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 shading mode.)

Theme: Double Ring

Author/Opus: This is the 392nd puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Variation of Spiral Galaxies. In addition to the standard rules, some circles are shaded gray and must belong to galaxies containing two gray circles, not one, with the circles in rotationally symmetric spots for those galaxies.

Difficulty: 4.5 stars

Time Standards (highlight to view): Grandmaster = 7:00, Master = 13:15, Expert = 26:30

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

Note: Follow this link for classic Spiral Galaxies puzzles on this website and this link for variations on Spiral Galaxies puzzles. If you are new to this puzzle type, here are our easiest Spiral Galaxies Puzzles to get started on. More Spiral Galaxies can be found in The Art of Puzzles 2.

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 shading mode.)

Author/Opus: This is the 84th puzzle from our contributing puzzlemaster John Bulten.

Rules: Standard Spiral Galaxies rules. Also, there may not be four consecutive cells that are part of a galaxy in any row or column.

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 4:00, Master = 6:30, Expert = 13:00

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

Note: Follow this link for classic Spiral Galaxies puzzles on this website and this link for variations on Spiral Galaxies puzzles. If you are new to this puzzle type, here are our easiest Spiral Galaxies Puzzles to get started on. More Spiral Galaxies puzzles can be found in The Art of Puzzles 2.

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 shading mode.)

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

Rules: Standard Spiral Galaxies rules.

Difficulty: 2.5 stars

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

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

Note: Follow this link for classic Spiral Galaxies puzzles on this website and this link for variations on Spiral Galaxies puzzles. If you are new to this puzzle type, here are our easiest Spiral Galaxies Puzzles to get started on. More Spiral Galaxies puzzles can be found in The Art of Puzzles 2.

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 shading mode.)

Theme: White Hole

Author/Opus: This is the 207th puzzle from our contributing puzzlemaster Murat Can Tonta.

Rules: Standard Spiral Galaxies rules.

Difficulty: 2.5 stars

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

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

Note: Follow this link for classic Spiral Galaxies puzzles on this website and this link for variations on Spiral Galaxies puzzles. If you are new to this puzzle type, here are our easiest Spiral Galaxies Puzzles to get started on. More Spiral Galaxies puzzles can be found in The Art of Puzzles 2.

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 shading mode.)

Theme: Down the Middle

Author/Opus: This is the 353rd puzzle from our contributing puzzlemaster Grant Fikes.

Rules: Standard Spiral Galaxies rules.

Difficulty: 2 stars

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

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

Note: Follow this link for classic Spiral Galaxies puzzles on this website and this link for variations on Spiral Galaxies puzzles. If you are new to this puzzle type, here are our easiest Spiral Galaxies Puzzles to get started on. More Spiral Galaxies puzzles can be found in The Art of Puzzles 2.

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 shading mode.)

Theme: Triplets

Author/Opus: This is the 78th puzzle from our contributing puzzlemaster Ashish Kumar.

Rules: Standard Spiral Galaxies rules.

Difficulty: 1.5 stars

Time Standards (highlight to view): Grandmaster = 0:50, Master = 1:20, Expert = 2:40

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

Note: Follow this link for classic Spiral Galaxies puzzles on this website and this link for variations on Spiral Galaxies puzzles. If you are new to this puzzle type, here are our easiest Spiral Galaxies Puzzles to get started on. More Spiral Galaxies puzzles can be found in The Art of Puzzles 2.

After many years of publishing elegant, hand-crafted puzzles across multiple genres in focused e-books and one-off collections, we have decided to start a more regular quarterly publication where every 3 months we will feature selections from six different categories of puzzles. Today marks the release of Grandmaster Puzzles Quarterly: Volume 1, which has 60 total puzzles split across these genres:

– 7 Sudoku and 3 Killer Sudoku
– 7 TomTom and 3 TomTom (Different Set)
– 7 Star Battle and 3 Star Battle (Isometric)
– 7 Tapa and 3 Tapa (Line)
– 7 Fillomino and 3 Fillomino (Non-consecutive)
– 7 Yajilin and 3 Yajilin (Regional)

We are already pretty far along in preparing volume 2, which will be even larger than the first volume, and we are continuing to consider additional features to put into this recurring series over time. So please try out this first volume, and then share any feedback you have so we can continue to make a great quarterly publication.

At the end of the year (at the release of volume 2), we expect to offer some options to subscribe to this series of books to receive them at a discount.

The recent mix of “Last Days of SUM-mer” arithmetic puzzles is collected in this PDF and the solutions are in this PDF.

The daily solution videos are on the posts and linked below:

This next week of puzzles will be themed around Spiral Galaxies puzzles.

We have recently added several more Penpa versions of puzzles to the site, completing the main entries for TomTom and LITS styles, to bring us to over 775 puzzles digitized so far this year. The six completed sudoku genres and six completed puzzle genres are listed on our Penpa Notes page.

Later today we’ll be posting the first issue of a new book series, Grandmaster Puzzles Quarterly 1. This book has 60 total puzzles, with six sections containing 7 “regular” puzzles and one variation with 3 more puzzles. The first issue focuses on Sudoku, TomTom, Star Battle, Tapa, Fillomino, and Yajilin. Each section is meant to resemble a full week of GMPuzzles on the web, but packed with extra content. While this first issue took more time than expected to prepare, our managing editor Serkan Yürekli and contributing authors are pretty far along with Grandmaster Puzzles Quarterly 2 which will be out by the end of the year with an even larger size.

PDF

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

Theme: It’s T Time

Author/Opus: This is the 215th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Standard Sudoku rules. Also, the sum of the numbers in each cage must equal the value given in the upper-left corner of that cage. Numbers cannot repeat inside a cage.

Difficulty: 4.5 stars

Time Standards (highlight to view): Grandmaster = 11:15, Master = 19:00, Expert = 38:00

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

Note: Follow this link for more Killer Sudoku and this link for classic Sudoku. More Killer Sudoku puzzles can be found in Killer Sudoku by Serkan Yürekli.

PDF

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

Theme: Magic Squares

Author/Opus: This is the 32nd puzzle from our contributing puzzlemaster JinHoo Ahn.

Rules: Place the digits in the indicated range (1-9) in some of the cells so that no digit is repeated in any row or column. Numbers on the outside of the grid indicate the sums of adjacent digit groups in that row or column, in order. Each sum is separated by at least one unused cell.

Difficulty: 4.5 stars

Time Standards (highlight to view): Grandmaster = 7:15, Master = 20:00, Expert = 40:00

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

Note: Follow this link for other Japanese Sums puzzles.