Bulldoku Level 678: Walkthrough & Solution

Step-by-step Bulldoku level 678 guide (6×6). One pup per color, row and column, no touching. Difficulty 58.0.

Play Level 678

Step-by-step logic

  1. 1. Step: mark X in row 1

    The cyan region is confined to row 1. Mark X on cells in that row that belong to other regions.

    Board after step 1
  2. 2. Step: mark X in row 1

    The cyan region is confined to row 1. Mark X on cells in that row that belong to other regions.

    Board after step 2
  3. 3. Step: mark X in row 1

    The cyan region is confined to row 1. Mark X on cells in that row that belong to other regions.

    Board after step 3
  4. 4. Step: mark X (line reservation)

    Several regions share the same rows or columns — other cells on those lines are impossible. Mark them with X.

    Board after step 4
  5. 5. Step: mark X (line reservation)

    Several regions share the same rows or columns — other cells on those lines are impossible. Mark them with X.

    Board after step 5
  6. 6. Step: logical elimination

    Placing a pup on the trial cell would leave a region with no legal move. Mark that cell with X.

    Board after step 6
  7. 7. Step: logical elimination

    Placing a pup on the trial cell would leave a region with no legal move. Mark that cell with X.

    Board after step 7
  8. 8. Step: logical elimination

    Placing a pup on the trial cell would leave a region with no legal move. Mark that cell with X.

    Board after step 8
  9. 9. Step: mark X (line reservation)

    Several regions share the same rows or columns — other cells on those lines are impossible. Mark them with X.

    Board after step 9
  10. 10. Step: logical elimination

    Placing a pup on the trial cell would leave a region with no legal move. Mark that cell with X.

    Board after step 10
  11. 11. Step: logical elimination

    Placing a pup on the trial cell would leave a region with no legal move. Mark that cell with X.

    Board after step 11
  12. 12. Step: mark X (line reservation)

    Several regions share the same rows or columns — other cells on those lines are impossible. Mark them with X.

    Board after step 12
  13. 13. Step: mark X (line reservation)

    Several regions share the same rows or columns — other cells on those lines are impossible. Mark them with X.

    Board after step 13
  14. 14. Step: mark X (line reservation)

    Several regions share the same rows or columns — other cells on those lines are impossible. Mark them with X.

    Board after step 14
  15. 15. Step: mark X (line reservation)

    Several regions share the same rows or columns — other cells on those lines are impossible. Mark them with X.

    Board after step 15
  16. 16. Step: mark X (line reservation)

    Several regions share the same rows or columns — other cells on those lines are impossible. Mark them with X.

    Board after step 16
  17. 17. Step: mark X (line reservation)

    Several regions share the same rows or columns — other cells on those lines are impossible. Mark them with X.

    Board after step 17
  18. 18. Step: logical elimination

    Placing a pup on the trial cell would leave a region with no legal move. Mark that cell with X.

    Board after step 18
  19. 19. Step: logical elimination

    Placing a pup on the trial cell would leave a region with no legal move. Mark that cell with X.

    Board after step 19
  20. 20. Step: place pup (row 2, column 1)

    After previous pups, column 1 has only one free cell — row 2. Place the pink region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).

    Board after step 20
  21. 21. Step: logical elimination

    Placing a pup on the trial cell would leave a region with no legal move. Mark that cell with X.

    Board after step 21
  22. 22. Step: place pup (row 6, column 2)

    After previous pups, column 2 has only one free cell — row 6. Place the lavender region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).

    Board after step 22
  23. 23. Step: place pup (row 4, column 3)

    After previous pups, column 3 has only one free cell — row 4. Place the yellow region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).

    Board after step 23
  24. 24. Step: place pup (row 1, column 4)

    After previous pups, column 4 has only one free cell — row 1. Place the cyan region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).

    Board after step 24
  25. 25. Step: place pup (row 5, column 6)

    After previous pups, row 5 has only one free cell — column 6. Place the orange region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).

    Board after step 25
  26. 26. Step: place pup (row 3, column 5)

    After previous pups, row 3 has only one free cell — column 5. Place the mint region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).

    Board after step 26

Final solution

All pups placed correctly: R1 C4, R2 C1, R3 C5, R4 C3, R5 C6, R6 C2

Solved board

Similar difficulty levels

FAQ

How do I solve Bulldoku level 678?
Follow the 26 steps above: find forced placements first, then mark impossible cells with X.
Where can I play level 678 online?
Click "Play Level 678" to open the free browser game with this exact board.