Thermal Doppelgangers
(Published on 23. July 2025, 07:44 by bodemeister)
Rules:
- CHAOS CONSTRUCTION:
- Divide the main grid into 9 regions, each made of 9 orthogonally connected cells.
- The left-most cell in the top row of a region is called the region indicator, and the right-most cell in the bottom row of a region is called the region closer.
- The region indicators, read from left to right starting with the top row and working downwards, form a strictly increasing sequence. - THERMOS: In the finished grid, each region contains a (not necessarily unique) thermo whose bulb is the region indicator and whose tip is the region closer. Digits increase along each thermo from the bulb to the tip. Each thermo may move orthogonally and/or diagonally but is confined to a single region.
- DOPPELGANGER:
– Every row, column, and region must contain the digit 0 always, as well as eight out of the nine digits from 1 to 9 (ie, it will be missing one digit that is not 0).
– No two rows, no two columns, and no two regions may be missing the same digit.
– For each 0 in the grid, the digits missing in its row, its column, and its region must be three different digits. - ARROWS: A cell with one or more arrows containing digit N indicates that for each arrow, there is a region indicator or region closer N cells away in the direction of the arrow. A cell with a question mark contains one or more invisible arrows.
- TRACKING CELLS: Cells outside the main grid may be used for doppelganger tracking.
Solution code: Row 1 followed by Column 5 of the main grid. Include an x for region borders not counting the edge of the grid.
Comments
on 25. July 2025, 13:33 by Andrewsarchus
Amazing how everything resolves so beautifully with such a minimal set of clues. Great puzzle and fun to solve!
on 24. July 2025, 23:59 by sanabas
Loved it
on 24. July 2025, 01:42 by earthpuzzles
Fantastic combo of complex ruleset and minimalistic grid — once I understood how everything interacted, the solve path felt like the perfect mix of tough enough to be satisfying and smooth enough to never strand me
on 23. July 2025, 18:11 by wullemuus
This is the ultimate increase run in CC, invisible thermos and Doppelgänger puzzles! Such a smooth solving (esp. the region building) with minimalistic clues. So impressive!
