The game of Checkers (known as Draughts in Britain) is a traditional game that is more popular for casual play than Chess in the English-speaking world.
Only the dark squares of the board are used. A checker can be moved one square diagonally forwards, and it can also jump over one or more of the opponent's men, capturing them in doing so. As long as a capturing move is possible, one must be made: that is, if more than one capturing move is available, any capturing move can be chosen, but whichever sequence of multiple captures is chosen, it must be followed to completion.
When a checker (or man) reaches the opponent's back rank, it promotes to a king. A king has the additional power of moving and jumping backwards in addition to forwards.
The rule that capture, when possible, is compulsory was added to Checkers in France at some time around the year 1535; the game with this rule was called the Jeu Forcé, while the older game without that rule was known, in contrast, as the Jeu Plaisante.
To make diagrams of checker positions easier to read, by convention the light and dark coloring of the squares is reversed in such a diagram. Also, the squares of the board are numbered to facilitate the recording of moves in a game; this numbering is shown in the diagram at left.
The possible first moves for the dark pieces are, therefore, noted as 9-13, 9-14, 10-14, 10-15, 11-15, 11-16, and 12-16. The usually preferred move is 11-15. The possible moves for the light pieces, the player with them moving second, are independent of the first move of the dark pieces, and are 21-17, 22-17, 22-18, 23-18, 23-19, 24-19, and 24-20.
Although 11-15 is the preferred initial move, the others are also playable, and, thus, they are given names as openings:
9-13 Edinburgh 9-14 Double Corner 10-14 Denny 10-15 Kelso 11-15 Old Faithful 11-16 Bristol 12-16 Dundee