PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between ship placement and shading modes. In ship placement mode, right click gives sea, left click gives circle/square, left click and drag for rounded ships.)

This is a “Franken-Friday” puzzle variation.

Theme: Squares of Squares

Rules: Standard Battleships rules. The fleet in this puzzle has no rounded ends; instead, all ship segments are square and indistinguishable.

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 = 3:30, Master = 5:45, Expert = 11:30

Solution: PDF

PDF

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

This is a “Twisted Tuesday” puzzle variation.

Theme: Inverted Clues

Rules: Variation of Cross the Streams rules. The clues in this puzzle are inverted. They indicate the WHITE (unshaded) areas, not the black areas as in other Cross the Streams. The shaded cells must still obey the regular rules (connectivity, no 2×2 squares).

Answer String: Enter the length in cells of each of the black segments from top to bottom for the marked columns, going in order from A to B to C to D and separating each entry with a comma.

Time Standards (highlight to view): Grandmaster = 2:15, Master = 3:30, Expert = 7:00

Solution: PDF

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)

This is a “Franken-Friday” puzzle variation.

Theme: Prime Time

Rules: Standard Cave rules, except the grid is hexagonal.

Answer String: Enter the length in cells of each of the internal cave 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 = 6:00, Master = 8:30, Expert = 17:00

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.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between “big” sudoku and “small” number entry modes.)

This is a “Twisted Tuesday” puzzle variation.

Theme: Cage symmetry and repeated clue values

Rules: Variation of standard TomTom rules. The indicated range [1-6] is larger than usual for a 4 x 4 puzzle. Some cells containing slashes require two digits to be placed. These cells should be treated as fractional values (top value over bottom value) for the purposes of solving the puzzle.

Answer String: Enter the 3rd row from left to right, followed by a comma, followed by the 4th row from left to right. (Note: for the cells with slashes, enter the top before the bottom.)

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

Solution: PDF

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

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)

This is a “Franken-Friday” puzzle variation.

Theme: Half Truths

Rules: Variation of Masyu rules. Half of the circles are lying; a lying white circle is actually a black circle and a lying black circle is actually a white circle. The loop must alternate between true circles and lying circles (T-L-T-L-…).

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 5:30, Master = 10:00, Expert = 20:00

Solution: PDF

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: Visual and logical

Rules: Variation of standard Fillomino rules. All polyominoes of same size besides 4 cannot touch. But all tetrominoes — polyominoes of size 4 — must be connected as in a LITS puzzle. All “4” clues have been replaced by letters indicating which tetromino type they belong to.

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 6th row, followed by a comma, followed by the 14th row.

Time Standards (highlight to view): Grandmaster = 7:00, Master = 10:30, Expert = 21:00

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 alternate between a Shading mode and a composite Yajilin 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.)

This is a “Franken-Friday” puzzle variation.

Theme: Mostly logical; after solving, did you notice the message in the top few rows?

Rules: Standard Cross the Streams rules. Also, the shaded region must be able to be split into tetrominoes to form a valid LITS solution.

Answer String: Enter the length in cells of each of the black segments from top to bottom for the marked columns, going in order from A to B to C to D and separating each entry with a comma.

Time Standards (highlight to view): Grandmaster = 4:00, Master = 7:30, Expert = 15:00

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)

This is a bonus “Twisted Tuesday” puzzle variation.

Theme: None?

Rules: Standard Double Back rules (originally from MellowMelon). In short: draw a single loop that enters and exits every cell exactly once, and enters and exits every region exactly twice.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 2:15, Master = 3:30, Expert = 7:00

Solution: PDF

As promised, here was the original Thermo-Skyscrapers created for the USPC. I like the visual pattern and tightness of solving path much more, but it was simply too hard to use, particularly before the practice you now have from the one you saw on the USPC from yesterday’s post.

PDF

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

Theme: No given numbers, and full clue cell symmetry

Rules: Standard Skyscrapers rules. Also, as in Thermo-Sudoku, digits must be strictly increasing in all thermometer shapes from round bulb to flat end.

Answer String: Enter the seven digits inside the grid for the 7th row from left to right, followed by a comma, and then the seven digits inside the grid for the 4th column from top to bottom.

Solution: PDF

The hardest puzzle I wrote for the USPC was originally intended to be presented as a subtle “surprise”. The rules would have covered what thermometer shapes do (strictly increase from bulb to flat end), but would not have been explicit that those shapes could reach outside the grid. So finding a grid with no external numbers but with many external shapes would have been a manageable but perhaps unexpected surprise. But it was decided to just be explicit here, and with some other authors in the last few months having used the same external clue ideas with skyscrapers (including myself here with an Even/Odd Skyscrapers after I knew the fate of this puzzle) it’s not clear if this would have been unexpected anyway.

I thought this was an interesting extension of some inequality skyscraper concepts I’ve seen elsewhere. My first attempt at this puzzle type was judged very elegant and far too hard. My second attempt kept one of these two traits and made it onto the test. Like the TomTom, this variation seemed to get pretty good reviews, but I do know some solvers who fell into the trap of thinking an outside number blocked that number from appearing inside the grid.

PDF

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

Theme: No given numbers, and full clue cell symmetry

Rules: Standard Skyscrapers rules. Also, as in Thermo-Sudoku, digits must be strictly increasing in all thermometer shapes from round bulb to flat end.

Answer String: For the USPC, the answer string was the internal cells in the 4th row and 7th row. For this week, you can just hit the solved button on an honor system if you think you’ve solved it.

Solution: PDF