PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between number entry and shading modes.)

Theme: WPC Practice

Rules: Enter digits 1 through 4 into some cells so that each row and column contains each digit exactly once. Also, along the snail (from the upper-left corner and spiraling to the center) digits must occur in 1-2-3-4-1-2-3-4-… order. Some clues are given in the grid in the form of lit digital segments. Each of these cells must contain a digit, and that digit must have that segment lit in the form shown below the puzzle.

Or see an example from the WPC instructions using 1 to 3 here.

Answer String: Enter the marked rows from left to right, separating the two rows by a comma. Use an X (capital letter) for each empty square.

Time Standards (highlight to view): Grandmaster = 6:00, Master = 8:30, Expert = 17:00

Solution: PDF

PDF

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

Theme: It’s Sudoku Time

Rules: Standard Arrow Sudoku rules.

Answer String: Enter the 4th row from left to right, followed by a comma, followed by the 8th row from left to right.

Time Standards (highlight to view): Grandmaster = 4:30, Master = 6:45, Expert = 13:30

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.

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)

Theme: Anti-Symmetry

Rules: Standard Masyu rules.

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 = 2:00, Master = 3:30, Expert = 7:00

Solution: PDF

PDF

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

Theme: Logical

Rules: Standard Cross the Streams rules.

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 = 2:30, Master = 3:45, Expert = 7:30

Solution: PDF

PDF

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

Theme: Double

Rules: Standard TomTom rules, using digits from 1-5.

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

Time Standards (highlight to view): Grandmaster = 1:15, Master = 2:00, Expert = 4:00

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.

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

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between Number entry mode and a shading mode to help track complete clues.)

Theme: Clue Symmetry, and Very Hard WPC Practice

Rules: Variation of Sudoku. Place integers from -4 to 4 into each cell so that each row, column, and region contains each integer from -4 to 4 exactly once. The numbers outside the grid represent the sum of all integers between that clue and the zero in that row/column. Some cells inside the grid already contain an integer but no sign is given. It is part of the puzzle to determine if these values are positive or negative. An example using -2 to 2 from the WPC instructions is here.

Answer String: Enter the numbers (ignoring sign) from left to right in the marked rows, separating each row with a comma (eg “123401234,431023412”).

Time Standards (highlight to view): Grandmaster = 10:00, Master = 16:00, Expert = 32:00

Solution: PDF

PDF

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

Theme: “The Star Battle for Christmas”

Rules: Standard Star Battle rules. Two stars per row, column, and region. Note: the shading is just to emphasize the theme and is not involved in the solve.

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 = 2:15, Master = 5:15, Expert = 10:30

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.

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 on edges)

Theme: Clue Symmetry and Logic

Rules: In this variation of Tapa, the wall is in the form of a single non-intersecting loop. Clues inside the grid represent the number of neighboring cells visited by the loop; if there is more than one number in a cell, each number should be represented with a separate loop segment. There is no 2×2 rule of Tapa in this puzzle. This example image should help:

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. Separate each row’s entry with a comma. For the example, this would be “11,12”.

Time Standards (highlight to view): Grandmaster = 1:30, Master = 2:15, Expert = 4:30

Solution: PDF

Note: Follow this link for other Tapa-Like Loop puzzles. If you are new to this puzzle type, here are our easiest Tapa puzzles to get started on.

PDF

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

Theme: Nine High

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 2nd row from left to right, followed by a comma, followed by the 5th row from left to right.

Time Standards (highlight to view): Grandmaster = 1:00, Master = 2:15, Expert = 4:30

Solution: PDF