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: Surrounded!

Author/Opus: This is the 154th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Slitherlink rules. Also, there are some sheep (marked S) that must be inside the loop and some wolves (marked W) that must be outside the loop.

Answer String: Enter the length in cells of each of the internal loop segments following the arrows for the marked rows, starting at the top. Separate each row’s entry with a comma.

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

Solution: PDF

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

PDF

or solve online (using our beta test of Penpa-Edit tools; ue tab to alternate between edgex mode where left click+drag draws lines and right click marks X’s and shading and number entry modes.)

Theme: Symmetry and Logic

Rules: Variation of standard Slitherlink rules. First, place the ten dominoes given below the grid into the gray areas, without overlapping, to form a valid Slitherlink puzzle; dominoes can be rotated. Solve the resulting Slitherlink following normal rules. (Note: The set of digits placed into the grid from the dominoes is unique, but the assignment of dominoes need not be unique.)

Answer String: Enter the length in cells of each of the internal loop 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 = 7:30, Master = 17:30, Expert = 35:00

Solution: PDF

PDF

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

Theme: Logic

Rules: Variation on Masyu and Battleships.

Normal Masyu rules. Also, all cells not used by the loop must contain ships from the indicated Battleships fleet, and all ships must be placed. Ships cannot touch each other, even diagonally. All of the given clues are Masyu clues (and none are submarines).

Answer String: For each row from top to bottom, enter the number of the first column from the left where a ship segment appears. If the row is empty, enter 0. Enter these numbers as a single string with no separators. (This is normal Battleships answer entry.)

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

Solution: PDF

I’m sure many of you were expecting ANOTHER version of the Christmas Tree puzzle from the last two weeks. I mean, I did get a very nice Double Back from Robert Vollmert (which cannot be confused as a Star Battle or a LITS). But posting such a puzzle wouldn’t be a surprise.

No, today’s Sunday Surprise comes from the pile of submissions I’ve received over the year from Hans van Stippent, who played with the usual rules of Skyscrapers a bit by hiding some of the cells from consideration. It yielded a very interesting puzzle which is Hans’ gift to you this Sunday.

PDF

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

Theme: New Variation/Logic

Rules: Standard Sudoku rules. Also, standard Skyscrapers rules. Additionally, the cells in gray are “underground” and cannot be seen for any of the outside skyscraper clues (think of them as starting with a negative sign if necessary). As an example, the 4 in row 2 refers only to seeing four buildings in columns 3 through 7, even if there is a 9 in column 1 or column 2 as that 9 cannot be seen.

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

Solution: PDF

(view image directly for a larger form)

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 number entry mode, and shading for this variation.)

Theme: Symmetry and Logic

Rules: Variation of standard Fillomino rules. All polyominoes of same size besides 4 cannot touch. But all tetrominoes must be connected to form a valid LITS solution. All 4 clues have been replaced by tetromino letters.

Answer String: For each cell in the marked rows, enter the area of the polyomino it belongs to. For the tetrominoes, instead of numbers use capital letters (L, I, T, S) in the appropriate cells. Start with the 10th column, followed by a comma, followed by the 14th column.

Time Standards (highlight to view): Grandmaster = 12:30, Master = 18:00, Expert = 36:00

Solution: PDF

Note: Follow this link for other classic Fillomino and this link for more variations on Fillomino puzzles. If you are new to this puzzle type, here are our easiest Fillomino puzzles to get started on.

PDF

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

Theme: WPC Practice

Rules: Enter digits 1 through 4 into some cells so that each row and column contains each digit exactly once. Also, along the snail (from the upper-left corner and spiraling to the center) digits must occur in 1-2-3-4-1-2-3-4-… order. Some clues are given in the grid in the form of lit digital segments. Each of these cells must contain a digit, and that digit must have that segment lit in the form shown below the puzzle.

Or see an example from the WPC instructions using 1 to 3 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 = 6:00, Master = 8:30, Expert = 17:00

Solution: PDF

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between Number entry mode and a shading mode to help track complete clues.)

Theme: Clue Symmetry, and Very Hard WPC Practice

Rules: Variation of Sudoku. Place integers from -4 to 4 into each cell so that each row, column, and region contains each integer from -4 to 4 exactly once. The numbers outside the grid represent the sum of all integers between that clue and the zero in that row/column. Some cells inside the grid already contain an integer but no sign is given. It is part of the puzzle to determine if these values are positive or negative. An example using -2 to 2 from the WPC instructions is here.

Answer String: Enter the numbers (ignoring sign) from left to right in the marked rows, separating each row with a comma (eg “123401234,431023412”).

Time Standards (highlight to view): Grandmaster = 10:00, Master = 16:00, Expert = 32:00

Solution: PDF

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 on edges)

Theme: Clue Symmetry and Logic

Rules: In this variation of Tapa, the wall is in the form of a single non-intersecting loop. Clues inside the grid represent the number of neighboring cells visited by the loop; if there is more than one number in a cell, each number should be represented with a separate loop segment. There is no 2×2 rule of Tapa in this puzzle. This example image should help:

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. Separate each row’s entry with a comma. For the example, this would be “11,12”.

Time Standards (highlight to view): Grandmaster = 1:30, Master = 2:15, Expert = 4:30

Solution: PDF

Note: Follow this link for other Tapa-Like Loop puzzles. If you are new to this puzzle type, here are our easiest Tapa puzzles to get started on.

PDF

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

Theme: Nine High

Rules: Variant of Skyscrapers rules. The numbers outside the grid represent the sum of the buildings seen in that row or column. For example, if a row is 12534, the clue from the left would be an 8 (1+2+5) and from the right would be a 9 (4+5).

Answer String: Enter the 2nd row from left to right, followed by a comma, followed by the 5th row from left to right.

Time Standards (highlight to view): Grandmaster = 1:00, Master = 2:15, Expert = 4:30

Solution: PDF

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