古式リバーシ

The 1880s rule: the players lay the first four discs themselves. Any flipping game here can be set up either way.

The English parlour game before the fixed opening: the centre four were placed by the players, in turn, so two openings were possible.

目的

Finish with more discs than the other colour.
The game ends when neither colour has a legal move — usually a full board. Equal counts are a draw.

The board starts empty. The first four discs are laid in the centre four squares, one a turn, turning nothing.
The set-up lets a game start the other way: centre discs placed, or laid by the players.
A disc goes only where it brackets one or more of the other colour in a straight run — any direction — with one of your own at the far end. Every bracketed run turns to your colour.
A colour with nowhere to go passes, and the other colour plays again. You may not pass while you have a move.
When neither colour can move, the discs are counted.

Either colour may open, or the first stone may be drawn by lot.
The threat reading, hints and the chance-of-winning bar are switched off: there are no lines to read here, only discs to count.
8×8. Laying the centre yourself allows the parallel opening the fixed rule rules out.