Absolute GAS
The solve path for this is all naked singles, meaning that at every step there is at least one digit that can be placed immediately. This puzzle is so pretty that we didn’t feel we created it but rather discovered it, and that it should be shared. The community seems to agree, having awarded it several "mind-blowing puzzle" and "beautiful logic" reactions. It is currently in the top 10 most solved puzzles of all time on LogicMasters Deutschland.
We are particularly delighted that this puzzle helped inspire the brilliant setter Philip Newman to find new "smallest known givens" for thermo constraint puzzles. (You'll have to join the Discord server to see his post and lovely puzzle.)
Estimated difficulty: 1/5
Rules
Standard sudoku rules apply. Digits on thermometers increase from bulb to tip.
DisArray
This puzzle came out of pondering how SET and disjoint groups might interact. Although it doesn't make use of SET, it's a fun puzzle. It has a unique solution without the kropki dots, but it's a painful slog with a lot of bifurcation to get there. The kropki dots make it a smooth solve and on the easier side, although definitely not a GAS puzzle. DisArray was featured on Cracking the Cryptic on 29 March 2022.
Estimated difficulty: 2/5
Rules
Standard sudoku constraints: each row, column, and box must contain a complete set of the digits 1-9.
Standard arrow constraint: digits along an arrow must sum to the number shown in the attached circle and can repeat if allowed by other constraints.
Standard killer cage constraint: digits within a cage marked by a dashed border cannot repeat and must sum to the total shown in the upper left corner of the cage.
Standard kropki difference dot constraint: digits on either side of a white dot are consecutive. No negative constraint applies.
Standard disjoint groups constraint: Digits in the same relative position within boxes must be different.
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, earning it a place in the showcase.
Estimated difficulty: 2/5 (GAS-level)
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).
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 (GAS-level)
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.
Bastille Day
What better constraint for a Bastille Day puzzle than fortress cells? We sent this in to Cracking the Cryptic on a whim and were delighted to have it featured on 14 July 2022.
Estimated difficulty: 2.5/5
Rules
Standard sudoku constraints: each row, column, and box must contain a complete set of the digits 1-9.
Fortress cells: shaded cells are fortress cells and must be larger than any orthogonally adjacent unshaded cell.
Standard thermometer constraint: digits on a thermometer must increase from bulb to tip.
Cross About Dominoes
We set this puzzle to highlight a particular mathematical property and stunning pattern that emerges from a simple constraint. It was featured on Cracking the Cryptic as A Modular Miracle on 31 August 2022, where it earned us a coveted "take a bow" from Simon Anthony. It also appears in our Indigestion Collection 2.
Estimated difficulty: 3/5
Rules
Normal sudoku rules apply: every row, column, and 3x3 box must include a complete set of the digits 1-9.
Killer cages: digits within cages marked by dashed lines must sum to the number shown in the upper left corner of the cage.
Every diagonal of length 7, 8, or 9 is either modular or unimodular. On modular lines, every set of three sequential digits contains one digit from {147}, one from {258}, and one from {369}. On unimodular lines, all digits are from the same class (all from {147} or all from {258} or all from {369}).
Sawyer Beetle
Our first collaborative set with BremSter, this delightful puzzle was featured on Cracking the Cryptic on 22 October 2022.
Estimated difficulty: 3.5/5
Rules
Normal sudoku rules apply: every row column and 3x3 box must contain a complete set of the digits 1 through 9.
Digits connected by an X sum to 10. Digits connected by a V sum to 5. Not all Xs or Vs are necessarily given.
Digits along a purple renban line form a set of non-repeating consecutive digits in any order.
Any set of three contiguous cells along a beige entropic line must contain one low digit (123), one medium digit (456), and one high digit (789).
Turbulence
The product of a sleepless night, this puzzle also appears in the Indigestion Collection.
Estimated difficulty: 3.5/5
Rules
Standard sudoku rules apply. Digits along an arrow sum to the number in the attached circle and may repeat if permitted by standard sudoku constraints (standard arrow constraint). Digits separated by a white dot form a consecutive pair. Digits separated by a black dot are in a 1:2 ratio (standard kropki dot constraints).
Thermo Dis
Despite its apparent simplicity, this is easily the hardest puzzle we have set to date (as of July 2022). It requires lots of thought about the interplay of the disjoint constraint and the thermos.
Estimated difficulty: 4.5/5 (Indigestion-level)
Rules
Normal sudoku rules apply. Digits on thermometers must increase from bulb to tip but need not be consecutive (standard thermometer 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).