(Note: This bonus puzzle is at a Saturday+ difficulty, and is being posted today to mark the occasion of Prasanna’s birthday.)

(View image directly for larger form.)

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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: 26 on 03/02

Author/Opus: This is the 152nd puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: This puzzle combines Yajisan-Kazusan with Tapa with additional rules.

Left grid = Yajisan-Kazusan (No 2×2): Shade some cells black so that all unshaded number and arrow clues indicate the exact count of shaded cells in the given direction (all counts extend through gaps in the grid). Shaded cells cannot share an edge, and all white cells must remain connected as part of a single contiguous group. It is allowed to shade over some of the numbered cells; a shaded over clue may or may not be true. Also, no 2×2 area inside the grid can be fully white.

Right grid = Tapa: Shade some empty cells black to create a single connected wall. 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, and the shaded cells cannot form a 2×2 square anywhere in the grid.

Additional rule 1: Clues in the middle of the grids indicate the sum or the difference of the number of shaded cells in that row between the grids (possibly both).

Additional rule 2: The shading of the green outlined regions is equivalent in the two grids in the shared cells (if the cell labeled “A” in the illustration below is shaded in one grid it must be shaded in both grids). Note that the 3 and 2 share all locations except for the bottom vertical stem of the numbers which is shifted.

Answer String: For each marked row, enter the length in cells of each of the unshaded segments from left to right in the Yajisan-Kazusan followed by the length of each of the shaded segments from left to right in the Tapa. Separate each row’s entry from the next with a comma (but do not use commas in between the Yajisan-Kazusan and Tapa entry parts in a given row). Enter both digits for any two-digit large segment in an entry.

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

Solution: PDF

PDF

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

Theme: Sum of 1 & 2 (for Randy Rogers)

Author/Opus: This is the 146th puzzle from our contributing puzzlemaster Serkan Yürekli.

Rules: Place the digits 1-9 in some of the cells, so that no digit is repeated in any row or column. Numbers on the outside of the grid indicate the sums of adjacent digit groups in that row or column, in order. Each sum is separated by at least one unused cell.

Answer String: Enter the 1st row from left to right, followed by a comma, followed by the 10th row from left to right. Use a capital X for empty cells.

Time Standards (highlight to view): Grandmaster = 18:00, Master = 32:00, Expert = 1:04:00

Solution: PDF

Note: Follow this link for other Japanese Sums puzzles.

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

Theme: Diamonds (for Chris Green)

Author/Opus: This is the 150th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Classic Sudoku Rules. Also, some arrow shapes are in the grid; the sum of the digits along the path of each arrow must equal the digit in the circled cell. Some thermometer shapes are in the grid; digits must be strictly increasing from the round bulb to each flat end. Finally, some diamond shapes are in the grid; the labeled diamonds below the grid must be placed in some order onto the shapes in the grid. The labeled diamonds can be rotated but cannot be reflected.

Answer String: Enter the 1st row from left to right, followed by a comma, followed by the 9th row from left to right.

Time Standards (highlight to view): Grandmaster = 5:15, Master = 10:45, Expert = 21:30

Solution: PDF

Note: Follow this link for other less common variations of Sudoku and this link for classic Sudoku. If you are new to this puzzle type, here are our easiest Sudoku to get started on. More Arrow and Thermo-Sudoku puzzles can be found in The Art of Sudoku 2.

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Theme: Logical

Author/Opus: This is the 1st puzzle from guest contributor Dan Adams.

Rules: Place digits into some cells and shade all remaining cells so that: each dodecagon contains the digits 1-9 exactly once; digits in cells sharing a vertex with a black triangle add up to the indicated clue number without repeats; and shaded cells cannot share an edge with another shaded cell.

Answer String: Enter the digits in the marked central rows (triangle, hexagon, triangle, …). Use a capital X for shaded cells. Separate each row with a comma. The example has the key “8178XX,243”.

Time Standards (highlight to view): Grandmaster = 16:00, Master = 32:00, Expert = 1:04:00

Solution: PDF

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

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: Clue Symmetry and Logic

Author/Opus: This is the 7th puzzle from guest contributor Walker Anderson.

Rules: Standard Cave rules.

Answer String: Enter the length in cells of each of the cave segments from left to right for the marked rows, starting at the top. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 3:45, Master = 8:45, Expert = 17:30

Solution: PDF; a solution video is available here.

Note: Follow this link for other classic Caves. 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 The Art of Puzzles and in Roger Barkan’s Colossal Cave Collection.

PDF

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

Theme: Logical

Author/Opus: This is the 6th puzzle from guest contributor Roger Barkan.

Rules: Combination of Star Battle and Cave. Place digits into two cells in every row, column, and region of the top grid (one cell in the example). Digits cannot touch, not even diagonally. The numbers in the upper-left of each region indicate the identity of the digit to be entered in that region. The digits must form a valid cave puzzle (which can be solved on the bottom grid).

Answer String: Enter the length in cells of each of the cave segments from left to right for the marked rows, starting at the top. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 9:00, Master = 15:30, Expert = 31:00

Solution: PDF

Note: Follow this link for other classic Caves. 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 The Art of Puzzles and in Roger Barkan’s Colossal Cave Collection.

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: Clue Symmetry and Logic (Puzzle #63 in the Colossal Cave Collection).

Author/Opus: This is the 5th puzzle from guest contributor Roger Barkan.

Rules: Standard Cave rules.

Answer String: Enter the length in cells of each of the cave segments from left to right for the marked rows, starting at the top. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 5:00, Master = 7:15, Expert = 14:30

Solution: PDF

Note: Follow this link for other classic Caves. 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 The Art of Puzzles and in Roger Barkan’s Colossal Cave Collection.

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: Clue Symmetry and Logic

Author/Opus: This is the 58th puzzle from our contributing puzzlemaster Murat Can Tonta.

Rules: Standard Tapa rules. Also, similar to Nurikabe, each clue cell is part of an island of horizontally and vertically connected white cells. Islands are allowed to touch diagonally. Islands may contain at most one clue cell, and the area of the island must be one of the numbers in the clue (as an example, if a clue is 15, then the island containing that clue must be either 1 cell or 5 cells large).

See also this example:

Answer String: Enter the length in cells of each of the shaded segments from left to right for the marked rows, starting at the top. Separate each row’s entry from the next with a comma.

Time Standards (highlight to view): Grandmaster = 5:00, Master = 13:15, Expert = 26:30

Solution: PDF

Note: Follow this link for other Tapa variations and this link for classic Tapa. 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 and in Tapa and Variations, both by Serkan Yürekli.

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: Almost Antisymmetric

Author/Opus: This is the 21st puzzle from our contributing puzzlemaster Carl Worth.

Rules: Combination of Masyu and Balance Loop rules. In each horizontal row, all the circles obey the same rules, which are Masyu rules or Balance Loop rules. You must determine what rule applies to each row in order to form the single loop that solves the puzzle.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 7:00, Master = 9:30, Expert = 19:00

Solution: PDF; a solution video is available here.

Note: Follow this link for other Masyu and Balance Loop 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: Just One (in Roman Numerals)

Author/Opus: This is the 20th puzzle from our contributing puzzlemaster Carl Worth.

Rules: Standard Pentominous rules.

Answer String: Enter the letter associated with the pentomino occupying each cell in the marked rows from left to right and in the marked columns from top to bottom, separating the groups with a comma. Use CAPITAL LETTERS!

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

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.