Losing Our Religion
Straightforward scanning and killer cage practice. This puzzle also appears in our GAS Collection. The title is a nod to the fact that none of our threes in the corner ever get a song from Simon Anthony.
Estimated difficulty: 1.5/5
Rules
Normal sudoku rules apply: every row, column, and box contains a complete set of the digits 1-9.
Killer cages: digits inside cages marked by dashed lines cannot repeat and must sum to the value shown in the upper left corner of the cage.
Solve in the Sudokupad app with solution checker
Point Break
Straightforward scanning and killer cage practice.
Estimated difficulty: 1.5/5
Rules
Normal sudoku rules apply: every row, column, and box contains a complete set of the digits 1-9.
Killer cages: digits inside cages marked by dashed lines cannot repeat and must sum to the value shown in the upper left corner of the cage.
Solve in the Sudokupad app with solution checker
Restricted Skylines
This puzzle arose from finding different constraints that produce strong patterns in the entire grid. It was featured by BremSter Puzzles on 27 September 2022. It also appears in our GAS Collection.
Estimated difficulty: 1.5/5
Rules
Normal sudoku rules apply: every row, column, and box contains a complete set of the digits 1-9.
Killer cages: digits inside cages marked by dashed lines cannot repeat and must sum to the value shown in the upper left corner of the cage.
Each digit in the grid is a "skyscraper" whose height is the digit in that cell. Taller skyscrapers obscure the view of smaller ones. Clues outside the grid tell how many skyscrapers are visible looking across the row or column from the direction of the clue.
Isotropic groups: Each group of nine cells occupying the same relative position in the nine boxes is isotropic: all nine are from {123} or all nine are from {456} or all nine are from {789}.
Box Twist
This puzzle serves as a gentle introduction to how the modular lines and killer cage logic interact. It originally appeared as "Full o'Beans, Missing Broccoli" in the Caging Constraints puzzle pack by BremSter.
Estimated difficulty: 1.5/5
Rules
Normal sudoku rules apply: every row, column, and box must contain a complete set of the digits 1-9.
Normal killer sudoku rules apply: digits inside a cage marked by dashed lines cannot repeat and must sum to the number shown in the upper left corner.
Modular lines: every set of three sequential digits along a line must contain a complete set of residues modulo 3, i.e. one digit from {1,4,7}, one from {2,5,8}, and one from {3,6,9}. Digits may repeat on a line if allowed by other rules.
Humidity
It's not the heat ...
This puzzle was first published to the July 2022 monthly puzzle prompt on the CTC Discord server for the weather and meteorology prompt.
Estimated difficulty: 1.5/5
Rules
Standard sudoku constraints: each row, column, and box must contain a complete set of the digits 1-9. Standard thermometer constraint: digits on thermometers must increase from bulb to tip.
So Much Negativity
A slow GAS puzzle.
Normal sudoku rules apply: every row, column, and box must contain a complete set of the digits 1-9.
XV: Digits separated by a V sum to 5. Digits separated by an X sum to 10. All possible Xs and Vs are given. (Negative constraint applies.)
An Easy Day's Knight
Our first puzzle of August 2022! We are very happy to have had this puzzle featured on two different channels: by BremSter on 7 October 2022 and by Sudoku Sauce on 9 October 2022.
Estimated difficulty: 1.5/5
Rules
Normal sudoku rules apply: every row, column, and box must contain a complete set of the digits 1-9.
Anti-knight constraint: Cells a chess knight's move apart cannot contain the same digit.
Leftovers Can Be Deadly
An easier modular lines puzzle that is perhaps just slightly above GAS difficulty. The "leftovers" refers to the uses of modularity, which is all about remainders. The "deadly" refers to the killer cages in the puzzle.
Estimated difficulty: 1.5/5
Rules
Normal sudoku rules apply: every row, column, and box must contain a complete set of the digits 1-9.
Modular lines: every set of three sequential digits along a modular line must contain a complete set of residues modulo 3, i.e. one digit from {1,4,7}, one from {2,5,8}, and one from {3,6,9}.
Killer cages: Digits in cages marked by dashed lines cannot repeat and must sum to the total shown in the upper left corner of the cage.
Isobars
Isobars was set in response to the July 2022 monthly puzzle prompt on the CtC Discord server: puzzles related to weather and meteorology. Isobars are lines of constant or equal pressure on a weather map.
Estimated difficulty: 1.5/5 (GAS-level)
Rules
Normal sudoku constraints: every row, column, and box must contain a complete set of the digits 1-9. Kropki pairs: cells separated by a white dot form a consecutive pair. Not all possible dots are given. Isobars (blue lines) have the same pressure along the entire line: either all the digits are low {1,2,3}, all the digits are middle {4, 5, 6} or all the digits are high {7, 8, 9}.
OGP
This puzzle also appears in the GAS Collection.
Estimated difficulty: 1.5/5
Rules
Standard sudoku constraints: each row, column, and box must contain a complete set of the digits 1-9.
Quadruples: Digits inside large circles must appear in one of the four cells surrounding the circle.
Down the Drain
As with the Brassica-level Dance Around the Maypole (February 2022), we recommend you start at the upper left corner and spiral your way inwards to the center.
Estimated difficulty: 2/5
Rules
Standard sudoku rules apply. Within cages, digits cannot repeat and must sum to the number shown in the upper left corner.
Nice Hot Cuppa
With snow in the forecast, let's settle in with a nice hot cuppa! This was our second puzzle posted for the CTC monthly puzzle prompt in January 2022: food and cuisine.
Estimated difficulty: 2/5
Rules
Standard sudoku rules apply. Digits along each gray line read the same forwards as backwards along the line. Digits can repeat along palindromes provided they follow normal sudoku constraints (standard palindrome rules). Digits shown within a circle must appear in one of the four cells adjacent to the circle (standard quadruple rules).
Driving Me Dotty
This puzzle, part of our Brassica-to-Gas series, has earned many reactions of "great puzzle" from the CTC Discord community. An easier version can be found in the Brassica Collection.
Estimated difficulty: 2/5
Rules
Normal sudoku rules and standard Kropki dots apply. (Digits separated by a white dot differ by 1. If two digits are separated by a black dot, then one is twice the other.) Not all possible dots are shown.
Category 6: Eye of the Storm
This puzzle has some nice early logic to resolve the long dot chains. It has earned many reactions of "great puzzle" from the CTC Discord community. Part of the Brassica-to-GAS series, an easier version can be found in the Brassica Collection.
Estimated difficulty: 2.5/5
Rules
Normal sudoku rules and standard Kropki dots apply. (Digits separated by a white dot differ by 1. If two digits are separated by a black dot, then one is twice the other.)
Salt and Pepper
We set this puzzle as our first response to the CTC Discord monthly puzzle prompt for January 2022: puzzles related to food and cuisine. It has earned many reactions of "great puzzle" and "beautiful theme" from the CTC Discord community. It also has enough solves (>150) and a sufficiently high beauty rating on LMD to have been placed in the LMD "often solved and nice" list, gaining it a place in our showcase.
Estimated difficulty: 2/5
Rules
The salt shaker on the upper left is a Renban line consisting of a set of consecutive digits in any order. The pepper shaker on the upper right is a German whispers line with each cell differing by at least five from neighboring cells along the line. Digits cannot repeat along the salt shaker or along the pepper shaker. The digits in the large circles at the tips of the shakers must appear in the four surrounding cells.
The numbers in the salt grains (white Kropki dots) tell the difference between the cells they join. The numbers in the pepper flakes (black Kropki dots) tell the ratio between the two cells they join.
Melting Gummy Worms
This puzzle focuses on thermo logic and elimination using locked sets for someone who has started to become comfortable with Kropki dot logic.
Estimated difficulty: 1/5
Rules
Normal sudoku rules apply. White dots mark pairs of consecutive digits. Not every pair of consecutive digits is marked with a white dot.
Now, what about those gummy worms? Those are actually thermometers, and as with any thermometer, the further you go from bulb to tip the higher the digit. Digits on thermometers do not have to be consecutive but could be.
Chivalry
This puzzle was set to explore anti-knight constraints. Although it's a nice little puzzle, there are other paths through it besides leveraging the full power of knight moves and it is only moderately difficult. It led to the much nicer Twelfth Knight (in the Indigestion Collection).
Estimated difficulty: 2/5
Rules
Standard sudoku rules apply. Digits within a cage cannot repeat and must sum to the total shown in the upper left corner of the cage (standard killer cage constraint). The same digit cannot appear in cells a chess knight's move apart (standard anti-knight constraint).
Wind Up, Wind Down
A straightforward puzzle with a clear solution path, Wind Up Wind Down has garnered many "great puzzle" and "beautiful logic" reactions from the community. It also appears in the Showcase Collection.
Estimated difficulty: 2/5
Rules
Normal sudoku rules apply. Digits in cages must sum to the number shown in the upper left corner of the cage (standard killer cage constraint). Additionally, each position in the 3x3 boxes contains a full set of the digits 1 to 9. In other words, no digit can show up in the same position in two different 3x3 boxes (standard disjoint groups constraint).
Laughing Gas-B
This puzzle is also part of the GAS Collection and is a Website Exclusive.
Estimated difficulty: 1.5/5
Rules
Standard sudoku constraints: each row, column, and box must contain a complete set of the digits 1-9.
Thermometers: Digits on a thermometer must increase from the bulb end to the tip. Digits on the thermometer do not have to be consecutive.