Reversi

Reversi, commercially known as Othello since the 1970s, is a game of placement and capture. The game starts with four pieces in the centre of the board, two of each colour. Players place pieces one at a time, capturing rows of opposing pieces that are sandwiched between the newly-placed piece and other friendly pieces around the board. Pieces are black on one side and white on another; a captured black piece is turned over to show its white side.

History of Reversi

The game of Reversi was patented in 1888, though it strongly resembles an earlier game of 1870, Annexation, on which it was probably based. This product of the Victorian board game boom remained popular until World War I, after which it was largely forgotten.

In 1968 the game was reinvented in Japan, as Othello. Since then it has gained immense popularity, at first in Japan. More recently it has been a popular subject for programmers of computers and mobile phones, spreading its popularity across the world.

Rules for Reversi

1. Reversi is played on a board split into 8 rows of 8 squares. A chess board may be used, but a non-chequered board is preferable, as the chequered pattern can be distracting.

2. There are 64 pieces, each of which is coloured white on one side and black on the other, allowing a piece to change colour during play.

3. Two players take part, one being referred to as white and the other as black. The white player takes the first turn. Placing Pieces

4. In the initial phase of the game, the four central squares must be filled. White places a piece in one of them, white face upwards. Black places a piece in another of them, black face upwards.

5. White and black then place two further pieces in the remaining central squares in the same manner. Play then passes to the main phase, white taking the first turn.

6. In his turn a player places a single piece, with his own colour face upwards.

7. A piece must be placed so that it and a comrade enclose a line of one or more pieces of the opponent. A line of enclosed pieces may run horizontally, vertically or diagonally.

8. The enclosed pieces are then captured, by turning them over to show the player's own colour.

9. It is possible to enclose two or more lines of enemy pieces simultaneously; all of the enclosed pieces are turned over.

10. If a player cannot legally place a piece, he misses his turn. Ending the Game

11. The game is over when neither player can place a piece. Typically this happens when: (i). the board is full; or (ii). the pieces are all of one colour, so neither player can enclose his opponent.

12. The winner is the player who has the most pieces showing his colour at the end of the game. Draws are possible, but unlikely.

Variations: It is possible to play reversi on a 6×6 board with 36 pieces, or a 10×10 board with 100.

Strategy in Reversi

The first lesson for a novice to learn is that aiming to capture the greatest number of pieces on each turn is not a successful strategy. It may work against another beginner who is trying to do the same, but there are deeper subtleties to the game.

Not all squares on the board are equal; each have their strengths and weaknesses. The corner squares are most obvious as the strongest squares, as they cannot be captured once held. The squares adjacent to them are consequently dangerous, as a piece placed here may offer the opponent an opportunity to take the corner; diagonally adjacent squares are the worst.

Other squares around the edge are relatively strong, as they can only be taken when the opponent places pieces of their own at the edge. Surprisingly, the squares around the middle are quite valuable. While easily taken, a play to these squares is reasonably safe; a loss here can often be retaken later on, in contrast to edge squares which are more stable.

The two main strategies in the game are to gain territory and secure the strongest squares. It is best to concentrate on gaining the strong squares early on, as territory gained in the early phases of the game is easily taken away. Once the strong squares are secured, these may be used to gain territory; the gaining of territory is most important later in the game.

Tactics involve securing the corners while not letting the enemy do the same, avoiding the weakest squares beside the corner unless it is absolutely safe to take them. It is also important to eliminate enemy pieces that lie inside the mass of your own forces, as they are extremely dangerous if left to capture from within.