The last Loop/Path puzzle is one of the “new” styles that debuted in the Breadth of America loop variety round, a Cross Border Parity Loop by Craig Kasper. (We expect this puzzle to be much harder for those who didn’t solve the three competition puzzles that preceded it.)

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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; use tab to alternate to a shading mode to mark the loop states)

Author/Opus: This is the 9th puzzle from guest contributor Craig Kasper.

Rules: Draw a single, non-intersecting loop that has two states, which are white and black. The puzzle grid has heavily shaded borders, which define areas in the grid. Whenever the loop crosses a border (including borders inside an area), it changes state from white to black or from black to white. A black circled clue provides the number of cells in each area that the loop traverses in the black state, and a white circled clue provides the number of cells in each area that the loop traverses in the white state. Each “?” represents an unknown integer, zero or larger.

See also this example:

Estimated Difficulty: 2.5-3 stars

Solution: PDF for all Loop/Path playoff puzzles.

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

The next Loop/Path puzzle, reflecting an unusual grid geometry round, is this “Trophy” Slitherlink by Serkan Yürekli. Can you figure out how all the unusual parts of the grid will mark the 30th World Puzzle Championship.

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Author/Opus: This is the 415th puzzle from our managing editor Serkan Yürekli.

Rules: Variation of Slitherlink rules. Draw a single, non-intersecting loop on an irregular grid that can only follow the lines between the dots. Numbers inside a cell indicate how many of the edges of that cell are part of the loop.

Estimated Difficulty: 2 stars

Solution: PDF for all Loop/Path playoff puzzles.

Note: Follow this link for other classic Slitherlink. If you are new to this puzzle type, here are our easiest Slitherlink puzzles to get started on. More Slitherlink puzzles can be found in our books The Art of Puzzles and Slitherlink and Variations.

The last Number Placement playoff puzzle from the World Puzzle Championship was a Skyscrapers (Gap) puzzle with an empty cell in each row and column. How long will it take you to solve David Altizio’s puzzle?

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or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between number entry modes and a shading mode to mark the unused cells.)

Author/Opus: This is the 15th puzzle from guest contributor David Altizio.

Rules: Variation of Skyscrapers rules. Insert numbers into some cells of the grid so that each row and column of the grid contains the numbers from 1 to 5 once each and one gap. Each number in the grid represents the height of a building and the clues on the outside of the grid indicate how many buildings can be “seen” when looking from that direction. Taller buildings block the view of smaller buildings.

Estimated Difficulty: 1.5 stars

Solution: PDF for all Number Placement playoff puzzles.

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

The last two closing puzzles of the World Sudoku Championship playoffs were very tricky, starting with this hybrid of Clone and Shape Sudoku by Joseph Howard.

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

Theme: 8 Rings

Author/Opus: This is the 33rd puzzle from guest contributor Joseph Howard.

Rules: Combination of Shape and Clone Sudoku rules. Insert a number from 1 to 9 into each cell so that no number repeats in any row, column, or bold region. Also, there are some numbered shapes that must be put into the grid. Shapes can be rotated, but cannot be reflected. Each shape outside the grid must appear exactly once inside the grid. Also, all remaining shaded regions of the same shape (“clones”) must be able to be paired together to include the same numbers in the same positions.

Estimated Difficulty: 3.5 stars

Solution: PDF for all playoff puzzles.

Note: Follow this link for more variations of Sudoku.

This week we are sharing the 10 puzzles that decided the World Sudoku Championship this year. There was an individual and a team round focusing on “Clone” puzzles, and the fifth playoff puzzle was such a Clone Sudoku with a Noughts and Crosses theme.

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

Theme: Noughts and Crosses

Author/Opus: This is the 413th puzzle from our managing editor Serkan Yürekli.

Rules: Standard Sudoku rules. Also, all shaded regions of the same shape (“clones”) must include the same numbers in the same positions. Numbers may repeat within a clone.

Estimated Difficulty: 3 stars

Solution: PDF for all playoff puzzles.

Note: Follow this link for more variations of Sudoku.

[This puzzle comes from the 2022 US Sudoku Grand Prix round. Multiples Sudoku was a basic idea I had not seen before in a number placement puzzle, so I decided to use it in this competition structure taking full advantage of the limitations with putting so many eight clues into the grid. It ended up being the hardest puzzle in the competition, but without given numbers I’m not sure there are any “easy” Multiples Sudoku to really construct for solvers.]

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

Theme: Too Many Eights?

Author/Opus: This is the 443rd puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules. Also, some numbers are given on the edges between two adjacent cells. Treating those cells as a two-digit number (reading left to right or top to bottom), the two-digit number must be a multiple of the clue. (For example, near a 7 clue, the two digits can be 14, 21, 28, 35, ….)

Estimated Difficulty: 4 stars

Solution: PDF

Note: Follow this link for other variations of Sudoku and this link for classic Sudoku. If you are new to this puzzle type, here are our easiest Sudoku to get started on.

Continuing another long-running tradition, we have a new Kurotto puzzle from Prasanna Seshadri marking his 32nd birthday.

(view directly for a larger image)

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

Theme: 32 on 3/2/23

Author/Opus: This is the 250th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Standard Kurotto rules. Also, numbers outside the grid show the number of separate shaded cells visible in that direction. A segment of length N in a given direction is taken as a building of height N. Buildings of height N block the view of all buildings behind them of equal or lesser height.

See also this example:

Difficulty: 4.5 stars

Time Standards (highlight to view): Grandmaster = 10:00, Master = 18:00, Expert = 36:00

Solution: To be added by next Sunday.

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.

(view directly for a larger image)

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

Theme: Cross the Streams

Author/Opus: This is the 249th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Standard Kakuro Rules. Also, some cells may remain empty but empty cells cannot share an edge with other empty cells.

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 15:30, Master = 20:00, Expert = 40:00

Solution: PDF and solving video.

Note: Follow this link for other Kakuro puzzles. More Kakuro puzzles can be found in Kakuro and Variations by Serkan Yürekli and in The Art of Puzzles 2.

PDF

or solve online (using our beta test of Penpa-Edit tools in Yajilin mode allowing line drawing and cell shading/unmarking; hitting tab can alternate to separate shading and edge drawing modes).

Theme: 2 and 3

Author/Opus: This is the 387th puzzle from our managing editor Serkan Yürekli.

Rules: Locate some automobiles in the grid having size 1×2 or 1×3. Each number in the grid should be part of an automobile, indicating the number of unoccupied cells the automobile can move to by traveling along its longest axis, stopped only by an edge of the grid or another automobile. No more than one number can be in an automobile. (Unlike other variations of this puzzle, there are no extra automobiles without numbers here.)

Also, see this example:

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 5:00, Master = 8:00, Expert = 16:00

Solution: PDF and solving video.

Note: Follow this link for more Parking Lot puzzles.

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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 number entry mode.)

Theme: 2×3 Boxes

Author/Opus: This is the 66th puzzle from our contributing puzzlemaster JinHoo Ahn.

Rules: (Hybrid of Fillomino and Snake Puzzles.) Divide the grid along the boundary lines so that every cell belongs to a snake. A snake is a one-cell-wide path at least two cells long that does not touch itself, not even diagonally. Circled cells must be at one of the ends of a snake. A snake may contain one circled cell, two circled cells, or no circled cells at all. Numbered cells must be part of a snake with a length of exactly that number of cells. A snake may contain one number, multiple identical numbers, or no numbers at all. Two snakes of the same length cannot touch each other horizontally or vertically. Cells with an X cannot be an end of a snake.

Also see this example:

Difficulty: 1 star

Time Standards (highlight to view): Grandmaster = 0:40, Master = 1:00, Expert = 2:00

Solution: PDF and solving video.

Note: Follow this link for more Snake Pit puzzles. Follow these links for other Fillomino or Snake puzzles.