This style, whose name means “Triangular Numbers” in English and has also been called “Four Directions Loop” elsewhere, was originally created by the Indian team that organized the 2017 World Puzzle Championship as part of an instructionless team round. More Mukkonn Enn will be in our upcoming Loop Variety Collection 2.

PDF

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

Theme: Sequences

Author/Opus: This is the 386th puzzle from our managing editor Serkan Yürekli.

Rules: Draw a single, non-intersecting loop that passes through the center of all cells, including clue cells; the loop may either go straight through or turn at each clue. Each clue cell is divided into four sections; if a number is present in a section and the loop travels in that direction, then the number represents the length of the straight loop segment in that direction, measured from the clue cell to the cell where the loop turns. If the loop does not travel in that direction, then the number means nothing.

Also see this example:

Difficulty: 1 star

Time Standards (highlight to view): Grandmaster = 0:45, Master = 1:00, Expert = 2:00

Solution: PDF and solving video.

Note: Follow this link for other Loop/Path puzzles. More Mukkonn Enn puzzles are in the book Loop Variety Collection 2.

PDF

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

Theme: Downward Spiral

Author/Opus: This is the 429th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules: Insert a number from 1 to 9 into each cell so that no number repeats in any row, column, or bold region.

Difficulty: 3 stars

Time Standards (highlight to view): Grandmaster = 4:15, Master = 5:45, Expert = 11:30

Solution: PDF and solving video.

Note: Follow this link for other classic Sudoku. If you are new to this puzzle type, here are our easiest Sudoku to get started on. More classic Sudoku puzzles can be found in The Art of Sudoku, The Art of Sudoku 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; in composite Star Battle mode a left click places a star, right click in a cell marks off the cell, and a right click on an edge or corner marks in a dot as a placement note.)

Theme: Diagonal Borders

Author/Opus: This is the 65th puzzle from our contributing puzzlemaster JinHoo Ahn.

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

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 1:40, Master = 3:30, Expert = 7:00

Solution: PDF and solving video.

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 collections Intro to GMPuzzles by Serkan Yürekli and Starter Pack 5: Star Battle by JinHoo Ahn.

PDF

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: Similar Instances

Author/Opus: This is the 27th puzzle from our contributing puzzlemaster Takeya Saikachi.

Rules: Standard Slitherlink rules.

Difficulty: 2 stars

Time Standards (highlight to view): Grandmaster = 1:00, Master = 2:00, Expert = 4:00

Solution: PDF and solving video.

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.

PDF

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

Theme: Square Dance

Author/Opus: This is the 428th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard TomTom rules, using the integers 1-6.

Difficulty: 2 stars

Time Standards (highlight to view): Grandmaster = 1:40, Master = 2:30, Expert = 5:00

Solution: PDF and solving video.

Note: Follow this link for classic TomTom and this link for TomTom variations. If you are new to this puzzle type, here are our easiest TomTom to get started on. More TomTom puzzles can be found in the TomTom 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; 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: Identical Pairs

Author/Opus: This is the 385th puzzle from our managing editor Serkan Yürekli.

Rules: Standard Tapa rules.

Difficulty: 1.5 stars

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

Solution: PDF and solving video.

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 1, 2, and 3, and in our beginner-friendly books Intro to GMPuzzles and Starter Pack 2: Tapa, all 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 number entry mode.)

Theme: Small Straights

Author/Opus: This is the 397th puzzle from our contributing puzzlemaster Grant Fikes.

Rules: Standard Fillomino rules.

Difficulty: 1 star

Time Standards (highlight to view): Grandmaster = 0:40, Master = 1:00, Expert = 2:00

Solution: PDF and solving video.

Note: Follow this link for classic Fillomino and this link for Fillomino variations. If you are new to this puzzle type, here are our easiest Fillomino puzzles to get started on. More Fillomino puzzles can be found in The Art of Puzzles, in Fill o’ Fillomino and Fill o’ Fillomino 2 by Grant Fikes, and in our beginner-friendly books Logic Puzzles 101 and Starter Pack 1: Fillomino.

PDF

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

Theme: Four by Four

Author/Opus: This is the 64th puzzle from our contributing puzzlemaster JinHoo Ahn.

Rules: Variation of Nanro rules with Tapa clue elements: Label some cells with numbers to form a single connected group of labeled cells; no 2×2 group of cells may be fully labeled. Each bold region must contain at least one labeled cell. Each number must equal the total count of labeled cells in that region. Numbers in a gray cell indicate the length of consecutive labeled cells in its neighbors. If there is more than one number in a gray cell, then there must be at least one white (not labeled) cell between the labeled cell groups. When two numbers are orthogonally adjacent across a region boundary, the numbers must be different.

Also see this example:

Difficulty: 4.5 stars

Time Standards (highlight to view): Grandmaster = 9:00, Master = 13:00, Expert = 26:00

Solution: PDF and solving video.

Note: Follow this link for Nanro puzzles on this website and this link for variations on Nanro puzzles. If you are new to this puzzle type, here are our easiest Nanro Puzzles to get started on. More Nanro puzzles can be found in A Number o’ Nanro by Prasanna Seshadri.

PDF

or solve online (using our beta test of Penpa-Edit tools; use the tab key to alternate between shading, number entry, and composite loop drawing modes)

Theme: Parquet

Author/Opus: This is the 23rd puzzle from guest contributor Bryce Herdt.

Rules: Variation of Nanro rules. Label some cells with numbers to form a single non-intersecting loop; no 2×2 group of cells may be fully labeled, but the loop may touch itself orthogonally or diagonally. The region boundaries divide the loop into segments, and each region must have at least one segment. Numbers denote the length in cells of each segment within a region; all numbers in a region must be the same. When two numbers from different segments are orthogonally adjacent, the numbers must be different. (Consequently, segments in the same region must not share an edge.)

Also see this example:

Difficulty: 4 stars

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

Solution: PDF and solving video.

Note: Follow this link for Nanro puzzles on this website and this link for variations on Nanro puzzles. If you are new to this puzzle type, here are our easiest Nanro Puzzles to get started on. More Nanro puzzles can be found in A Number o’ Nanro by Prasanna Seshadri.

PDF

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

Theme: Twelve Hexominoes

Author/Opus: This is the 12th puzzle from guest contributor David Altizio.

Rules: Standard Nanro rules.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:30, Master = 3:45, Expert = 7:30

Solution: PDF and solving video.

Note: Follow this link for Nanro puzzles on this website and this link for variations on Nanro puzzles. If you are new to this puzzle type, here are our easiest Nanro Puzzles to get started on. More Nanro puzzles can be found in A Number o’ Nanro by Prasanna Seshadri.