From Prasanna: “This puzzle is meant to be a culmination of 10 years of authoring puzzles. I want to especially thank GMPuzzles for accommodating these special puzzles every year even if it may not have fit the regular schedules. I also see this puzzle as a “reset” of sorts, and I’ll get back to simple ideas to celebrate my next few birthdays, and then see where that takes me. These last 10 years have been a fantastic experience and I’d like to take this moment to thank the puzzle community as a whole for being a huge part of my journey.”

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or solve online (using our beta test of Penpa-Edit tools; note that the default puzzle info is too long — even for an url shortener — so copy and paste all the text in this file into the “Load” option in the upper-right of the penpa-edit interface to access.)

Theme: The Journey

Author/Opus: This is the 201st puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Please see first two pages of the PDF for a detailed description of the rules and more background on the theme of the puzzle.

Difficulty: 5 stars?

Solution: PDF

Prasanna is celebrating two milestones this week and we will have two special large puzzles. The first one here recognizes Prasanna’s 200th submission on GMPuzzles, and combines three of the styles where Prasanna has written books for our e-store.

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or solve online (using our beta test of Penpa-Edit tools; while solution checking is not enabled, if you are comfortable with the different tool selection options you should be able to fully solve the puzzle in this mode too.)

Theme: Linking 200 cells

Author/Opus: This is the 200th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules:

Grids 1-2: Follow regular LITS rules. Between the two LITS grids, the corresponding white cells can never both be shaded, while the corresponding gray cells must be identical in the three 200-shaped regions.

Use the LITS solutions and your ingenuity to discover the needed constraints for Grids 3-4. For Grid 3, you will find that some gray circles must change color to white or black.

Grid 3: Follow regular Balance Loop rules. Additionally, the loop must cross itself if it passes through a gray circle. The loop must go straight throught the gray circle both times; in one direction the path behaves as if the circle is white with equal loop lengths, and in the other direction the path behaves as if the circle is black with unequal loop lengths. It is not required that the loop pass through all of the gray circles (but it must pass through all white and black circles). (See also the image below.)

Grid 4: Follow regular Yajilin rules.

When taken together, the grids yield a short final answer! Send this (less than five character) string to hiddencontest at gmpuzzles dot com by March 14th, 2021 to be eligible to win an e-book by Prasanna Seshadri. The contest is now closed and results summarized here.

Difficulty: 5 stars?

Solution: PDF

PDF

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

Theme: Only 4 You

Author/Opus: This is the 317th puzzle from our managing editor Serkan Yürekli.

Rules: Standard Balance Loop rules. Also, each row and column must contain exactly two stars. Stars cannot be placed in adjacent cells that share an edge or corner, and all stars must be on empty cells not used by the loop.

Difficulty: 4 stars

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

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

Note: Follow this link for other Balance Loop puzzles. If you are new to this puzzle type, here are our easiest Balance Loop Puzzles to get started on. More Balance Loops can be found in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli and in Balance Loop by Prasanna Seshadri and Murat Can Tonta.

PDF

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: Antisymmetry

Author/Opus: This is the 190th puzzle from our contributing puzzlemaster Murat Can Tonta.

Rules: Standard Balance Loop rules. Also, all cells must be visited by the loop.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:15, Master = 3:15, Expert = 6:30

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

Note: Follow this link for other Balance Loop puzzles. If you are new to this puzzle type, here are our easiest Balance Loop Puzzles to get started on. More Balance Loops can be found in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli and in Balance Loop by Prasanna Seshadri and Murat Can Tonta.

PDF

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

Theme: Broken Frame

Author/Opus: This is the 374th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Star Battle rules. Also, some region boundaries are missing, but all given borders must separate cells in different regions.

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 5:00, Master = 7:45, Expert = 15:30

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 books Star Battle by JinHoo Ahn and Star Battle 2 by JinHoo Ahn and Murat Can Tonta, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

This is a bonus Sunday puzzle for Valentine’s Day, and one more puzzle to conclude a full week of puzzles from JinHoo Ahn.

PDF

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: Valentine

Author/Opus: This is the 18th puzzle from our contributing puzzlemaster JinHoo Ahn.

Rules: Standard Masyu rules. Also, some white circles may be shaded to become black circles. (Stylistically, here the white circles are white with red borders and the black circles are filled, red circles.)

Difficulty: 4 stars

Time Standards (highlight to view): Grandmaster = 3:30, Master = 8:00, Expert = 16:00

Solution: PDF

Note: Follow this link for other Masyu variations and this link for classic Masyu. 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.

PDF

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

Theme: Groups

Author/Opus: This is the 17th puzzle from our new contributing puzzlemaster JinHoo Ahn.

Rules: Variation of Cross the Streams rules. Instead of their usual meaning, clues refer to the distribution of the white cells. The shaded cells must still obey the regular rules (connectivity, no 2×2 squares).

Difficulty: 4 stars

Time Standards (highlight to view): Grandmaster = 6:30, Master = 10:30, Expert = 21:00

Solution: PDF; a solution video (with info on an Easter Egg for this puzzle) is also available here.

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

PDF

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

Theme: Open Middle

Author/Opus: This is the 16th puzzle from our new contributing puzzlemaster JinHoo Ahn.

Rules: Variation of Yajilin rules. Instead of their usual meaning, interior clues refer to the total sum of the lengths of loop segments in the given direction. (An equivalent way to understand these values is to count the number of cell borders crossed by the loop in that direction.)

See also this example:

Difficulty: 3 stars

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

Solution: PDF; a solution video (with info on an Easter Egg for this puzzle) is also available here.

Note: Follow this link for classic Yajilin and this link for Yajilin variations. If you are new to this puzzle type, here are our easiest Yajilin to get started on. More Yajilin puzzles can be found in The Art of Puzzles 2, in Yajilin by Murat Can Tonta and Prasanna Seshadri, and in our beginner-friendly book Logic Puzzles 101.

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: Knight Steps

Author/Opus: This is the 15th puzzle from our new contributing puzzlemaster JinHoo Ahn.

Rules: Variation of Cave rules. Instead of their usual meaning, interior clues indicate the number of shaded cells in neighboring cells, including diagonally adjacent cells. Cells with numbers cannot be shaded.

See also this example:

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 4:00, Master = 5:15, Expert = 10:30

Solution: PDF; a solution video (with info on an Easter Egg for this puzzle) is also available here.

Note: Follow this link for other 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.

PDF

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

Theme: Double X

Author/Opus: This is the 14th puzzle from our new contributing puzzlemaster JinHoo Ahn.

Rules: Variation of Arrow Sudoku rules. Instead of the usual meaning, the digit in the circled cell of each arrow must equal the product of the digits along the path.

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 3:30, Master = 4:45, Expert = 9:30

Solution: PDF; a solution video (with info on an Easter Egg for this puzzle) is also available here.

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.