Logic Masters Deutschland e.V.

Co-created by (in order of contribution): Jeet Sampat, Myxo, dumediat, damasosos92, Agent, SSG, glum_hippo, Playmaker6174, tallcat, Malrog, mnasti2, Piatato, Christounet, MaizeGator, sfushidahardy.

A couple of months ago, I sent an empty grid to Myxo with a weird "almost Sudoku" rule-set, and asked him to add at most one line of rule and at most one clue to the grid. Myxo would then send it to someone else with the same requirement and so on until the grid achieves a unique solution. This is the outcome of this project and I am quite pleased with the results. I hope you enjoy it as much as we enjoyed making it!

The difficulty is between 3* and 4*, with the toughest part being scanning the grid.

Rules:

Almost Sudoku: Fill the grid with digits 1-9 so that each row, column, and box contains exactly 8 unique digits.

Arrows: Digits along an arrow must sum to the digit in the attached bulb.

Slow Thermometers: Digits along a thermometer must not decrease from the bulb end to the tip.

German Whispers Line: Two cells connected by a green line must have a difference of at least 5.

Skyscraper Clues: Clues outside the grid give the number of digits visible from the clue's position, given that each digit blocks the view of any digits behind it that aren't larger than it.

Region Sum Lines: Along a blue line, box borders divide the line into smaller segments with the same sum. Digits can repeat along a segment if allowed by other rules.

Try it on Sudokupad.

Puzzle: