See more discussion of the puzzles from the United States’ 2021 Puzzle Grand Prix on this post. Note there are some construction details and potential spoilers on that post so view it after you solve.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between a composite mode for line/edge drawing and a letter entry mode.)

Author/Opus: This is the 351st puzzle from our managing editor Serkan Yürekli.

Rules: Standard Pentominous rules.

Difficulty: 2.5 stars (estimate based off competition points; timing standards not available from our usual testers)

Solution: PDF

Note: Follow this link for other Pentominous puzzles. If you are new to this puzzle type, here are our easiest Pentominous to get started on. More Pentominous puzzles can be found in the Plenty o’ Pentominous series by Grant Fikes and Murat Can Tonta and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

See more discussion of the puzzles from the United States’ 2021 Puzzle Grand Prix on this post. Note there are some construction details and potential spoilers on that post so view it after you solve.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between shading mode and the composite Yajilin mode where left click marks cells, right click marks dots in cells or X’s on edges, left click+drag draws lines.)

Author/Opus: This is the 349th puzzle from our managing editor Serkan Yürekli.

Rules: Standard Tapa rules.

Difficulty: 3 stars (estimate based off competition points; timing standards not available from our usual testers)

Solution: PDF

Note: Follow this link for classic Tapa and this link for Tapa variations. If you are new to this puzzle type, here are our easiest Tapa puzzles to get started on. More Tapa puzzles can be found in The Art of Puzzles, in Tapa and Variations, and in our beginner-friendly collection Intro to GMPuzzles, all by Serkan Yürekli.

See more discussion of the puzzles from the United States’ 2021 Puzzle Grand Prix on this post. Note there are some construction details and potential spoilers on that post so view it after you solve.

PDF

or solve online (using our beta test of Penpa-Edit tools using a composite mode where left click inside cell shades square, left click + drag draws line segment, right click inside cell adds dot, and right click on cell edge adds an x.)

Author/Opus: This is the 401st* puzzle from Thomas Snyder, aka Dr. Sudoku (*the 400th puzzle opus number is being held for an upcoming post).

Rules: Standard Yajilin rules: Blacken some white cells and then draw a single closed loop (without intersections or crossings) through all remaining white cells. Blackened cells cannot share an edge with each other. Some cells are outlined and in gray and cannot be part of the loop. Numbered arrows in such cells indicate the total number of blackened cells that exist in that direction in the grid.

Also, in addition to the usual gray clues, some clues are white and black and act similarly to Castle Wall clues. White clues must be inside the loop and black clues must be outside the loop. White and black clues indicate the sum of the lengths of loop segments in the indicated direction.

Difficulty: 2.5 stars (estimate based off competition points; timing standards not available from our usual testers)

Solution: PDF

Note: Follow this link for classic Yajilin and this link for Yajilin variations. Follow this link for more Castle Wall puzzles.

PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: Diamonds

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

Rules: Standard Sudoku rules.

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 2:45, Master = 6:15, Expert = 12:30

Solution: PDF; a solution video is also available here.

Note: Follow this link for other classic Sudoku. If you are new to this puzzle type, here are our easiest Sudoku to get started on. More classic Sudoku puzzles can be found in The Art of Sudoku, The Art of Sudoku 2 and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: Gift Box

Author/Opus: This is the 9th puzzle from guest contributor Akash Doulani.

Rules: Standard Sudoku rules.

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 2:15, Master = 5:15, Expert = 10:30

Solution: PDF; a solution video is also available here.

Note: Follow this link for other classic Sudoku. If you are new to this puzzle type, here are our easiest Sudoku to get started on. More classic Sudoku puzzles can be found in The Art of Sudoku, The Art of Sudoku 2 and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between a composite mode for line/edge drawing and a letter entry mode.)

Theme: Triplets

Author/Opus: This is the 11th puzzle from guest contributor Takeya Saikachi.

Rules: Variation of Pentominous rules. Divide the grid into 20 pentominoes so that no two pentominoes of the same shape (including rotations/reflections) share an edge. Each number in this grid represents a clue for a different letter/pentomino as in a regular Pentominous puzzle; all instances of a number must represent the same letter. An inventory of possible pentominoes is given below the puzzle.

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 3:15, Master = 5:00, Expert = 10:00

Solution: PDF; a solution video is also available here.

Note: Follow this link for other Pentominous puzzles. If you are new to this puzzle type, here are our easiest Pentominous to get started on. More Pentominous puzzles can be found in the Plenty o’ Pentominous series by Grant Fikes and Murat Can Tonta and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between a composite mode for line/edge drawing and a letter entry mode.)

Theme: 2022

Author/Opus: This is the 346th puzzle from our managing editor Serkan Yürekli.

Rules: Variation of Pentominous rules. Some borders between pentominoes are already drawn.

Difficulty: 2 stars

Time Standards (highlight to view): Grandmaster = 1:45, Master = 2:30, Expert = 5:00

Solution: PDF; a solution video is also available here.

Note: Follow this link for other Pentominous puzzles. If you are new to this puzzle type, here are our easiest Pentominous to get started on. More Pentominous puzzles can be found in the Plenty o’ Pentominous series by Grant Fikes and Murat Can Tonta and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

PDF

or solve online (using our beta test of Penpa-Edit tools; use the tab key to alternate between shading and number entry modes)

Theme: Tetrominoes

Author/Opus: This is the 359th puzzle from our contributing puzzlemaster Grant Fikes.

Rules: Variation of Nanro rules. Label some cells with numbers to form a single connected group of labeled cells. No 2×2 group of cells may be fully labeled. Each label number must be equal to the total count of labeled cells in that bold region, and all bold regions contain at least one labeled cell. The given numbers indicate how many cells are labeled in that region (but not necessarily which cells are labeled). When two label numbers are orthogonally adjacent across a region boundary, the numbers must be different.

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 3:00, Master = 4:00, Expert = 8:00

Solution: PDF; a solution video is also available here.

Note: Follow this link for Nanro puzzles on this website and this link for variations on Nanro puzzles. If you are new to this puzzle type, here are our easiest Nanro Puzzles to get started on. More Nanro puzzles can be found in A Number o’ Nanro by Prasanna Seshadri.

PDF

or solve online (using our beta test of Penpa-Edit tools; use the tab key to alternate between shading and number entry modes)

Theme: Colosseum

Author/Opus: This is the 82nd puzzle from our contributing puzzlemaster Ashish Kumar.

Rules: Standard Nanro rules.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:45, Master = 3:30, Expert = 7:00

Solution: PDF; a solution video is also available here.

Note: Follow this link for Nanro puzzles on this website and this link for variations on Nanro puzzles. If you are new to this puzzle type, here are our easiest Nanro Puzzles to get started on. More Nanro puzzles can be found in A Number o’ Nanro by Prasanna Seshadri.

(This is a bonus “second” puzzle that is not connected to the usual Sunday Stumper difficulty from this morning.)

PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: Pairs

Author/Opus: This is the 215th puzzle from our contributing puzzlemaster Murat Can Tonta.

Rules: Standard Kurotto rules.

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 2:00, Master = 4:30, Expert = 9:00

Solution: PDF; a solution video is also available here.

Note: Follow this link for classic Kurotto puzzles and this link for variations on Kurotto puzzles. If you are new to this puzzle type, here are our easiest Kurotto to get started on. More Kurotto puzzles can be found in the ebook Kurotto by Prasanna Seshadri.