GridMewChallenge puzzles
Original puzzles, ready for a little quiet thinking.
Challenge boards include candidate-elimination reasoning such as region-line locks or common-neighbor exclusions before further forced placements appear. Labels describe the generator’s verified rule trace and remain provisional pending human calibration. Choose a board size independently.
Difficulty reflects the reasoning, not just the board size.
60 puzzles
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Make progress before placing another cat
Challenge routes include eliminations such as a region-line lock or a common-neighbor exclusion. A group can reveal where its cat cannot go even while more than one location remains. Learn to use that uncertainty as a precise candidate set.
Name the source group, list all its candidates and state the reason an outside cell is excluded. Then rescan for a single. A correct final answer does not justify an earlier unsupported guess; the walkthrough keeps the before-state of every deduction visible.
Puzzle collections by size
Learn from an original board
Explore sixty original boards with complete, diagrammed reasoning. Try a puzzle first, then use its walkthrough to check a deduction or understand a new technique. Every board passes connected-region, unique-solution and proof-replay checks.
Go to Learn · Read the validation method · Print a puzzle pack
Browse by reasoning
Choose the kind of deductions you want to practice, independently of grid size.
Original puzzle walkthroughs
Each guide has its own starting board, verified deductions and an answer you can choose to reveal.
5×5 worked puzzles
- gm-5-0001 · Two possible cats, one shared exclusion
- gm-5-0003 · Keep several possibilities alive while locks accumulate
- gm-5-0005 · Use column locks before placing the first cat
- gm-5-0012 · A column reservation unlocks a small top region
- gm-5-0014 · A forced corner is only the beginning
- gm-5-0019 · Reserve the middle of column 4 indirectly
6×6 worked puzzles
- gm-6-0002 · Two row reservations prepare a column single
- gm-6-0003 · Two singleton regions set up a vertical lock
- gm-6-0007 · A shared neighborhood settles the right edge
- gm-6-0012 · A row lock can force a cat in the same row
- gm-6-0015 · Reserve the top region before choosing its cat
- gm-6-0019 · A split column still makes a valid region lock
8×8 worked puzzles
- gm-8-0001 · Combine a reserved row with its shared neighbors
- gm-8-0002 · Let a lower row reserve the right-hand region
- gm-8-0005 · A full column reservation starts four linked locks
- gm-8-0008 · Use two row locks at different stages of the solve
- gm-8-0009 · Successive column reservations cross the upper half
- gm-8-0012 · Separate a regional reservation from a neighbor exclusion