(View image directly for larger form.)

(After solving the puzzle (or before, if you desire) look at this additional image for another challenge.)

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. Note that the default puzzle info is too long — even for an url shortener — so copy and paste all the text in this file into the “Load” option in the upper-right of the penpa-edit interface to access. You can then also open a new tab and copy in all this file for the final additional challenge.)

Theme: Clue Symmetry and Logic

Author/Opus: This is the 100th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: This puzzle combines styles that involve shading cells. All rules are standard for the given puzzle types (Tapa, Light and Shadow, Nurikabe, Kurotto, and Cave) which appear in the indicated spots of the grid (see below).

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.

Cave: (The inside of the cave with the numbered cells is shaded here!) Shade some cells to form a single connected group — the cave — with no enclosed, unshaded cells. In other words, all unshaded cells must be connected by other unshaded cells to an edge of the grid. All numbered cells must be a part of the cave, with each number indicating the total count of cells connected vertically and horizontally to the numbered cell including the cell itself.

Additionally, there are two diamonds made out of cells in each grid. Each cell in the smaller diamond corresponds to two cells in the same position in the larger diamond (see example below). The corresponding cells must differ in their shading (i.e., if a cell in the smaller diamond is shaded, both corresponding cells in the larger diamond are unshaded; if a cell in the smaller diamond is unshaded, both corresponding cells in the larger diamond are shaded).

Answer String: Enter the answer to the additional challenge in ALL CAPITAL LETTERS (no spaces)

Time Standards (highlight to view): Grandmaster = 25:00, Master = 32:30, Expert = 1:05:00

Solution: PDF

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 to mark off cells).

Theme: Just Pentomino Letters

Author/Opus: This is the 86th puzzle from our contributing puzzlemaster Serkan Yürekli.

Rules: Locate the given words in the grid, reading across and down. All words should be interconnected and no words other than those in the word list should appear. All cells that are not part of the crisscross belong to one of the twelve pentominoes. Pentominoes can only touch each other at corners. Rotations and reflections of the pentominoes are allowed. The letters inside the grid are either part of the words, or part of a pentomino (and they must belong to a pentomino shape with that letter).

Or see this example:

Answer String: Enter all crisscross letters (ignore pentominoes) from left to right for the marked rows, starting at the top. Separate each row’s entry with a comma. Use CAPITAL LETTERS.

Time Standards (highlight to view): Grandmaster = 7:45, Master = 10:15, Expert = 20:30

Solution: PDF

Note: Follow this link for other puzzles involving Pentominoes.

Serkan finished this “Giant” puzzle shortly after we started our break. We figured this Gapped Kakuro would be a fun, challenging Sunday Surprise that might take several Sundays to complete.

(view directly for a larger image)

PDF

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

Theme: Sum Time

Author/Opus: This is the 72nd puzzle from our contributing puzzlemaster Serkan Yürekli.

Rules: Standard Kakuro Rules. Also, some cells may remain empty but empty cells cannot share an edge with other empty cells.

Answer String: Enter the values in the white cells in the marked rows from left to right, ignoring all black cells, and separating the rows with a comma. Use a capital ‘X’ for any blank cell.

Time Standards (highlight to view): Grandmaster = 50:00, Master = 1:30:00, Expert = 3:00:00

Solution: PDF

Note: Follow this link for other Kakuro puzzles.

For those who thought there would be no special puzzles on Sundays in 2014: SURPRISE!

This very creative submission comes from Nikolai Beluhov. And like his earlier Matryoshka Fillomino, this is a gift that keeps on giving. Starting with a challenging Fillomino puzzle, erasing all of the 4s leaves a Slitherlink. Then erasing all of the 3s leaves a Tapa. Then erasing all of the 2s gives a Simple Loop (treating the 1s as blackened cells).

PDF

Fillomino

Slitherlink

Tapa

Simple Loop

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between a Composite Edgesub mode for Fillomino and Slitherlink, a shading mode for Tapa, a number entry mode for Fillomino, and a line drawing mode for Simple Loop.)

Rules: Standard Fillomino rules.
Then standard Slitherlink rules.
Then standard Tapa rules.
Then Simple Loop rules (draw a single closed loop, without intersections or crossings, through all empty cells; cells with 1s cannot be visited by the loop).

Answer String: None for this puzzle; simply click solved if finished.

Solution: PDF

PDF

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

Theme: Indian States (contributed by GMPuzzles to the Indian Puzzle Championship)

Author/Opus: This is the 180th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Variation of Nurikabe rules. Here, the islands are made up of words given in the list below the grid. The words must appear “snake-like” without forming 2×2 white squares or branching. Each given letter belongs to a separate word from the list. This example from the IPC instructions may be helpful:

Answer String: Enter the length in cells of each of the black segments (the unnumbered, connected “ocean”) 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 = 4:00, Master = 5:30, Expert = 11:00

Solution: PDF; a solution video is available here.

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

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: Birthday Mystery

Author/Opus: This is the 108th puzzle from our contributing puzzlemaster Grant Fikes.

Rules: Draw a single loop of horizontal and vertical segments that passes through all of the white cells (and only the white cells) exactly once. Like last week’s puzzles, there is also a second puzzle style that this grid can be solved as. Doing so will help you find a secret answer word.

Answer String: Enter the final answer word in ALL CAPITAL LETTERS.

Solution: PDF

Time Standards (highlight to view): Grandmaster = 4:15, Master = 7:00, Expert = 14:00

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

Today’s Surprise originated from an unintended mistake. Despite a puzzle labeled “Star Battle” and a graphic with a “2 star” label at the top, Friday’s puzzle was attempted by first one and then many solvers out of curiosity as a LITS. While I’ve seen a Star Battle that can double as a LITS, this was not originally one of them and it is not a typical property to have.

Undaunted by the challenge, Tapio Saarinen (ArDeeJ) sent along a modification of my puzzle into a LITS. After some tweaks by me, we have a Christmas Tree LITS puzzle with very few changes from the original (see this crude sketch). Enjoy the gift that keeps on giving!

PDF

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

Theme: Christmas Tree LI(gh)TS

Rules: Standard LITS rules.

Or, if you prefer to treat this as a Star Battle for some unknown reason, use these rules: In this variation of Star Battle, place the indicated number of stars in each row, column, and region. Then shade exactly four connected cells (without stars) in each outlined region, to form an L, I, T, or S tetromino, so that the following conditions are true: (1) All shaded cells are connected with each other; (2) No 2×2 group of cells can be entirely shaded black; (3) When two tetrominoes in adjacent regions share an edge, they must not be of the same type (L, I, T, or S), regardless of rotations or reflections.

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 with a comma.

Solution: PDF

Editorial Note: “Double Word Puzzle Score?” Inspired to write his own letter pairs after solving Palmer’s (see previous post), Grant contributed this very fun submission which we are also publishing today for a rare double puzzle day.

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 to mark off the clues.)

Theme: Months

Rules: Place the 12 words into the grid, one letter per cell, so they can be read from left to right or from top to bottom, without crossing or overlapping each other. A dot between two cells indicates that both cells must contain the same letter. All possible dots are given. Or see this example from the WPC instructions.

Answer String: For each column from left to right, enter the number of unused cells in that column (eg “3510563449”).

Time Standards (highlight to view): Grandmaster = 2:30, Master = 4:00, Expert = 8:00

Solution: PDF

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 to mark off the clues.)

Theme: One-Point Letters

Rules: Place the 9 words into the grid, one letter per cell, so they can be read from left to right or from top to bottom, without crossing or overlapping each other. A dot between two cells indicates that both cells must contain the same letter. All possible dots are given. Or see this example from the WPC instructions.

Answer String: For each column from left to right, enter the number of unused cells in that column (eg “3510563449”).

Time Standards (highlight to view): Grandmaster = 1:30, Master = 4:30, Expert = 9:00

Solution: PDF