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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: All Threes

Author/Opus: This is the 27th puzzle from guest contributor Joseph Howard.

Rules: Standard Cave rules. (The puzzle is on a hexagonal grid and cells now see in a maximum of six possible directions.)

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 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 year, we have started to have 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 sixth Sunday Stumper is a Kakuro puzzle with some extra clue shadings to indicate connected digit subsets for some of the entries.

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

Theme: Eye

Author/Opus: This is the 209th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Standard Kakuro Rules. Also, whenever two multi-digit entries intersect and the set of digits in one entry is a subset of the set of digits in the other entry, the cell preceding each of those entries (either giving the entry’s clue or indicating that the entry is unclued) is shaded in gray. A shaded cell may be shaded because of its Across entry, Down entry, or both. Any clue cell that is not shaded does not have a multi-digit entry intersecting its Across or Down entries with a shared subset of digits. Any set of digits is considered a subset of itself.

See also this example:

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 20:00, Master = 30:00, Expert = 1:00:00

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

Note: Follow this link for classic Kakuro and this link for Kakuro variations. More Kakuro puzzles can be found in Kakuro and Variations by Serkan Yürekli and in The Art of Puzzles 2.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between edgex mode where left click+drag draws lines and right click marks X’s and a star placement mode)

Author/Opus: This is the 332nd puzzle from our managing editor Serkan Yürekli.

Rules: Standard Slitherlink rules. Also, each row and column must contain exactly two stars (one in the example). Stars cannot touch each other, even diagonally, and all stars must be inside the loop. Stars cannot be placed in the numbered cells.

See also this example:

Difficulty: 4.5 stars

Time Standards (highlight to view): Grandmaster = 7:00, Master = 14:15, Expert = 28:30

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

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

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or solve online (using our beta test of Penpa-Edit tools in edgex mode where left click+drag draws lines and right click marks X’s)

Theme: Inside Job

Author/Opus: This is the 1st puzzle from guest contributor Priyam Bhushan.

Rules: Standard Slitherlink rules. Also, numbers outside the grid show the number of separate loop segments visible in that direction. A segment of length N in a given direction is taken as a building of height N. Buildings of height N block the view of all buildings behind them of equal or lesser height.

See also this example:

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 3:45, Master = 5:15, Expert = 10:30

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

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

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

Theme: Sssssssss

Author/Opus: This is the 7th puzzle from guest contributor Takeya Saikachi.

Rules: Standard LITS rules. Also, the letters outside the grid indicate the first tetromino encountered in the corresponding direction. Or see this:

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:15, Master = 3:30, Expert = 7:00

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

Note: Follow this link for more variations of LITS and this link for classic LITS. If you are new to this puzzle type, here are our easiest LITS to get started on. More LITS puzzles can be found in LOTS O’ LITS by Grant Fikes and Prasanna Seshadri, in The Art of Puzzles 2, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

(view directly for a larger image)

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

Theme: HEX Week

Author/Opus: This is the 25th puzzle from guest contributor Joseph Howard.

Rules: Fill some cells with stars so that each row (in a horizontal or either of two diagonal directions) and bold region contains the indicated number of stars. Stars cannot be placed in adjacent cells that share an edge.

Difficulty: 4 stars

Time Standards (highlight to view): Grandmaster = 5:15, Master = 9:45, Expert = 19:30

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.

(view directly for a larger image)

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

Theme: Five Rings

Author/Opus: This is the 6th puzzle from guest contributor Takeya Saikachi.

Rules: Standard Kurotto rules. Also, the grid is hexagonal.

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 6:45, Master = 9:15, Expert = 18:30

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

Note: Follow this link for classic Kurotto puzzles and this link for variations on Kurotto puzzles. If you are new to this puzzle type, here are our easiest Kurotto to get started on. More Kurotto puzzles can be found in the ebook Kurotto by Prasanna Seshadri.

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

Theme: Mini Hexes

Author/Opus: This is the 384th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Variation of LITS. Shade exactly four cells in each outlined region to form an S, L, I, C, or Y tetrahex. When all regions have been shaded, the following conditions must be true:
1) All shaded cells will be connected through a network of adjacent shaded cells;
2) No three shaded cells will share a common vertex;
3) When two tetrahexes share an edge in adjacent regions, they must not be the same type (S, L, I, C, or Y), regardless of potential rotations or reflections.

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 5:00, Master = 8:00, Expert = 16:00

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

Note: Follow this link for more variations of LITS and this link for classic LITS. If you are new to this puzzle type, here are our easiest LITS to get started on. More LITS puzzles can be found in LOTS O’ LITS by Grant Fikes and Prasanna Seshadri, in The Art of Puzzles 2, 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: Diamond

Author/Opus: This is the 19th puzzle from guest contributor Bryce Herdt.

Rules: Draw a single, non-intersecting loop that passes through all cells. The loop must form a 60 degree angle in all the cells with black circles, a 120 degree angle in all the cells with gray circles, and a 180 degree angle (straight segment) in all the cells with white circles.

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 4:15, Master = 7:30, Expert = 15:00

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

Note: Follow this link for other Loop/Path puzzles.

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.)

Theme: Cyclops

Author/Opus: This is the 24th puzzle from guest contributor Joseph Howard.

Rules: Divide the grid into tetrahexes (four-cell regions) so that no two tetrahexes of the same shape (including rotations/reflections) share an edge. A cell with a letter in it must be part of the tetrahex shape normally associated with that letter. An inventory of tetrahexes is given below the puzzle but not all shapes must be used.

Difficulty: 2 stars

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

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.