Play Arrow Sudoku Online

Each marked arrow makes a Sudoku digit equal the sum of digits along its shaft. With two cells on each arrow here, you can compare the circle against two candidates immediately. A circle containing 3 requires a 1 and a 2 on its shaft. Use the usual Sudoku constraints to decide their order.

1. Read the given digits; these dark numbers stay fixed.
2. Select an empty square and use the number buttons to enter a candidate from 1 to 9.
3. Put each digit exactly once in every row and column.
4. Put each digit once in every standard three by three box.
5. The circled digit equals the sum of the two digits on its arrow shaft. Each marked arrow follows adjacent cells.
6. Use Clear to erase an editable cell. Complete the board and check the variant rules to win.
7. Each arrow has a circle and two shaft cells. The circle is the total, not another place to write the answer outside the grid. A circle of 8 may permit 1 and 7, 2 and 6, or 3 and 5; row, column and box exclusions decide which pair belongs on this particular shaft.
8. Each circled digit belongs to the grid and still participates in its row, column and box. The two marked shaft cells are adjacent along the arrow, but a separate arrow may run vertically. Work with both directions of the sum: two shaft digits determine the circle, and a known circle plus one shaft digit determines the other. Clear an entry when these demands conflict.

• Every row contains the digits 1 through 9 once.
• Every column contains the digits 1 through 9 once.
• Every standard three by three box contains 1 through 9 once.
• The circled digit equals the sum of the two digits on its arrow shaft. Each marked arrow follows adjacent cells.
• The shaft sum must match even when every row, column and box looks correct. With a fixed 2 on a shaft and a circled 7, the other shaft cell must be 5. Entering 5 may then eliminate candidates elsewhere in its column. Use the arrow as a two-way constraint between circle and shaft.

• Start with rows that have several given digits and list their missing values.
• A low circle restricts the shaft sharply. Circle 3 permits only 1 plus 2, while circle 4 permits 1 plus 3 in a straight row without repeats.
• Check columns crossing a marked constraint before placing a digit.
• When a region has just one empty cell, fill its missing value and revisit the variant clue.
• A complete standard Sudoku grid can still fail a variant rule. Review every marked constraint before the final move.

• Sudoku: Practice the standard number-placement rules before trying a variant.
• Thermo Sudoku: Compare how a related puzzle uses regions, paths or tile placement.
• Sandwich Sudoku: Compare how a related puzzle uses regions, paths or tile placement.

• Each extra constraint adds a second way to narrow candidates.
• The number pad works with touch, mouse and keyboard focus.
• The variant rules reward scanning more than one region at a time.
• Arrow Sudoku rewards arithmetic within a narrow range, but its strongest moves usually combine a sum with a standard exclusion. A low circle rules out most large shaft digits immediately. An early solved shaft can reveal a circle, which in turn resolves another row or box without trial and error.

Play Arrow Sudoku free in your browser. Start the interactive board above, use its on-screen controls and check the rules below when a deduction gets stuck. No download or account is needed.

Try another round of Arrow Sudoku on the board above. Start with the most constrained part of the grid, test each move against the stated rules, and use the reset control to try a new approach.

• Variant Sudoku reference