GridMew1Check region D
region D has only one remaining candidate: row 4, column 7. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 1. Place one cat, then exclude 6 other cells.A narrow middle region sets the upper rows free
Original puzzle gm-8-0013
By GridMew · Published 15 October 2026 · Updated 16 October 2026
8 × 8 intro
Read the starting position, follow the deductions, and check the move that is easy to misread.
Puzzle board · starting state
How to approach this board
Coordinates such as r2c3 mean row 2, column 3. Count rows from the top and columns from the left.
Three givens fill A, B and E. Region D’s row-4 band then has only r4c7 left. Use its column and neighborhood effects to narrow C before working through the lower-left area.
8×8 · 3 fixed cats · 5 explained deductions. Region sizes: A: 3 · B: 10 · C: 11 · D: 4 · E: 2 · F: 7 · G: 13 · H: 14.
A deduction worth checking
C resolves at r3c4. That cat removes the distant r7c4 and r8c4, which helps H resolve lower down.
A move to double-check · r8c4
The lower H cell r8c4 cannot coexist with r3c4. Their shared column matters even though a large visual gap separates them.
Green marks the cell being discussed, not a cat to place. This is the position before step 2; compare the deduction below.
Read the starting board as text
Each line is one row, left to right. Matching letters belong to the same connected region.
A A A C C B B B C C C C C B B B H H C C C C B B H H H D D D D B F H H H E G G B F F F H E G G G F F H H G G G G F H H H G G G G
Fixed cats: row 5, column 5; row 1, column 3; row 2, column 8. One cat is required in each row, column and region.
Step-by-step walkthrough
2Check region C
region C has only one remaining candidate: row 3, column 4. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 2. Place one cat, then exclude 4 other cells.3Check region H
region H has only one remaining candidate: row 8, column 2. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 3. Place one cat, then exclude 5 other cells.4Check row 6
row 6 has only one remaining candidate: row 6, column 1. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 4. Place one cat, then exclude 0 other cells.5Check row 7
row 7 has only one remaining candidate: row 7, column 6. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 5. Place one cat, then exclude 0 other cells.Show solution · reveals all cat positions
The final cats satisfy every row, column and region quota, with no edge or corner contact.
Cat positions: r1c3, r2c8, r3c4, r4c7, r5c5, r6c1, r7c6, r8c2.
Try another puzzle
Read the lower singles before returning to the top
gm-8-0006 · 8×8 · intro
Practice single-candidate placements on another 8×8 board.
Read this walkthrough →Use the three completed upper rows as constraints
gm-6-0004 · 6×6 · intro
Transfer single-candidate placements to a 6×6 grid; compare how the candidates change.
Read this walkthrough →Let a lower row reserve the right-hand region
gm-8-0002 · 8×8 · challenge
Compare this route with candidate locks, and check why that different rule is needed.
Read this walkthrough →