Bulldoku Level 400: Walkthrough & Solution
Step-by-step Bulldoku level 400 guide (5×5). One pup per color, row and column, no touching. Difficulty 43.7.
Play Level 400Step-by-step logic
1. Step: mark X in column 5
The yellow region is confined to column 5. Mark illegal cells with X.
Board after step 1 2. Step: mark X in column 5
The yellow region is confined to column 5. Mark illegal cells with X.
Board after step 2 3. 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 3 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. 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 5 6. 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 6 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. 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. Step: place pup (row 1, column 2)
After previous pups, row 1 has only one free cell — column 2. Place the cyan region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).
Board after step 9 10. Step: mark X in column 4
The pink region is confined to column 4. Mark illegal cells with X.
Board after step 10 11. Step: mark X in column 4
The pink region is confined to column 4. Mark illegal cells with X.
Board after step 11 12. 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 12 13. Step: place pup (row 5, column 3)
After previous pups, row 5 has only one free cell — column 3. Place the orange region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).
Board after step 13 14. 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 14 15. Step: place pup (row 2, column 4)
After previous pups, row 2 has only one free cell — column 4. Place the pink region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).
Board after step 15 16. Step: place pup (row 3, column 1)
After previous pups, row 3 has only one free cell — column 1. Place the mint region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).
Board after step 16 17. Step: place pup (row 4, column 5)
After previous pups, row 4 has only one free cell — column 5. Place the yellow region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).
Board after step 17
Final solution
All pups placed correctly: R1 C2, R2 C4, R3 C1, R4 C5, R5 C3
Similar difficulty levels
FAQ
- How do I solve Bulldoku level 400?
- Follow the 17 steps above: find forced placements first, then mark impossible cells with X.
- Where can I play level 400 online?
- Click "Play Level 400" to open the free browser game with this exact board.