Dr. Sudoku Prescribes #147 – Star Battle

Star Battle by Thomas Snyder

PDF

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

Theme: “The Star Battle for Christmas”

Rules: Standard Star Battle rules. Two stars per row, column, and region. Note: the shading is just to emphasize the theme and is not involved in the solve.

Answer String: For each row from top to bottom, enter the number of the first column from the left where a star appears. Enter these numbers as a single string with no separators.

Time Standards (highlight to view): Grandmaster = 2:15, Master = 5:15, Expert = 10:30

Solution: PDF

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 book Star Battle by JinHoo Ahn, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

This is a Melon puzzle. (22 – Hexa Briquets)

Hexa Briquets by Palmer Mebane

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.)

Theme: Clue Symmetry

Rules: Place some blocks of three hexagons connected in a line (briquets) into the grid so that they do not overlap themselves or the numbered cells. For each numbered cell, the top clue indicates how many of the surrounding cells containing a briquet segment; the bottom clue indicates how many different briquets are in the surrounding cells. All cells that are not covered by briquets, including the numbered cells, must be part of a single connected group. Or see this example from the WPC instruction booklet.

Answer String: For each marked row, enter the length in cells of each group of connected cells that are part of briquets. Separate each row’s entry with a comma (eg “5,16,33,14”).

Time Standards (highlight to view): Grandmaster = 5:30, Master = 8:30, Expert = 17:00

Solution: PDF

The Puzzle Robot #23 – Easy as Japanese Sums

Easy as Japanese Sums by Serkan Yürekli

PDF

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

Theme: Clue Symmetry and Logic

Rules: Hybrid of Easy as ABCD and Japanese Sums puzzle types. Fill some cells with digits 1-5 so that each row and column contains each digit from 1 to 5 exactly once as well as two empty cells. Numbers outside the grid indicate the sum of all digits in the first connected group in that direction as in a Japanese Sums puzzle. For example, the row X345X12 could have a 12 clue on the left or a 3 on the right. Or see here.

Answer String: Enter the marked rows from left to right, separating the two rows by a comma. Use an X (capital letter) for each empty square.

Time Standards (highlight to view): Grandmaster = 3:30, Master = 4:15, Expert = 8:30

Solution: PDF

Note: Follow this link for other Japanese Sums puzzles.

This is a Melon puzzle. (21 – Neighbors)

Neighbors by Palmer Mebane

PDF

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

Theme: WPC Practice

Rules: Place a digit 1, 2, or 3 into each empty cell so that each digit appears exactly three times in each row and column. All cells are either white or gray. A digit in a white cell must share an edge with at least one cell containing the same digit. A digit in a gray cell cannot share an edge with any cell containing the same digit.

Answer String: Enter the digits from left to right in the marked rows, separating the rows with a comma.

Time Standards (highlight to view): Grandmaster = 10:00, Master = 15:00, Expert = 30:00

Solution: PDF

The Puzzle Robot #22 – Pentomino Puddles

Pentomino Puddles by Serkan Yürekli

PDF

or solve online (using our beta test of Penpa-Edit tools in a composite mode for line/edge drawing)

Theme: Grandmaster Puzzles (GMP in the shapes)

Rules: Divide each of the three shapes into four pentominoes so that all 12 pentominoes are present exactly once across the three shapes. An inventory of pentominoes is given below the puzzle; rotations and reflections of these shapes are allowed.

Answer String: Enter the capital letters for the pentominoes sitting in each cell along the indicated long row. Enter as a single string of 14 characters.

Time Standards (highlight to view): Grandmaster = 2:30, Master = 5:30, Expert = 11:00

Solution: PDF

This is a Melon puzzle. (19 – Pento Coral)

Pento Coral by Palmer Mebane

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: “Hard” Practice (this was a WPC puzzle style) — in contrast to this post.

Rules: Place each of the 11 pentominoes into the grid exactly once, with rotations and reflections allowed, to form a valid “Coral”. In a Coral puzzle, all blackened areas are connected, but no group of 2×2 cells is entirely blackened. Also, there are no unshaded areas enclosed by the coral (meaning each unshaded cell must have a path through its edges with other unshaded cells to a border). Numbers outside the grid indicate the lengths of groups of shaded cells in that row/column, but not necessarily in order.

Or see this example from the 22nd WPC instruction booklet.

Answer String: Enter the identities of the pentominoes (one capital letter for each, even if in multiple cells) appearing in the marked rows from left to right (eg “ILN,WVXT”).

Time Standards (highlight to view): Grandmaster = 10:00, Master = 20:00, Expert = 40:00

Solution: PDF

The Puzzle Robot #20 – Graffiti

Graffiti by Serkan Yürekli

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; an additional shading mode is available by hitting the tab button if that is preferred.)

Theme: Clue Symmetry and Logic

Rules: Blacken some cells and then draw a single non-intersecting loop through all remaining white cells. Outside clues indicate the size of all groups of blackened cells in that row or column in order. There must be at least one white cell between each of these groups. When no clues are given, any number of cells may be shaded in that row/column. Or see here.

Answer String: For each marked column, enter the length in cells of the longest vertical segment. Enter 0 if there are no vertical segments. Enter these values as a single string (eg “230124”).

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

Solution: PDF

This is a Melon puzzle. (17 – Nurikabe Scrabble)

Nurikabe Scrabble by Palmer Mebane

(View image directly for larger form.)

PDF

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

Theme: String Lengths

Rules: Variation of Nurikabe and Scrabble/Criss-Cross puzzles.

Place the 12 number strings into the grid, reading from left to right or from top to bottom, so they are all connected criss-cross style and also form a valid Nurikabe ocean. No unlisted string can appear anywhere, not even two-character ones, and the strings do not occupy any 2×2 area. The remaining white cells are part of islands as in a Nurikabe puzzle. Each island is represented by one number in the grid which equals its size in cells.

Or see this example from the 22nd WPC instruction booklet.

Answer String: For each column from left to right, enter the total count of zeroes from the entered strings. Enter the result as a single string (eg “401120…”)

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

Solution: PDF

Detuned Broadcast #12: TomTom

TomTom by Tom Collyer

PDF

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

Theme: Nothing Important

Rules: Standard TomTom rules, using digits from 1-6.

Answer String: Enter the 1st row from left to right, followed by a comma, followed by the 6th row from left to right.

Time Standards (highlight to view): Grandmaster = 5:15, Master = 8:00, Expert = 16:00

Solution: PDF

Note: Follow this link for other classic TomTom. If you are new to this puzzle type, here are our easiest TomTom to get started on.

This is a Melon puzzle. (15 – Smashed Sums – False)

Smashed Sums by Palmer Mebane

PDF

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

Theme: 22nd WPC in 2013 (the shaded box is just meant to accentuate the theme and has no role in solving). This puzzle type appeared in Round 7 of the WPC from the Serbian constructors under the name “False Doppelblock”

Rules: Fill each row and column of the grid with the numbers 1-6 and two blackened cells. In this false variation, clue numbers outside the grid are either one higher or one lower than the sum of the digits between the two blackened cells in that row/column. True sums can equal zero if the black cells touch. Or see here, but remember this puzzle is a “false” variation with +1/-1 clues unlike that example.

Answer String: Enter the 1st row from left to right, followed by a comma, followed by the 8th row from left to right. Use an X (capital letter) for each blackened square.

Time Standards (highlight to view): Grandmaster = 10:00, Master = 17:30, Expert = 35:00

Solution: PDF