in the early stages of the game.

The following is in general characteristic for a good position:

  1. A disc in a corner is stable, it cannot be flipped for the rest of the game and this corner is often used to completely dominate this side of the board. It follows, that in general it is bad to place a disc on the so called X-squares b2, b7, g2 and g7, because the opponent usually can flip this square along the long diagonal and win the corner. Similarly the C-squares a2, b1, and so on, should be used only with care.
  2. In a later stage of the game someone has to place a disc on this critical squares since these are the only legal moves. Important for a good position is therefore a high mobility, that is a great number of alternative moves.

One of the interesting features of Othello is, that this general rules do not apply in all cases. It is rather difficult to judge the critical positions and to choose the best move.

Back to main page