Sunday Stumper: Tapa (Mastermind) by Serkan Yürekli

Since 2021, we have posted some extra difficult Sunday Stumpers, about once a month. These will be quite tough puzzles, but with a logical path to be found (and solution videos to help). This first Sunday Stumper of 2022 is a Tapa variation from Serkan Yürekli.

Tapa (Mastermind) by Serkan Yürekli

(view directly for a larger image)

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between shading mode and the composite Yajilin mode where left click marks cells, right click marks dots in cells or X’s on edges, left click+drag draws lines.)

Theme: Mastermind 2022

Author/Opus: This is the 357th puzzle from our managing editor Serkan Yürekli.

Rules: Standard Tapa rules. Also, the numbers given between the grids show the total number of black cells in the same position in that row or column. A row or column without such a clue may have any number of common black cells including zero.

See also this example:

Tapa (Mastermind) example by Serkan Yürekli

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 33:00, Master = 55:00, Expert = 1:50:00

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

Note: Follow this link for classic Tapa and this link for Tapa variations. If you are new to this puzzle type, here are our easiest Tapa puzzles to get started on. More Tapa puzzles can be found in The Art of Puzzles, in Tapa and Variations, and in our beginner-friendly collection Intro to GMPuzzles, all by Serkan Yürekli.

Skyscrapers (Sum) by Ashish Kumar

Skyscrapers (Sum) by Ashish Kumar

PDF

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

Theme: The Rising of 2022

Author/Opus: This is the 84th puzzle from our contributing puzzlemaster Ashish Kumar.

Rules: Variation of Skyscrapers; each clue represents the sum of the heights of the visible buildings in that direction.

Difficulty: 4 stars

Time Standards (highlight to view): Grandmaster = 5:45, Master = 11:00, Expert = 22:00

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

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

Battleships (Minesweeper) by Jin Hoo Ahn

Battleships (Minesweeper) by JinHoo Ahn

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between ship placement and shading modes. In ship placement mode, right click gives sea, left click gives circle/square, left click and drag for rounded ships.)

Theme: 2021 and 2022

Author/Opus: This is the 38th puzzle from our contributing puzzlemaster JinHoo Ahn.

Rules: Variation of standard Battleships rules. Instead of exterior clues, clues inside the grid indicate the number of adjacent squares, including diagonally adjacent squares, containing ship segments. Ships do not sit on cells with numbers. Use the indicated fleet.

Difficulty: 2 stars

Time Standards (highlight to view): Grandmaster = 1:15, Master = 2:15, Expert = 4:30

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

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

Meandering Word Search by Serkan Yürekli

See more discussion of the puzzles from the United States’ 2021 Puzzle Grand Prix on this post. Note there are some construction details and potential spoilers on that post so view it after you solve.

Meandering Word Search by Serkan Yürekli

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab mode to shift between letter entry, line drawing, and shape entry — for word list marking — modes)

Author/Opus: This is the 356th puzzle from our managing editor Serkan Yürekli.

Rules: Combination of Word Search and Meandering Words rules (see prior posts, and below). Each bold word in the given list should be either located as in a Word Search (possibly filling in missing letters in the grid) or should be placed in an outlined region as in a Meandering Words puzzle.

Meandering Words rules: Place a letter into each empty cell so that each outlined area has exactly one bold word from the given list. Cells that contain the same letter cannot be placed in adjacent cells that share an edge or corner. Each outlined area must contain the word from the first letter to the last letter such that consecutive letters within an outlined area are orthogonally adjacent. (In other words, for each region it must be possible to draw a path that starts at the first letter and ends at the last letter, going through each other cell exactly once.)

Word Search rules: Locate the bold words in the given list in the grid, running in one of eight possible directions horizontally, vertically, or diagonally. Some letters in the middle of the grid are missing and must be discovered while solving.

Difficulty: 4.5 stars (estimate based off competition points; timing standards not available from our usual testers)

Solution: PDF

Note: Follow this link for other Word puzzles.

SkyTomTom by Thomas Snyder

See more discussion of the puzzles from the United States’ 2021 Puzzle Grand Prix on this post. Note there are some construction details and potential spoilers on that post so view it after you solve.

TomTom by Thomas Snyder

PDF

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

Author/Opus: This is the 407th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Skyscrapers rules; also standard TomTom rules. Use the integers 1-7.

Difficulty: 3 stars (estimate based off competition points; timing standards not available from our usual testers)

Solution: PDF

Note: Follow this link for classic Skyscrapers puzzles and this link for variations on Skyscrapers puzzles. Follow this link for classic TomTom and this link for TomTom variations.

Star Battleships by Thomas Snyder

See more discussion of the puzzles from the United States’ 2021 Puzzle Grand Prix on this post. Note there are some construction details and potential spoilers on that post so view it after you solve.

Battleships by Thomas Snyder

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between ship placement and shading modes. In ship placement mode, right click gives sea, left click gives circle/square, left click and drag for rounded ships.)

Author/Opus: This is the 404th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Variation of Battleships rules; only two ship segments can belong in each marked region.

Difficulty: 2.5 stars (estimate based off competition points; timing standards not available from our usual testers)

Solution: PDF

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

Pentominous (Spiral Galaxies) by Serkan Yürekli

See more discussion of the puzzles from the United States’ 2021 Puzzle Grand Prix on this post. Note there are some construction details and potential spoilers on that post so view it after you solve.

Pentominous by Serkan Yürekli

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 letter entry mode.)

Author/Opus: This is the 353rd puzzle from our managing editor Serkan Yürekli.

Rules: Standard Pentominous rules. Also, some circle clues are given in the grid which must be at the center of symmetry for a rotationally-symmetric pentomino shape.

Difficulty: 2.5 stars (estimate based off competition points; timing standards not available from our usual testers)

Solution: PDF

Note: Follow this link for other Pentominous puzzles. If you are new to this puzzle type, here are our easiest Pentominous to get started on. More Pentominous puzzles can be found in the Plenty o’ Pentominous series by Grant Fikes and Murat Can Tonta and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

LITS (Tapa) by Serkan Yürekli

See more discussion of the puzzles from the United States’ 2021 Puzzle Grand Prix on this post. Note there are some construction details and potential spoilers on that post so view it after you solve.

LITS (Tapa) by Serkan Yürekli

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between shading mode and the composite Yajilin mode where left click marks cells, right click marks dots in cells or X’s on edges, left click+drag draws lines.)

Author/Opus: This is the 350th puzzle from our managing editor Serkan Yürekli.

Rules: Standard LITS rules: Shade exactly four connected cells in each outlined region, to form an L, I, T, or S tetromino, so that the following conditions are true: (1) All shaded cells are connected with each other; (2) No 2×2 group of cells can be entirely shaded black; (3) When two tetrominoes in adjacent regions share an edge, they must not be of the same type (L, I, T, or S), regardless of rotations or reflections.

Also, the number clues follow standard Tapa rules: Numbers in a cell indicate the length of consecutive shaded blocks in the neighboring cells. If there is more than one number in a cell, then there must be at least one white (unshaded) cell between the black cell groups. Cells with numbers cannot be shaded.

Difficulty: 1.5 stars (estimate based off competition points; timing standards not available from our usual testers)

Solution: PDF

Note: Follow this link for more variations of LITS and this link for classic LITS. Follow this link for classic Tapa and this link for Tapa variations.

Yajilin (Castle Wall) by Thomas Snyder

See more discussion of the puzzles from the United States’ 2021 Puzzle Grand Prix on this post. Note there are some construction details and potential spoilers on that post so view it after you solve.

Yajilin (Castle Wall) by Thomas Snyder

PDF

or solve online (using our beta test of Penpa-Edit tools using a composite mode where left click inside cell shades square, left click + drag draws line segment, right click inside cell adds dot, and right click on cell edge adds an x.)

Author/Opus: This is the 401st* puzzle from Thomas Snyder, aka Dr. Sudoku (*the 400th puzzle opus number is being held for an upcoming post).

Rules: Standard Yajilin rules: Blacken some white cells and then draw a single closed loop (without intersections or crossings) through all remaining white cells. Blackened cells cannot share an edge with each other. Some cells are outlined and in gray and cannot be part of the loop. Numbered arrows in such cells indicate the total number of blackened cells that exist in that direction in the grid.

Also, in addition to the usual gray clues, some clues are white and black and act similarly to Castle Wall clues. White clues must be inside the loop and black clues must be outside the loop. White and black clues indicate the sum of the lengths of loop segments in the indicated direction.

Difficulty: 2.5 stars (estimate based off competition points; timing standards not available from our usual testers)

Solution: PDF

Note: Follow this link for classic Yajilin and this link for Yajilin variations. Follow this link for more Castle Wall puzzles.

Pentominous (Star Battle) by Grant Fikes

Pentominous (Star Battle) by Grant Fikes

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between a composite mode for line/edge drawing, a letter entry mode, and shading / shape entry modes depending on how you want to mark the stars.)

Author/Opus: This is the 360th puzzle from our contributing puzzlemaster Grant Fikes.

Rules: Combination of Pentominous and Star Battle. Place stars into some cells so that there are two stars in each row and column; no two stars can touch, even diagonally. Then divide the rest of the grid into 16 regions each containing 5 cells. Regions with the same shape (including rotations/reflections) cannot share an edge. A cell with a letter in it must be part of the pentomino shape normally associated with that letter; an inventory of pentominoes is given below the puzzle.

Difficulty: 4 stars

Time Standards (highlight to view): Grandmaster = 5:30, Master = 10:15, Expert = 20:30

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

Note: Follow this link for other Pentominous puzzles. If you are new to this puzzle type, here are our easiest Pentominous to get started on. More Pentominous puzzles can be found in the Plenty o’ Pentominous series by Grant Fikes and Murat Can Tonta and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.