Numbridge is a game for two on a sudoku field. The cells are hexagons laid out in a rhombus. The rule is the same as on paper: every digit appears exactly once in each row, each column and each block.
- A row runs horizontally, while a column slants down and to the right: the rows of the rhombus are shifted by half a cell.
- A cell has six neighbours: left, right, two above and two below. There are no corner neighbours as on a square board.
- Givens are the cells open from the start. They belong to nobody and help you solve.
A correctly named digit closes a cell, and the cell becomes yours. You never solve the whole sudoku: over a game each player closes only part of the cells.