Logic Masters Deutschland e.V.

This puzzle began as a conversation between me and ChinStrap nearly a year ago. The groundwork was laid last March, but the puzzle collected dust for most of 2025. I picked it up again last, week, and hope you enjoy the result. Any and all feedback is appreciated! Big thanks to ChinStrap for the inspiration and test!

If you enjoy yourself, and want to try more shenanigans with appendix lines, I have another puzzle or two you can try.

Rules:

Sudoku: Place the digits 1-9 once each in every row, column and box.

Appendix Line: Teal lines are like an index line, but with repeating positions. If a digit D appears in a Pth position along the line, starting at the large diamond, then the digit P must appear in a Dth position along the line.

Position counting repeats after the 9th space. Small arrows are placed between the 9th and 10th positions along the line, with arrows pointing at the new position 1.

For example, if a line is 14 cells long, and it contains a 3 in the 7th position, then a 7 must appear in either the 3rd or the 12th position.

Equal Sum Line: Teal lines are also Equal Sum Lines. Circles along the line divide it into segments. The digits in each segment sum to the same value.

Tentropy Lines: Along a hollow orange line, any string of 4 adjacent digits must contain a digit from each of the four tentropy classes: {1, 9}, {2, 8}, {3, 7}, and {4, 6}.

Quads: A digit that appears in a white circle must be placed in one of the four cells touching that circle.

Hope you enjoy, and click the puzzle to play!