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Theme: 20-20 Vision

Author/Opus: This is the 1st puzzle from guest contributor Teddy Tan.

Rules: Standard Thermo-Sudoku rules.

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 5:00, Master = 7:30, Expert = 15:00

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

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

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Author/Opus: This is the 47th puzzle from our contributing puzzlemaster Tom Collyer.

Rules: Standard Masyu rules.

Difficulty: 2.5 stars

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

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

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.

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Theme: Catch-22

Author/Opus: This is the 14th puzzle from guest contributor Zoltán Horváth.

Rules: Standard Star Battle rules. Two stars per row, column, and region.

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 3:30, Master = 5:15, Expert = 10:30

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

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

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Theme: Meteor

Author/Opus: This is the 2nd puzzle from guest contributor Sam Cappleman-Lynes.

Rules: Standard Star Battle rules. Two stars per row, column, and region.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:30, Master = 4:00, Expert = 8:00

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

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

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Theme: Speed of Light and Speed of Sound

Author/Opus: This is the 20th puzzle from guest contributor Bryce Herdt.

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: 3 stars

Time Standards (highlight to view): Grandmaster = 2:45, Master = 5:15, Expert = 10:30

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

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.

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Theme: 345

Author/Opus: This is the 393rd puzzle from Thomas Snyder, aka Dr. Sudoku.

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: 3 stars

Time Standards (highlight to view): Grandmaster = 2:45, Master = 4:45, Expert = 9:30

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

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.

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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.