What is Arrow Sudoku?
Arrow Sudoku is a Sudoku variant where arrows originating from circled cells are overlaid on the grid. Just like in the example below.
In addition to the standard Sudoku rules, in Arrow Sudoku the digits in the circled cells must be the sum of the digits along the arrow point out of it.
So, for example, if we consider the circle in the very center of the grid, you’ll notice that the cells its arrow covers all have their digits given. In this case it’s a 7 and 2. This means the center cell must be a 9.
Unlike Thermo Sudoku, it does not matter what order the digits along the arrows are in. The only additional rule is that they must sum to the digit in the circled cell.
Arrow Sudoku rules
In addition to the standard Sudoku rules of every row, column, and 3×3 region containing the numbers 1 to 9 once and only once each, Arrow Sudoku only has one additional rule.
That is simply wherever there is an arrow, the digits along the shaft of the arrow must sum to the number at the base of the arrow (in the circled cell). These digits along the shaft can appear in any order and can contain repeated digits as long as the standard rules of Sudoku aren’t broken.
Can the same circled cell have multiple arrows?
In most Arrow Sudoku puzzles each circled cell will only have a single arrow originating from it. However, there is nothing stopping there being multiple arrows coming out of the same cell.
If this is the case, the digits along both the arrows will need to sum to the digit in the base of the arrow. Just like in the example below.
Where to play
Along with the example at the top of this page, you can find Arrow Sudoku puzzles to solve at the following places: