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; 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 the tab key to alternate between shading and number entry modes)

Theme: P for Puzzle

Author/Opus: This is the 384th puzzle from our managing editor Serkan Yürekli.

Rules: Standard Nanro rules.

Difficulty: 1.5 stars

Time Standards (highlight to view): Grandmaster = 1:05, Master = 1:30, Expert = 3:00

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)

Theme: Stairs

Author/Opus: This is the 383rd puzzle from our managing editor Serkan Yürekli.

Rules: Standard Sudoku rules.

Difficulty: 1.5 stars

Time Standards (highlight to view): Grandmaster = 1:20, Master = 2:00, Expert = 4:00

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)

Theme: Asterisk

Author/Opus: This is the 382nd puzzle from our managing editor Serkan Yürekli.

Rules: Standard Cross the Streams rules.

Difficulty: 1 star

Time Standards (highlight to view): Grandmaster = 1:05, Master = 1:45, Expert = 3:30

Solution: PDF and solving video.

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. More Cross the Streams can be found in these e-books in our store.

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: Big and Small

Author/Opus: This is the 381st puzzle from our managing editor Serkan Yürekli.

Rules: Standard Tapa 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 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 and 2, and in our beginner-friendly books Intro to GMPuzzles and Starter Pack 2: Tapa, all by Serkan Yürekli.

Note that we’ve referred to this style before as “Tren” and this particular variation as “Ghost Tren”. While not a common puzzle style, we are updating to the nomenclature “Parking Lot” for “Tren” and “Parking Lot (Extra Parking)” for “Ghost Tren” for this style this week.

PDF

or solve online (using our beta test of Penpa-Edit tools in Yajilin mode allowing line drawing and cell shading/unmarking; hitting tab can alternate to separate shading and edge drawing modes).

Theme: Prime Edges

Author/Opus: This is the 380th puzzle from our managing editor Serkan Yürekli.

Rules: Locate some automobiles in the grid having size 1×2 or 1×3. Each number in the grid should be part of an automobile, indicating the number of unoccupied cells the automobile can move to by traveling along its longest axis, stopped only by an edge of the grid or another automobile. No more than one number can be in an automobile; automobiles can also be placed without any numbers, with no restrictions on their ability to move. All unused cells must be part of a single connected group.

Also, see this example:

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 12:30, Master = 20:00, Expert = 40:00

Solution: PDF and solving video.

Note: Follow this link for more Parking Lot puzzles.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between a letter entry mode and a shading mode. CAPS LOCK is recommended for letter entry.)

Theme: Easy as

Author/Opus: This is the 379th puzzle from our managing editor Serkan Yürekli.

Rules: Fill some empty cells with the letters E, A, S, Y so that each row, column, and bold region contains each letter exactly once. Some cells will remain blank. The letters outside the grid indicate the first letter seen from that direction.

Difficulty: 2 stars

Time Standards (highlight to view): Grandmaster = 1:15, Master = 2:30, Expert = 5:00

Solution: PDF and solving video.

Note: Follow this link for other less common Number Placement variations.

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: Odds

Author/Opus: This is the 378th puzzle from our managing editor Serkan Yürekli.

Rules: Standard Castle Wall rules, but any two consecutive line segments cannot have the same length (i.e., on both sides of any turn, the loop must travel different lengths).

Difficulty: 4 stars

Time Standards (highlight to view): Grandmaster = 6:30, Master = 9:45, Expert = 19:30

Solution: PDF and solving video.

Note: Follow this link for more Castle Wall puzzles. If you are new to this puzzle type, here are our easiest Castle Wall puzzles to get started on. More Castle Wall puzzles can be found in our beginner-friendly collection Intro to GMPuzzles as well as the larger collection Castle Wall, both 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, a letter entry mode, and a shading mode.)

Theme: Four

Author/Opus: This is the 377th puzzle from our managing editor Serkan Yürekli.

Rules: Standard Pentominous rules. Additionally, there are some gray cells that do not contain any pentominoes. The numbers in these gray cells indicate how many pentomino regions are present in the 8 neighboring cells.

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 6:00, Master = 7:30, Expert = 15:00

Solution: PDF and solving video.

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.