Logic Masters Deutschland e.V.

Chaos Construction: Divide the grid into regions of nine orthogonal cells, and place each digit 1-9 in every row, column, and region. Circled digits (unshaded) indicate the number of unshaded cells in the regions that they inhabit. No region is fully unshaded.

Japanese Sum: Clues outside the grid give the sums (in order) of contiguous runs of unshaded cells in their row/column. A “?” denotes a single-digit sum, a “??” denotes a double-digit sum, and a “*” can indicate any number of runs, including none. R9C5 is shaded.

Country Road: Draw a non-intersecting loop that passes through each region exactly once, moving orthogonally (and exclusively) through every unshaded cell. Orthogonal cells in different regions cannot both be shaded. In such dominoes, opposite-shaded digits must not be consecutive and same-shaded digits must not have a 2:1 ratio.

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Example grid and solution for a 6x6 puzzle in which all the regions are standard. To avoid confusion over the final rule, I've placed yellow dots between cells that can't be consecutive and purple dots between cells that can't be in a 2:1 ratio.

Penpa

CTC

NOTE: The Penpa link checks for sudoku AND shaded cells while CTC only checks Sudoku. Just something to keep in mind if you're having technical issues :) Happy solving!