What is Free opening (original Reversi)?
In the free opening the board starts empty. Black places the first disc on any of the four centre squares, then White, then Black, then White, until the centre is full. These four discs flip nothing, they are the only moves allowed, and nobody can pass while the centre is being filled.
The players choose the starting position this way. If each colour ends up on a diagonal, the result is the crossed start of standard Reversi. If both discs of a colour end up side by side, the result is the parallel start, which leads to different openings and is one of the oldest starting positions of the game.
Once the four centre squares are filled, the normal rules apply: Black moves next, each move must outflank and flip at least one line of opposing discs, a player without a legal move passes, and the player with more discs at the end wins.
Rule changes
| Rule | Standard Reversi | Free opening (original Reversi) |
|---|---|---|
| Starting position | Standard ReversiTwo Black and two White discs on the four centre squares, placed crosswise. | Free opening (original Reversi)An empty board. |
| First four moves | Standard ReversiEvery move must outflank and flip at least one opposing disc. | Free opening (original Reversi)Black, White, Black and White each place one disc on an empty centre square. No other square may be played until the centre is full. |
| Flipping | Standard ReversiEvery move flips the opposing lines it outflanks. | Free opening (original Reversi)The four opening discs flip nothing. Flipping starts with the fifth disc. |
| Passing | Standard ReversiYou pass only when you have no legal move. | Free opening (original Reversi)No passing during the opening; afterwards, the same as standard. |
| After the opening | Standard ReversiBlack plays the first flipping move. | Free opening (original Reversi)Black also plays the first flipping move, from a crossed or a parallel start chosen by the players. |
History
Reversi was born in Victorian England. Two Englishmen, Lewis Waterman and John W. Mollett, each claimed in the 1880s to have invented it and accused the other of fraud. The first reliable description appeared in The Saturday Review in August 1886, and the game was sold commercially from 1888. A German publisher took it up in 1893.
The original rules did not fix the starting position. The board began empty, and each player's first two discs went on the four centre squares without flipping anything, exactly as in this variant. Each player also had only 32 discs; that limit, which is not used here, was dropped early in the 20th century, and by the 1907 Japanese World Games Rules Complete Collection the rules were almost those of today.
When Goro Hasegawa launched his version of the game in Japan in 1973, he fixed the crossed start for every game, and most players today know only that position. Some older rule sets also required the second player's second disc to flip, which the free opening here does not.