Archive for the ‘Variation’ Category:

Dr. Sudoku Prescribes #77 – Nurikabe (Unique Islands)

Nurikabe by Thomas Snyder

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

This is a “Twisted Tuesday” puzzle variation.

Theme: Unique Islands

Rules: Standard Nurikabe rules. Also, each island shape must be unique. This means that no two islands, including rotation and/or reflection of the shapes, can be superimposed.

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 = 4:15, Master = 6:00, Expert = 12:00

Solution: PDF

Sunday Surprise #2 – Dalek Invasion

This past week, another doctor made the mistake of appearing here. It seems trouble follows him everywhere, as puzzle creator Craig Kasper reveals here.

Sudoku Variation by Craig Kasper

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

Theme: Dalek Invasion

Rules: Standard Sudoku rules except that instead of the numbers 1-9 this puzzle uses the letters in “END MATRIX”. Also, clues in the grid represent typical “Seek and Spell/Kanaore” clues; specifically, it must be possible to read each of the words/phrases listed below the grid by starting at the indicated number, moving one cell in the direction indicated by the arrow, and then continuing to move one cell at a time up, down, left, or right to complete the word/phrase. No cell may be used more than once in a single path, but the same cell can appear in the paths of different words/phrases.

Answer String: Enter the 2nd row from left to right, followed by a comma, followed by the 6th row from left to right. Use all capital letters.

Solution: PDF

From the Foxger’s Den #14: Star Battle (Corrupted Regions)

Star Battle by Grant Fikes

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

This is a “Franken-Friday” puzzle variation.

Theme: Corrupted Regions

Rules: Variation of standard Star Battle rules. Two stars per row and column, but no region has exactly two stars. Each region must contain some number of stars other than 2, including possibly no stars at all.

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 = 2:30, Master = 4:30, Expert = 9:00

Solution: PDF

From the Foxger’s Den #13: Sudoku (Seek and Spell)

Sudoku Variation by Grant Fikes

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

This is a “Twisted Tuesday” puzzle variation.

Theme: Doctor Sudo-Who?

Rules: Standard Sudoku rules except that instead of the numbers 1-9 this puzzle uses the letters in “WORD BATCH”. Also, clues in the grid represent typical “Seek and Spell/Kanaore” clues; specifically, it must be possible to read each of the words/phrases listed below the grid by starting at the indicated number, moving one cell in the direction indicated by the arrow, and then continuing to move one cell at a time up, down, left, or right to complete the word/phrase. No cell may be used more than once in a single path, but the same cell can appear in the paths of different words/phrases.

Answer String: Enter the 1st column from top to bottom, followed by a comma, followed by the 5th column from top to bottom. Use all capital letters.

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

Solution: PDF

Dr. Sudoku Prescribes #71 – Cave (Product)

Cave by Thomas Snyder

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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)

This is a “Franken-Friday” puzzle variation.

Theme: Common Products

Rules: Variation of Cave rules. Each clue represents the product of the # of row cells visible (including the cell itself) with the # of column cells visible (including the cell itself).

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 = 3:00, Master = 4:45, Expert = 9:30

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.

Dr. Sudoku Prescribes #69 – Skyscrapers (Sum)

Sum Skyscrapers by Thomas Snyder

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

This is a “Twisted Tuesday” puzzle variation.

Theme: Arithmetic Series

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 3rd row from left to right, followed by a comma, followed by the 5th row from left to right.

Time Standards (highlight to view): Grandmaster = 1:30, Master = 2:45, Expert = 5:30

Solution: PDF

Dr. Sudoku Prescribes #66 – Tapa (Pentomino)

Tapa by Thomas Snyder

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.)

This is a “Franken-Friday” puzzle variation.

Theme: Pentapa

Rules: Standard Tapa rules. Also, the Tapa wall in this puzzle is made using one of each pentomino given below the grid with no overlaps. Rotations and reflections are allowed. (Note: There is no P pentomino here because it would violate Tapa rules).

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 = 6:30, Master = 11:00, Expert = 22:00

Solution: PDF

From the Foxger’s Den #9: Slitherlink (Domino)

Slitherlink by Grant Fikes

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

This is a “Twisted Tuesday” puzzle variation.

Theme: Double Domino – both domino-based clue groupings, and a domino-based loop.

Rules: Standard Slitherlink rules; also, the interior of the loop must be divisible into dominoes (1×2 rectangles) in at least one way without any overlaps.

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 = 4:30, Master = 7:00, Expert = 14:00

Editorial Note: This puzzle is a fair bit more difficult than our usual Tuesday puzzles, but this may be a side effect of the new Twisted Tuesday format.

Solution: PDF

Dr. Sudoku Prescribes #62 – Sudoku (Seek and Spell)

Sudoku Variation by Thomas Snyder

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

This is a “Franken-Friday” puzzle variation.

Theme: Mostly Themeless! – Besides elements of symmetry and some patterning in the numbers, the design is focused on the logical solution path.

Rules: Standard Sudoku rules. Clues in the grid represent typical “Seek and Spell/Kanaore” clues; specifically, it must be possible to read each of the numbers listed below the grid by starting at the indicated letter, moving one cell in the direction indicated by the arrow, and then continuing to move one cell at a time up, down, left, or right to complete the number. No cell may be used more than once in a single number’s path, but the same cell can appear in the paths of different numbers.

Answer String: Enter the 3rd column from top to bottom, followed by a comma, followed by the 9th column from top to bottom.

Time Standards (highlight to view): Grandmaster = 7:00, Master = 12:30, Expert = 25:00

Solution: PDF

From the Foxger’s Den #7: Battleships (Yajilin)

Battleships (Yajilin) by Grant Fikes

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between Battleships placement and line drawing modes.)

This is a “Twisted Tuesday” puzzle variation.

Theme: A Fleet of Clues

Rules: Variation of Battleships rules. Place the fleet of ships in the grid so that no ships touch each other, even diagonally. The grid contains internal clues (a number and an arrow) that show how many ship segments are in the indicated direction. All remaining cells containing neither a ship nor a clue must be able to form a single loop, as in a Yajilin puzzle (see for example here but note the “black square rules” are replaced with battleships placement rules).

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.

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

Solution: PDF