GridMew1Check row 2
row 2 has only one remaining candidate: row 2, column 1. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 1. Place one cat, then exclude 4 other cells.Clear the upper-left before revisiting row 4
Original puzzle gm-6-0013
By GridMew · Published 15 October 2026 · Updated 16 October 2026
6 × 6 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.
The given at r3c3 fills C, while r6c6 fills F. Row 2 is left with r2c1. Its long column effect is useful, but the next single appears in row 4 rather than immediately above it.
6×6 · 2 fixed cats · 4 explained deductions. Region sizes: A: 6 · B: 6 · C: 8 · D: 2 · E: 7 · F: 7.
A deduction worth checking
r4c5 removes r1c5 through column 5. The top row then settles at r1c4; the final row-5 cat is checked after that.
A move to double-check · r1c5
A cell three rows away can still compete for the same column. Do not limit the update from r4c5 to its visible neighbors.
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.
B B A A A A B B C C C A B B C C C A E E C D D F E E C F F F E E E F F F
Fixed cats: row 3, column 3; row 6, column 6. One cat is required in each row, column and region.
Step-by-step walkthrough
2Check row 4
row 4 has only one remaining candidate: row 4, column 5. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 2. Place one cat, then exclude 1 other cells.3Check row 1
row 1 has only one remaining candidate: row 1, column 4. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 3. Place one cat, then exclude 0 other cells.4Check row 5
row 5 has only one remaining candidate: row 5, column 2. 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.Show solution · reveals all cat positions
The final cats satisfy every row, column and region quota, with no edge or corner contact.
Cat positions: r1c4, r2c1, r3c3, r4c5, r5c2, r6c6.
Try another puzzle
A bottom-right cat clears a path through row 3
gm-6-0005 · 6×6 · intro
Practice single-candidate placements on another 6×6 board.
Read this walkthrough →Let the fourth row settle the top edge
gm-5-0002 · 5×5 · intro
Transfer single-candidate placements to a 5×5 grid; compare how the candidates change.
Read this walkthrough →A shared neighborhood settles the right edge
gm-6-0007 · 6×6 · challenge
Compare this route with shared-neighbor exclusions, and check why that different rule is needed.
Read this walkthrough →