[This is a repost from our archives with new notes at the top (original post here): This very difficult Consecutive Sudoku reveals the two sides of this genre (the positive rule for consecutive digits and the negative “anti”-rule for nonconsecutive digits) with a narrow solving path to connect the top and the bottom.

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Theme: Jekyll and Hyde – digits but no bars up top, bars but no digits down below. Master both sides to solve this puzzle.

Rules: Standard Consecutive Sudoku rules.

Estimated Difficulty*: 3.5 stars

Time Standards (highlight to view): Grandmaster = 4:30, Master = 9:00, Expert = 18:00

Solution: PDF and solving video.

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

[This is a repost from our archives with new notes at the top (original post here): The first set of Masyu puzzles ends with a grid that almost has “twisted” symmetry meaning antisymmetry of white and black circles. Several less conventional steps are required to find the one true loop in this challenging Masyu.]

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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)

Theme: Almost Twisted! – Slightly imperfect, but more difficult as a result.

Rules: Standard Masyu rules.

Estimated Difficulty*: 2.5 stars

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

Solution: PDF and solving video; advice on solving this puzzle was also posted in “Ask Dr. Sudoku #5“.

Note: Follow this link for classic Masyu and this link for Masyu variations. If you are new to this puzzle type, here are our easiest Masyu to get started on. More Masyu puzzles can be found in The Art of Puzzles and in our beginner-friendly book Logic Puzzles 101.

[This is a repost from our archives with new notes at the top (original post here): In this second Consecutive Sudoku from our first month of puzzles, the “boxes” theme works across four sets of numbers and two consecutive bar groups. Those elements should get you started, but some of the key solving may also occur in the less orderly corners where large runs of digits are implied by the bars and others by the absence of bars.

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

Theme: Boxes upon Boxes

Rules: Standard Consecutive Sudoku rules.

Estimated Difficulty*: 3 stars

Time Standards (highlight to view): Grandmaster = 3:45, Master = 5:30, Expert = 11:00

Solution: PDF

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

[This is a repost from our archives with new notes at the top (original post here): Making images of smiley faces in puzzle form is one way I try to make the world at least 1% happier. This Wednesday Masyu has a couple less common lookahead steps but should continue to be a good introduction to the genre for those without much prior familiarity (this was a bigger gap in 2013 when the puzzle was written than in 2023).]

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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)

Theme: Smiley Face – our first (but probably not last) use of this theme here.

Rules: Standard Masyu rules.

Estimated Difficulty*: 1.5 stars

Time Standards (highlight to view): Grandmaster = 0:40, Master = 1:15, Expert = 2:30

Solution: PDF

Note: Follow this link for classic Masyu and this link for Masyu variations. If you are new to this puzzle type, here are our easiest Masyu to get started on. More Masyu puzzles can be found in The Art of Puzzles and in our beginner-friendly book Logic Puzzles 101.

[This is a repost from our archives with new notes at the top (original post here): Consecutive Sudoku is one of the most basic variations of Sudoku to uses properties of the numbers to help place sets of digits into the grid. Wei-Hwa Huang and I included it in Mutant Sudoku with several artistic themes, despite the challenges that the “anti”-rule forces into puzzles for having no consecutive digits when bars are not present. In future years, GMPuzzles prioritized Consecutive Pairs Sudoku which only uses the positive information of known pairs for cleaner themes and easier solving. But as we look back on our past, this week will show examples of me pushing the limits of a style with two kinds of constraints, positive and negative, across every pair of cells.

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

Theme: Hashtag Fun? A consecutive sudoku with a large # in the middle.

Rules: Standard Consecutive Sudoku rules.

Estimated Difficulty*: 2 stars

Time Standards (highlight to view): Grandmaster = 2:00, Master = 3:00, Expert = 6:00

Solution: PDF

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

[This is a repost from our archives with new notes at the top (original post here): Our first Loop/Path puzzle genre on the site was Masyu, a style from Nikoli that focuses on white and black clue elements on a big grid, sharing some visual inspiration from Go. The distinct rules of going straight through and turning at the “pearls” leads to different kinds of logic as seen in this “25th” puzzle from over a decade ago.]

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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)

Theme: Our 25th prescription! Enjoy this easy Masyu puzzle.

Rules: Standard Masyu rules.

Estimated Difficulty*: 1 star

Time Standards (highlight to view): Grandmaster = 0:30, Master = 0:45, Expert = 1:30

Solution: PDF

Note: Follow this link for classic Masyu and this link for Masyu variations. If you are new to this puzzle type, here are our easiest Masyu to get started on. More Masyu puzzles can be found in The Art of Puzzles and in our beginner-friendly book Logic Puzzles 101.

[This is a repost from our archives with new notes at the top (original post here): The third arrow Sudoku puzzle in our GMPuzzles introduction series contains a lot of “split” arrows with multiple paths all equaling the same total sum. Steady progress going arrow by arrow around the grid should let you eventually find the unique answer.]

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

Theme: Multi-arrow Challenge! Also, there is a 1-9 “digit pangram” in the nine givens.

Rules: Standard Arrow Sudoku rules.

Estimated Difficulty*: 4 stars

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

Solution: PDF and solving video.

Note: Follow this link for more Arrow Sudoku. If you are new to this puzzle type, here are our easiest Arrow Sudoku to get started on. More Arrow Sudoku puzzles can be found in The Art of Sudoku 2 and Masterpiece Sudoku Mix 3.

[This is a repost from our archives with new notes at the top (original post here): The last Cave puzzle in our starting week has some interesting border clues that should set up for a different kind of solving path if you are paying attention.

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or solve online (using our beta test of Penpa-Edit tools; use tab to shift between shading mode and the linex mode where left click+drag draws lines and right click marks X’s)

Theme: An Almost Perfect 10? The border of this Cave puzzle is almost completely uniform.

Rules: Standard Cave rules.

Estimated Difficulty*: 3 stars

Time Standards (highlight to view): Grandmaster = 3:15, Master = 6:00, Expert = 12:00

Solution: PDF and solving video.

Note: Follow this link for classic Caves and this link for Cave variations. If you are new to this puzzle type, here are our easiest Cave Puzzles to get started on. More Cave puzzles can be found in Roger Barkan’s Colossal Cave Collection, in The Art of Puzzles, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

[This is a repost from our archives with new notes at the top (original post here): The best Arrow Sudoku puzzles usually have a few fully constrained arrow clues at the start to be the “seeds” for the logical path to the solution. Can you find where these seeds are in this “Flower Blossom” theme?

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

Theme: Flower Blossom – The cells with arrows look a little like the petals of a flower and are heavily involved in the solving path.

Rules: Standard Arrow Sudoku rules.

Estimated Difficulty*: 2.5 stars

Time Standards (highlight to view): Grandmaster = 3:45, Master = 5:30, Expert = 11:00

Solution: PDF

Note: Follow this link for more Arrow Sudoku. If you are new to this puzzle type, here are our easiest Arrow Sudoku to get started on. More Arrow Sudoku puzzles can be found in The Art of Sudoku 2 and Masterpiece Sudoku Mix 3.

[This is a repost from our archives with new notes at the top (original post here): This puzzle highlights a lot of the standard Cave logical thinking (including a rule about checkerboards that we mentioned in a prior post needs to be in your toolbox for this genre). If you are struggling with this cave puzzle, an “Ask Dr. Sudoku” written piece may be worth referring to.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between shading mode and the linex mode where left click+drag draws lines and right click marks X’s)

Theme: “23” – Both the original posting date in 2013 (Jan 23), and a fine number for themed logic puzzles, such as the Map Puzzles from Bang 23.

Rules: Standard Cave rules.

Estimated Difficulty*: 2.5 stars

Time Standards (highlight to view): Grandmaster = 1:45, Master = 3:30, Expert = 7:00

Solution: PDF

Note: Follow this link for classic Caves and this link for Cave variations. If you are new to this puzzle type, here are our easiest Cave Puzzles to get started on. More Cave puzzles can be found in Roger Barkan’s Colossal Cave Collection, in The Art of Puzzles, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.