Reversi
Either of the two opening positions shown here may occur in Reversi, as well as rotations and reflections of them. Players are only required to alternate placing counters in the four central squares on the first four moves and any configuration my result. The (nearly) identical game of Othello, however, requires that the colors crisscross, thus only the configuration on the left and its reflection is allowed as an opening position.
Alternate Names
Identical or similar games have gone under the names of Reversi, Othello as marketed by Mattel, Exit, Chain Reaction, and Ataxx (an arcade/computer version).
No. of Players
Two
Equipment
An 8x8 square grid and 64 identical, reversible counters are required for play. The counters, typically called disks or discs, are light on one side and dark on the other.
History
Objective
Play
Nor is it concerned about Reversi, which is again popular and widely played, after a version of it was brought out commercially under another trademark, although I will now mention a few words about it here.
The game was originally played on a board of a different shape, and was available to the public in that form in 1876, as invented by John W. Mollett, under the name "The Game of Annexation". I have seen the shape of the board for that game in three diagrams people have drawn for their web sites, but I have not been able to locate a more original source for that information:
No doubt the board was printed in black-and-white, but it could well have been chequered in some way, as would have been common at that time.
Although I have not been able to find a contemporary account of the shape of its board, the legal case brought by John W. Mollett against Lewis Waterman is recorded in contemporary accounts (such as "The Law Times Reports of Cases Decided in the House of Lords, the Privy Council, the Court of Appeal..." volume LIX, for September 1888 to February 1889, available on Google Books), and so there is no doubt about the original provenance of the game.
However, the firm of F. H. Ayres, still billing Mollett as the inventor, later sold sets for the game of Annexation that used the same 8 by 8 layout as those sold by Lewis Waterman's firm Jacques & Co., which we will meet again on this page as selling Shan Tu, a variation of Chinese Checkers, and which is well known as having first sold Chess pieces on the Staunton pattern.
The modern game, played on a board with the same shape as a Chess or Checkers board, was invented in 1883 by Lewis Waterman. However, it still differed in two respects from the game currently sold as Othello, invented by Goro Hasegawa: in Reversi, players begin by alternately placing pieces in the four central squares of the board, rather than automatically starting from the fixed configuration which is the recommended one for Reversi, and, in Reversi, if a player cannot place a piece so as to flip some of the opponent's pieces in a turn, that player merely forfeits his turn, not the game.
Although Othello began being sold commercially in 1973, Goro Hasegawa invented this version of Reversi shortly after the end of the Second World War; this was before the game of Reversi was brought to public awareness in Martin Gardner's Mathematical Games column for July, 1961, so it indeed was an independent invention.
Later, a more elaborate version of Reversi was brought out, where the pieces were cubes having six different colors on their six sides, so that it could be played by up to six players, under the name "Royal Reversi", the board being pictured at left.
In this version of the game, one piece is rolled as a die to decide who the first player will be, and then it is placed with the same side uppermost on the central circle. Then, the players, starting with that first player and proceeding counter-clockwise, place pieces with their color uppermost on the numbered circles until each has placed two pieces, in the order indicated by the numbers:
10 2 1 7 11 3 -- 4 12 8 5 6 9
There was one very important way in which the rules for Royal Reversi differed from those for ordinary Reversi. In order to move, a player must be able to place a piece with his color uppermost so that there is a line of pieces of other colors, terminated by another piece with his color uppermost, to be flipped - or, in this case, rotated, to be his color. This is still true; what differs is that if such a move creates several such lines of pieces that can be turned, it is only required that the player making the move flip the pieces in at least one of those lines; flipping the pieces in any other line formed by the move is optional (although one can only flip all the pieces in a line, or leave them all untouched).
The 1947 edition of Richard L. Frey's The New Complete Hoyle notes that Royal Reversi was revived by Milton-Bradley in 1938 under the name Chameleon; this was later noted in Martin Gardner's column as well. However, Martin Gardner correctly noted that Chameleon was not quite identical to Royal Reversi: in fact, its board looked like this:
Although the central squares are numbered, somewhat as in Royal Reversi, the square in the center is not skipped, but is instead square number 7, the numbers running from 1 to 13, so the rules for the initial placement of the first few pieces would have to be at least slightly different from those for Royal Reversi to accommodate this, such as placing the first piece on square 7, and then the others in numerical order skipping number 7.
The board, instead of simply being a flat printed surface, had square holes in which the cubes rested.
There is also a game, published by Dujardin, named "Royal Reversi", which uses disks that have two different colors on their two sides, as in Reversi or Othello, and which come in several different pairs of colors; these disks are placed on an 8 by 8 board on which the squares bear images of playing cards.
