Dr. Sudoku Prescribes #21 – Cave

Cave by Thomas Snyder

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: “23” – Both today’s date, and a fine number for themed logic puzzles, such as the Map Puzzles from Bang 23.

Rules: Standard Cave rules.

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 Standard: Cave Master = 3:00, Expert = 9:00, Novice = 30:00

Note: Advice on solving this puzzle (and Cave puzzles in general) has now been posted in “Ask Dr. Sudoku #4

Solution: PDF

Note: Follow this link for other Cave variations and 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 #20 – Arrow Sudoku

Arrow Sudoku by Thomas Snyder

PDF

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

Theme: Diagonals (two more than yesterday!)

Rules: Standard Arrow Sudoku rules. Range is 1-6.

Answer String: Enter the 2nd column from top to bottom, followed by a comma, followed by the 4th column from top to bottom.

Time Standard: Arrow Sudoku Master = 1:00, Expert = 3:00, Novice = 10:00

Solution: PDF

Note: Follow this link for more Arrow Sudoku. If you are new to this puzzle type, here are our easiest Arrow Sudoku to get started on. More Arrow Sudoku puzzles can be found in The Art of Sudoku 2.

Dr. Sudoku Prescribes #19 – Cave

Cave by Thomas Snyder

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: Ascending/Descending Diagonal

Rules: Standard Cave rules.

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 Standard: Cave Master = 1:00, Expert = 3:00, Novice = 10:00

Solution: PDF

Note: Follow this link for other Cave variations and 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 #18 – Star Battle

Star Battle by Thomas Snyder

PDF

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

Theme: Boxed In (but it plays out differently than yesterday’s “Boxed In”)

Rules: Standard Star Battle rules. Two stars per row, column, and region.

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 Standard: Star Battle Master = 9:00, Expert = 27:00, Novice = 1:30:00

Solution: PDF and solving video.

Editorial Note 1: Be warned — this puzzle is difficult and has inconsistent and highly variable solving times, possibly because it may require some unusual techniques. Advice on solving this puzzle has now been posted in “Ask Dr. Sudoku #3

Note 2: 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.

Dr. Sudoku Prescribes #17 – Thermo-Sudoku

Thermo-Sudoku by Thomas Snyder

PDF

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

Theme: Boxed In

Rules: Standard Thermo-Sudoku rules. Range is 1-9.

Answer String: Enter the 9th row from left to right, followed by a comma, followed by the 5th column from top to bottom.

Time Standard: Thermo-Sudoku Master = 5:00, Expert = 15:00, Novice = 50:00

Solution: PDF and solving video.

Note: Follow this link for more Thermo-Sudoku puzzles. If you are new to this puzzle type, here are our easiest Thermo-Sudoku to get started on. More Thermo-Sudoku puzzles can be found in The Art of Sudoku 2.

Dr. Sudoku Prescribes #16 – Star Battle

Star Battle by Thomas Snyder

PDF

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

Theme: Crossed Crosses

Rules: Standard Star Battle rules. Two stars per row, column, and region.

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 Standard: Star Battle Master = 2:00, Expert = 6:00, Novice = 20:00

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.

Dr. Sudoku Prescribes #15 – Thermo-Sudoku

Thermo-Sudoku by Thomas Snyder

PDF

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

Theme: Double Zeroes

Rules: Standard Thermo-Sudoku rules. Range is 1-9.

Answer String: Enter the 9th row from left to right, followed by a comma, followed by the 5th column from top to bottom.

Time Standard: Thermo-Sudoku Master = 2:15, Expert = 6:45, Novice = 22:30

Solution: PDF

Note: Follow this link for more Thermo-Sudoku puzzles. If you are new to this puzzle type, here are our easiest Thermo-Sudoku to get started on. More Thermo-Sudoku puzzles can be found in The Art of Sudoku 2.

Dr. Sudoku Prescribes #14 – Star Battle

Star Battle by Thomas Snyder

PDF

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

Theme: Downward Spiral

Rules: Standard Star Battle rules. One star per row, column, and region.

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 Standard: Star Battle Master = 0:45, Expert = 2:15, Novice = 7:30

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.

Dr. Sudoku Prescribes #13 – Thermo-Sudoku

Thermo-Sudoku (1-6) by Thomas Snyder

PDF

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

Theme: Grandmaster Puzzles (the G and P shapes in the corners)

Rules: Standard Thermo-Sudoku rules. Range is 1-6.

Answer String: Enter the 5th row from left to right, followed by a comma, followed by the 4th column from top to bottom.

Time Standard: Thermo-Sudoku Master = 0:45, Expert = 2:15, Novice = 7:30

Solution: PDF

Note: Follow this link for more Thermo-Sudoku puzzles. If you are new to this puzzle type, here are our easiest Thermo-Sudoku to get started on. More Thermo-Sudoku puzzles can be found in The Art of Sudoku 2.

Dr. Sudoku Prescribes #12 – Tight Fit Sudoku

Tight Fit Sudoku (1-11) by Thomas Snyder

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between Sudoku = big entries and Number candidate = small entries in the corners of cells.)

Theme: The patterned digits in this Tight Fit Sudoku set up an interesting logical solve.

Rules: Standard Tight Fit Sudoku rules. Range is 1-11.

Answer String: Enter the 3rd column from top to bottom, followed by a comma, followed by the 5th column from top to bottom. Type both digits of the two-digit numbers 10 and 11. (Note: for the tight fit cells, enter the top before the bottom as would be normal for the read order.)

Time Standard: TFSudoku Master = 4:45, Expert = 14:15, Novice = 47:30

Solution: PDF and solving video.

Note: Follow this link for other Tight Fit Sudoku puzzles on this website. If you are new to this puzzle type, here are our easiest Tight Fit Sudoku to get started on. More Tight Fit Sudoku can be found in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli and in The Art of Sudoku 2.