This post contains a visual warm-up (no writing should be necessary) for Kropki Pairs in Just One Cell form.

PDF

or solve online in Penpa, or also solve online in SudokuPad as a new option (note: highly recommended to turn off “Mark Solved Digits” option if you use that in SudokuPad).

Author/Opus: This is the 4th puzzle from guest contributor Clover.

Rules: This Sudoku does not have a unique solution for the full grid (it actually has a large number of solutions), but there is exactly one cell in which a number can be logically placed that is fixed across all solutions. Find this cell and its unique value.

This puzzle follows Kropki Pairs Sudoku rules, so no number repeats in any row, column, or bold region. If a white circle is given between two adjacent cells, then the two numbers in those cells must differ by 1. If a black circle is given between two adjacent cells, then the two numbers must have a ratio of 2. Pairs of cells without circles can have any relationship.

Time Standards: This competition had 1-point (easy), 2-point (medium), 3-point (hard), or higher value puzzles. This would have been worth 0.5 points (very easy category), roughly less than .5 minute target.

Solution: PDF

Note: Follow this link for other Just One Cell Sudoku.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Just One Cell Sudoku Discussion post on the GMPuzzles Discord. Not a member of the Discord? Click this link for basic access.

This is the second of two puzzles posting today in this style, both of similar difficulty.

PDF

or solve online in Penpa, or also solve online in SudokuPad as a new option (note: highly recommended to turn off “Mark Solved Digits” option if you use that in SudokuPad).

Author/Opus: This is the 572nd puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: This Sudoku does not have a unique solution for the full grid (it actually has a large number of solutions), but there is exactly one cell in which a number can be logically placed that is fixed across all solutions. Find this cell and its unique value.

This puzzle follows Thermo-Sudoku rules, so no number repeats in any row, column, or bold region. Some thermometer shapes are in the grid; numbers must be strictly increasing from the round bulb to the flat end.

Time Standards: This competition had 1-point (easy), 2-point (medium), 3-point (hard), or higher value puzzles. This was worth 2 points (medium category), roughly 1.5-2 minute target.

Solution: PDF

Note: Follow this link for other Just One Cell Sudoku.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Just One Cell Sudoku Discussion post on the GMPuzzles Discord. Not a member of the Discord? Click this link for basic access.

This is the first of two puzzles posting today in this style, both of similar difficulty.

PDF

or solve online in Penpa, or also solve online in SudokuPad as a new option (note: highly recommended to turn off “Mark Solved Digits” option if you use that in SudokuPad).

Author/Opus: This is the 571st puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: This Sudoku does not have a unique solution for the full grid (it actually has a large number of solutions), but there is exactly one cell in which a number can be logically placed that is fixed across all solutions. Find this cell and its unique value.

This puzzle follows Thermo-Sudoku rules, so no number repeats in any row, column, or bold region. Some thermometer shapes are in the grid; numbers must be strictly increasing from the round bulb to the flat end.

Time Standards: This competition had 1-point (easy), 2-point (medium), 3-point (hard), or higher value puzzles. This was worth 2 points (medium category), roughly 1.5-2 minute target.

Solution: PDF

Note: Follow this link for other Just One Cell Sudoku.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Just One Cell Sudoku Discussion post on the GMPuzzles Discord. Not a member of the Discord? Click this link for basic access.

This is the second of two puzzles posting today in this style, and is likely the harder of the pair.

PDF

or solve online in Penpa, or also solve online in SudokuPad as a new option (note: highly recommended to turn off “Mark Solved Digits” option if you use that in SudokuPad).

Author/Opus: This is the 570th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: This Sudoku does not have a unique solution for the full grid (it actually has a large number of solutions), but there is exactly one cell in which a number can be logically placed that is fixed across all solutions. Find this cell and its unique value.

This puzzle follows Even/Odd Sudoku rules, so no number repeats in any row, column, or bold region. Cells with a square must contain an even number; cells with a circle must contain an odd number.

Time Standards: This competition had 1-point (easy), 2-point (medium), 3-point (hard), or higher value puzzles. This was worth 3 points (hard category), roughly 2.5-3 minute target.

Solution: PDF

Note: Follow this link for other Just One Cell Sudoku.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Just One Cell Sudoku Discussion post on the GMPuzzles Discord. Not a member of the Discord? Click this link for basic access.

This is the first of two puzzles posting today in this style, and is likely the easier of the pair.

PDF

or solve online in Penpa, or also solve online in SudokuPad as a new option (note: highly recommended to turn off “Mark Solved Digits” option if you use that in SudokuPad).

Author/Opus: This is the 3rd puzzle from guest contributor Clover.

Rules: This Sudoku does not have a unique solution for the full grid (it actually has a large number of solutions), but there is exactly one cell in which a number can be logically placed that is fixed across all solutions. Find this cell and its unique value.

This puzzle follows Even/Odd Sudoku rules, so no number repeats in any row, column, or bold region. Cells with a square must contain an even number; cells with a circle must contain an odd number.

Time Standards: This competition had 1-point (easy), 2-point (medium), 3-point (hard), or higher value puzzles. This was worth 1 point (easy category), roughly .75-1 minute target.

Solution: PDF

Note: Follow this link for other Just One Cell Sudoku.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Just One Cell Sudoku Discussion post on the GMPuzzles Discord. Not a member of the Discord? Click this link for basic access.

Today is Grant Fikes’ 38th birthday, and he has created this Numberlink as a gift to share as a special challenge before today’s other posts.

As a second gift, Grant wants to share six subscriptions to his Outside the Fox Puzzles (a mainly word puzzles series but with one logic puzzle per week as well). Send a picture / screenshot of the completed puzzle to hiddencontest@gmpuzzles.com before 9 AM PT May 28 (Wednesday) to be entered in a random drawing to win a subscription. Contest is now closed and winners being notified.

(view directly for a larger image)

PDF

or solve online (using our beta test of Penpa-Edit tools in linex mode where left click+drag draws lines and right click marks X’s)

Theme: 38 Years

Author/Opus: This is the 506th puzzle from our contributing puzzlemaster Grant Fikes.

Rules: Connect each pair of identical numbers with a path passing through edge-adjacent cells. No cell may be used on more than one path.

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 6:30, Master = 10:00, Expert = 20:00

Solution: PDF and solving animation of possible path.

Note: Follow this link for other Numberlink puzzles and this link for other Loop/Path puzzles.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our General Blog Puzzle Discussion post on the GMPuzzles Discord. Not a member of the Discord? Click this link for basic access and check subscriber instructions for role-related access.

This is the second of two puzzles posting today in this style.

PDF

or solve online in Penpa, or also solve online in SudokuPad as a new option (note: highly recommended to turn off “Mark Solved Digits” option if you use that in SudokuPad).

Author/Opus: This is the 1st puzzle from guest contributor Gliperal.

Rules: This Sudoku does not have a unique solution for the full grid (it actually has a large number of solutions), but there is exactly one cell in which a number can be logically placed that is fixed across all solutions. Find this cell and its unique value.

This puzzle follows Classic Sudoku rules, so no number repeats in any row, column, or bold region.

Time Standards (highlight to view): This competition had 1-point (easy), 2-point (medium), 3-point (hard), or higher value puzzles. This was worth 5 points (extreme category), roughly 5+ minute target.

Solution: PDF

Note: Follow this link for other Just One Cell Sudoku.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Just One Cell Sudoku Discussion post on the GMPuzzles Discord. Not a member of the Discord? Click this link for basic access.

This is the first of two puzzles posting today in this style.

PDF

or solve online in Penpa, or also solve online in SudokuPad as a new option (note: highly recommended to turn off “Mark Solved Digits” option if you use that in SudokuPad).

Author/Opus: This is the 569th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: This Sudoku does not have a unique solution for the full grid (it actually has a large number of solutions), but there is exactly one cell in which a number can be logically placed that is fixed across all solutions. Find this cell and its unique value.

This puzzle follows Classic Sudoku rules, so no number repeats in any row, column, or bold region.

Time Standards (highlight to view): This competition had 1-point (easy), 2-point (medium), 3-point (hard), or higher value puzzles. This was worth 3 points (hard category), roughly 2.5-3 minute target.

Solution: PDF

Note: Follow this link for other Just One Cell Sudoku.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Just One Cell Sudoku Discussion post on the GMPuzzles Discord. Not a member of the Discord? Click this link for basic access.

This is the second of two puzzles posting today in this style.

PDF

or solve online in Penpa, or also solve online in SudokuPad as a new option (note: highly recommended to turn off “Mark Solved Digits” option if you use that in SudokuPad).

Author/Opus: This is the 568th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: This Sudoku does not have a unique solution for the full grid (it actually has a large number of solutions), but there is exactly one cell in which a number can be logically placed that is fixed across all solutions. Find this cell and its unique value.

This puzzle follows Classic Sudoku rules, so no number repeats in any row, column, or bold region.

Time Standards (highlight to view): This competition had 1-point (easy), 2-point (medium), 3-point (hard), or higher value puzzles. This was worth 3 points (hard category), roughly 2.5-3 minute target.

Solution: PDF

Note: Follow this link for other Just One Cell Sudoku.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Just One Cell Sudoku Discussion post on the GMPuzzles Discord. Not a member of the Discord? Click this link for basic access.

This is the first of two puzzles posting today in this style.

PDF

or solve online in Penpa, or also solve online in SudokuPad as a new option (note: highly recommended to turn off “Mark Solved Digits” option if you use that in SudokuPad).

Author/Opus: This is the 2nd puzzle from guest contributor Clover.

Rules: This Sudoku does not have a unique solution for the full grid (it actually has a large number of solutions), but there is exactly one cell in which a number can be logically placed that is fixed across all solutions. Find this cell and its unique value.

This puzzle follows Classic Sudoku rules, so no number repeats in any row, column, or bold region.

Time Standards: This competition had 1-point (easy), 2-point (medium), 3-point (hard), or higher value puzzles. This was worth 2 points (medium category), roughly 1.5-2 minute target.

Solution: PDF

Note: Follow this link for other Just One Cell Sudoku.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Just One Cell Sudoku Discussion post on the GMPuzzles Discord. Not a member of the Discord? Click this link for basic access.