Dominoes. Every piece once.

Every domino in the set lies somewhere in the rectangle, and each appears exactly once. Choose a number, then a neighbour, to claim the two as one piece. The same gesture again takes the join back.

Use Note a gap to mark a boundary you believe no domino crosses. It is a note to yourself: it never completes a board and costs nothing.

On a board of sums the cells are mostly bare, and the outlined regions each carry the total of the pips laid inside them. A region of one cell is simply a printed number. Choose a piece from the set, then the two cells it lies on. Lifting a piece puts it back in the set. A piece may cross a region boundary, and each half counts towards its own region.

Arrow keys move between numbers, Shift with an arrow joins in that direction, and Delete unjoins. Tab reaches all controls. The set is listed beside the board, showing which pieces are still to place.

A correctly finished rectangle earns 100 points. Joins counts the boundaries you drew and Placements the pieces you laid, corrections included; a board is measured by whichever it is played with. Your best active time is compared only on the same board. There is no countdown.

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