Archive for the ‘Surprise Puzzles’ Category:

Sunday Surprise: 100th Puzzle Spectacular by Prasanna Seshadri

100th Puzzle Spectacular by Prasanna Seshadri

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

Light and Shadow: Divide the grid into shaded and unshaded regions, each containing exactly one number and with an area equal to that number. Numbers in white cells are part of white regions; numbers in shaded cells are part of shaded regions. Same colored regions cannot share an edge.

Nurikabe: Shade some empty cells black so that the grid is divided into white areas, each containing exactly one number and with the same area in cells as that number. Two white areas may only touch diagonally. All black cells must be connected with each other, but no 2×2 group of cells can be entirely shaded black.

Kurotto: Shade some cells so that each circled number represents the total count of shaded cells in connected groups sharing an edge with that number. Cells with circles cannot be shaded.

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

Sunday Surprise #13 – Gapped Kakuro by Serkan Yürekli

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.

Gapped Kakuro by Serkan Yürekli

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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

Note: Follow this link for other Kakuro puzzles.

Sunday Surprise #12 – Palimpsest Puzzle Set by Nikolai Beluhov

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).



Fillomino by Nikolai Beluhov


Slitherlink by Nikolai Beluhov


Tapa by Nikolai Beluhov

Simple Loop

Fillomino by Nikolai Beluhov

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.

Sunday Surprise #11 – Basement Skyscraper Sudoku

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.

Basement Skyscraper Sudoku by Hans van Stippent


Theme: New Variation/Logic

Rules: Standard Sudoku rules. Also, standard Skyscrapers rules. Additionally, the cells in grey 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.

Sunday Surprise #10 – Christmas Tree LI(gh)TS

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!

LITS by Tapio Saarinen and Thomas Snyder


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.

Sunday Surprise #9 – Matryoshka Fillomino

Today’s surprise comes from Nikolai Beluhov, a graduate student of mathematical logic who has been sharing some creative puzzle ideas with me recently. Some of them have ended up on his new puzzle blog Puzzled By Titles. This puzzle has become a Sunday Surprise.

Much like a set of Matryoshka dolls, this Fillomino is a puzzle with many layers. Remove the outer border and a new valid Fillomino arises. Keep doing this all the way down to the very center where a 2×2 puzzle awaits. The layers have a wide variety of difficulty and required logical strategies. Can you solve them all?

Fillomino by Nikolai Beluhov


Theme: Matryoshka (nesting property) across 5 puzzles.

Rules: Standard Fillomino rules.

Answer String: For each puzzle from largest (10×10) to smallest (2×2), enter the numbers placed in each cell along the upper-left to lower-right diagonal in order. Separate each puzzle’s entry by a comma (Your answer will be of the form AAAAAAAAAA,BBBBBBBB,CCCCCC,DDDD,EE).

Sunday Surprise #8 – Mystery Tapa

Today’s surprise originally comes from Hans van Stippent, with some edits by me (Thomas Snyder) to increase the challenge and rewards of the solve. Together, we present this creative “Mystery Tapa” where all the clues (any value from 1-8) have been replaced with ?’s.

Tapa by Hans van Stippent and Thomas Snyder


Theme: Clueless?

Rules: Variation of Tapa rules. All clue numbers (1 and above) have been replaced with question marks.

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 entry from the next with a comma. A double-digit number should have both digits entered.