[This puzzle comes from the 2022 US Sudoku Grand Prix round. Shape Sudoku is a variation I created many years ago where careful assignment of the givens to each of the shapes can lead to fun and narrow solving paths, so I really enjoy setting these kinds of puzzles. I had one big idea for the “eight” theme which you’ll certainly see while working through to the solution.]

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between Sudoku number entry mode and a shading mode to manage the shape inventory.)

Theme: Big Eight

Author/Opus: This is the 436th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Shape Sudoku rules.

Estimated Difficulty: 4 stars

Solution: PDF

Note: Follow this link for other Shape Sudoku. More Shape Sudoku are in Masterpiece Sudoku Mix 8.

[This puzzle comes from the 2022 US Sudoku Grand Prix round. This puzzle is the last of three classic Sudoku that did not have a visual theme, however (spoiler for hidden theme and solving path) the digit eight is still a key part of the theme. This is a “just one cell” type Sudoku, one of my trademarks, where the first move is very limited and I’m 99% sure your first digit placement will be an eight in box 8 even if you’ll find it by thinking of other numbers first.]

PDF

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

Theme: Hidden Theme

Author/Opus: This is the 435th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules.

Estimated Difficulty: 3 stars

Solution: PDF

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 our e-store, including in The Art of Sudoku, The Art of Sudoku 2 and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

[This puzzle comes from the 2022 US Sudoku Grand Prix round. This puzzle is the second of three classic Sudoku that did not have a visual theme, however (spoiler for hidden theme and solving path) the digit eight is still a key part of the theme, one of three isolated digits in their rows/columns that are part of several X-wing patterns in the grid; in this case the eight is not as key initially as the other numbers but it still highlights a way to look at the grid and make progress.]

PDF

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

Theme: Hidden Theme

Author/Opus: This is the 434th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules.

Estimated Difficulty: 3 stars

Solution: PDF

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 our e-store, including in The Art of Sudoku, The Art of Sudoku 2 and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

[This puzzle comes from the 2022 US Sudoku Grand Prix round. This puzzle is the first of three classic Sudoku that did not have a visual theme, however (spoiler for hidden theme and solving path) the digit eight is still a key part of the theme, one of a pair of digits that sets up a lot of pointing pairs in the grid at the start. You can get the center number — an eight — by following just the one number through four symmetric pointing pairs.]

PDF

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

Theme: Hidden Theme

Author/Opus: This is the 433rd puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules.

Estimated Difficulty: 2.5 stars

Solution: PDF

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 our e-store, including in The Art of Sudoku, The Art of Sudoku 2 and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

[This puzzle comes from the 2022 US Sudoku Grand Prix round. This puzzle continues the “eight” theming by combining a visual theme (two clear eights in the grid) with an unusual parity-based split of the digits that sets up different kinds of deductions to get odds on the right side of the grid and evens on the left side.]

PDF

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

Theme: Odd and Even

Author/Opus: This is the 432nd puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules.

Estimated Difficulty: 2.5 stars

Solution: PDF

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 our e-store, including in The Art of Sudoku, The Art of Sudoku 2 and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

[This puzzle comes from the 2022 US Sudoku Grand Prix round written entirely by me. This puzzle demonstrates another visual approach to an “eight” theme. While there are no 8s in the grid, all the givens appear in clear two by four block groups which is a pattern that sets up some nice if easy geometric deductions.]

PDF

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

Theme: Two by Fours

Author/Opus: This is the 431st puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules.

Estimated Difficulty: 2 stars

Solution: PDF

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 our e-store, including in The Art of Sudoku, The Art of Sudoku 2 and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

[This puzzle comes from the 2022 Sudoku Grand Prix round written by me, which was the eighth round that ran in early August including 8/8. The round used a theme of “eight” across all the puzzles. This easy classic Sudoku has a strong visual theme with just three given digits, two eights in the corners and a big “eight” made out of other numbers only.]

PDF

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

Theme: Three Eights

Author/Opus: This is the 430th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules.

Estimated Difficulty: 2 stars

Solution: PDF

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 our e-store, including 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: Parity Lines

Author/Opus: This is the 7th puzzle from guest contributor R. Kumaresan.

Rules: Standard Sudoku rules.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:15, Master = 4:30, Expert = 9:00

Solution: PDF and solving video.

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; in default linex mode: left-click+drag draws line, right click marks X on edge)

Theme: Odd vs. Even

Author/Opus: This is the 103rd puzzle from our contributing puzzlemaster Ashish Kumar.

Rules: Draw a single loop in the grid which may cross itself orthogonally, but otherwise does not touch or retrace itself. The clue numbers to the left/right of the rows indicate the number of squares visited by the nearest section of the loop that travels horizontally in the rows. The clue numbers to the top/bottom of the columns indicate the number of squares visited by the nearest section of the loop that travels vertically in the columns.

Also, see this example:

Difficulty: 2 stars

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

Solution: PDF and solving video.

Note: Follow this link for other Round Trip puzzles. Some more Round Trip puzzles can be found in the book Loop Variety Collection by Ashish Kumar and Murat Can Tonta.

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: Empty Frame

Author/Opus: This is the 398th puzzle from our contributing puzzlemaster Grant Fikes.

Rules: Standard Nanro rules.

Difficulty: 2 stars

Time Standards (highlight to view): Grandmaster = 1:15, Master = 1:45, Expert = 3:30

Solution: PDF and solving video.

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.