Quilt Block
This one is all about finding the break-in. It also appears in Indigestion Collection 2
Estimated difficulty: 3/5
Rules
Normal sudoku and killer cage rules apply. Every row, column, and box must contain a complete set of the digits 1-9.
Digits along arrows must sum to the value shown in the attached circle. Digits can repeat along arrows if allowed by other rules.
Dance with a Little Killer
For once, no fog and no killer cages! This puzzle also appears in Indigestion Collection 2.
Estimated difficulty: 2.5/5
Rules
Normal sudoku and killer cage rules apply. Every row, column, and box must contain a complete set of the digits 1-9.
Little killers: Numbers outside the grid give the sum of all digits along the indicated diagonal. Digits may repeat along the little killer diagonal if permitted by other rules.
Chase the Fog Away
Another Fog and Killer puzzle! This one also appears in GAS Collection 2.
Estimated difficulty: 1.5/5
Rules
Normal sudoku and killer cage rules apply. Every row, column, and box must contain a complete set of the digits 1-9.
Digits inside cages indicated by dashed lines cannot repeat and must sum to the value in the upper left corner of the cage, if given.
Fog initially covers part of the grid. Placing correct digits clears fog from surrounding cells, possibly revealing more clues. It is possible (even sometimes necessary) to place digits within the fog.
Adding to My Exes
We set this 6x6 as an introduction to the types of logic that are common to the X-sums constraint. It also appears in the Brassica Collection.
Estimated difficulty: Brassica
Rules
Normal 6x6 sudoku rules apply. Every row, column, and box must contain a complete set of the digits 1-6.
X-sums: values outside the grid give the sum of the first X digits seen along that row or column from the direction of the clue, where X is the digit in the cell closest to the clue.
Death by Smog
This puzzle also appears in GAS Collection 2.
Estimated difficulty: 1.5/5
Rules
Normal sudoku and killer cage rules apply. Every row, column, and box must contain a complete set of the digits 1-9. Digits inside cages indicated by dashed lines cannot repeat and must sum to the value in the upper left corner of the cage, if given. Fog initially covers part of the grid. Placing correct digits clears fog from surrounding cells, possibly revealing more clues.
Newgate Fog
We set this puzzle as an introductory fog puzzle for novice solvers. The name is a reference to Newgate Gaol in Britain in connection to the cages that appear through the grid. It was then featured by BremSter as Sudoku on a Cold Foggy Day for FullDeck's birthday on 23 November 2022. This puzzle also appears in GAS Collection 2.
Estimated difficulty: 1/5
Rules
Normal sudoku and killer cage rules apply. Every row, column, and box must contain a complete set of the digits 1-9. Digits inside cages indicated by dashed lines cannot repeat and must sum to the value in the upper left corner of the cage, if given. Fog initially covers part of the grid. Placing correct digits clears fog from surrounding cells, possibly revealing more clues.
Drunkard's Walk
Path construction, fog of war, and modular lines ... what a delicious combination! This puzzle was featured on Cracking the Cryptic as The Drunkard's Walk on 23 November 2022 and also appears in Indigestion Collection 2. It inspired this lovely limerick by Amos Wittenberg in the comments on the video, included here with permission from the author:
A drunkard whose brain lacked all clarity
Walked home with bizarre regularity.
It may sound impossible,
As the fog was an obstacle
But his path had perfect modularity!
Estimated difficulty: 2.5/5
Rules
After a night of celebrating, our hero leaves r1c1, through the fog, trying to get home to r9c9. With each step, they move to an orthogonally adjacent cell, forming a modular line as they go. (That means any set of three contiguous digits along their path must include one each from {147}, {258}, and {369}.)
They stagger from streetlamp to streetlamp as they go, each represented by a yellow disk in a cell. Some of the streetlamps are visible from the start but others are hidden by the fog and will only be revealed when correct digits are placed nearby. Their path must lead them to every streetlamp. All streetlamps are from the same modular set and whenever a number from that set is on the path, it appears as a streetlamp. Numbers from that modular set which are not on the path are not streetlamps.
If our hero enters a killer cage, they must completely traverse the cage before exiting it. Some killer cages may be avoided entirely.
Normal sudoku and killer cage rules apply. Every row, column, and box must contain a complete set of the digits 1-9. Digits inside cages indicated by dashed lines cannot repeat and must sum to the value in the upper left corner of the cage, if given.
Weathervane
This puzzle was set while students in our Puzzles and Paradoxes class were setting their first 6x6 puzzles. It also appears in GAS Collection 2.
Estimated difficulty: GAS
Rules
Standard 6x6 sudoku rules apply: every row, column, and 2x3 box indicated by darker shaded lines must contain a complete set of the digits 1-6.
Arrows: Digits along an arrow must sum to the value shown in the attached circle. Digits may repeat along the arrow if allowed by other rules.
Foglet
This puzzle was set while students in our Puzzles and Paradoxes class were setting their first 4x4 puzzles. We used the same constraints of killer cages but also allowed ourselves to have fun with Fog of War.
Estimated difficulty: Brassica
Rules
Standard 4x4 sudoku rules apply: every row, column, and 2x2 box indicated by darker shaded lines must contain a complete set of the digits 1-4.
Killer cages: digits inside cages marked by dashed lines cannot repeat and must sum to the number shown in the top left corner of the cage.
Fog: Part of the grid is covered with fog. As correct digits are placed, the fog will clear from cells surrounding the correct digit, revealing additional clues. There is always enough information in the revealed portion of the grid to place another correct digit. Digits can be placed within the fog.