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)

Theme: Logical

Rules: Standard LITS 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 = 5:00, Master = 7:30, Expert = 15:00

Solution: PDF

PDF

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

Theme: Frame

Rules: Standard LITS 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 = 3:30, Master = 6:00, Expert = 12:00

Solution: PDF

PDF

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

Theme: None?

Rules: Standard LITS 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 = 2:00, Master = 2:30, Expert = 5:00

Solution: PDF

PDF

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

Theme: Logical; after solving: did you notice that starting in the upper-left corner you can fill in all the tetrominoes in L-I-T-S-L-I-T-S-L-… order?

Rules: Standard LITS 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 = 1:30, Master = 2:00, Expert = 4:00

Solution: PDF

Editor’s Note: Welcome to “LITS Week” where we will introduce another puzzle style to Grandmaster Puzzles’ repertoire. Please check out our Rules and Info page for LITS, including a new example puzzle, if you are not familiar with the type.