This week we are sharing easy sample puzzles from our ebook The Puzzlemasters’ Workshop which showcases six authors exploring new puzzle styles or variations with 8-10 challenges in each section. Today’s post is Inverse LITS.

PDF

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

Theme: Rectangles

Background: Variation of the shading puzzle LITS, where the usual rules related to shaded tetrominoes in each region are inverted to apply to unshaded tetrominoes in each region. First explored by Bram de Laat in 2012, and now more fully explored by Chris Green.

Rules: Shade some cells black so that in each region there are exactly four unshaded cells that form an L, I, T, S, or O tetromino. When two unshaded tetrominoes share an edge across regions, they must not be the same shape regardless of rotations or reflections. All shaded cells must be connected into a single group, but no 2×2 group of cells can be entirely shaded black.

Example by Thomas Snyder:

(No official times or solution entry for this week; just click “SOLVE?” when finished.)

Solution: Last page of PDF

Note: More Inverse LITS puzzles can be found in The Puzzlemasters’ Workshop.

Our master+ subscribers receive access to two bonus puzzles each week in addition to other rewards. We make these posts so those supporters have a space to comment on these puzzles, mark as FAVES, or log their solving. If you are interested in subscribing and seeing these bonus puzzles, click here for more info.

Theme: Clue Symmetry and Logic

Author/Opus: This is the 310th puzzle from our contributing puzzlemaster Grant Fikes.

Rules: Standard Cave rules.

Answer String: Enter the length in cells of each of the cave segments from top to bottom for the marked columns, starting at the left. Separate each column’s entry with a comma.

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

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. More Cave puzzles can be found in Roger Barkan’s Colossal Cave Collection, in The Art of Puzzles, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

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: Clue Symmetry and Logic

Author/Opus: This is the 264th puzzle from our contributing puzzlemaster Serkan Yürekli.

Rules: Standard Cave rules. (The puzzle is on a hexagonal grid and cells now see in a maximum of six possible directions.)

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 = 4:45, Master = 6:45, Expert = 13:30

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. More Cave puzzles can be found in Roger Barkan’s Colossal Cave Collection, in The Art of Puzzles, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

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: Snowflake

Author/Opus: This is the 16th puzzle from guest contributor Ashish Kumar.

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 Standards (highlight to view): Grandmaster = 3:15, Master = 6:15, Expert = 12:30

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. More Cave puzzles can be found in Roger Barkan’s Colossal Cave Collection, in The Art of Puzzles, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

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: Runaway

Author/Opus: This is the 3rd puzzle from guest contributor Michael Tang.

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 Standards (highlight to view): Grandmaster = 3:00, Master = 5:00, Expert = 10:00

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. More Cave puzzles can be found in Roger Barkan’s Colossal Cave Collection, in The Art of Puzzles, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

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: Easy as 1 2 3 4 … 11

Author/Opus: This is the 144th puzzle from our contributing puzzlemaster Grant Murat Can Tonta.

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 Standards (highlight to view): Grandmaster = 2:15, Master = 4:00, Expert = 8:00

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. More Cave puzzles can be found in Roger Barkan’s Colossal Cave Collection, in The Art of Puzzles, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

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: Diagonals

Author/Opus: This is the 309th puzzle from our contributing puzzlemaster Grant Fikes.

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 Standards (highlight to view): Grandmaster = 1:50, Master = 3:00, Expert = 6:00

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. More Cave puzzles can be found in Roger Barkan’s Colossal Cave Collection, in The Art of Puzzles, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

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: Clue Groups

Author/Opus: This is the 341st puzzle from Thomas Snyder, aka Dr. Sudoku.

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 Standards (highlight to view): Grandmaster = 1:30, Master = 1:45, Expert = 3:30

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. More Cave puzzles can be found in Roger Barkan’s Colossal Cave Collection, in The Art of Puzzles, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

Our master+ subscribers receive access to two bonus puzzles each week in addition to other rewards. We make these posts so those supporters have a space to comment on these puzzles, mark as FAVES, or log their solving. If you are interested in subscribing and seeing these bonus puzzles, click here for more info.

Theme: 2, 4, 6, 8, 10

Author/Opus: This is the 143rd puzzle from our contributing puzzlemaster Murat Can Tonta.

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 Standards (highlight to view): Grandmaster = 1:50, Master = 2:30, Expert = 5:00

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. More Cave puzzles can be found in Roger Barkan’s Colossal Cave Collection, in The Art of Puzzles, and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

Our master+ subscribers receive access to two bonus puzzles each week in addition to other rewards. We make these posts so those supporters have a space to comment on these puzzles, mark as FAVES, or log their solving. If you are interested in subscribing and seeing these bonus puzzles, click here for more info.

Theme: Logical

Author/Opus: This is the 308th puzzle from our contributing puzzlemaster Grant Fikes.

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 = 2:15, Master = 6:00, Expert = 12:00.

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