Logic Masters Deutschland e.V.

Normal sudoku rules apply.
Modified Nurikabe: Draw 8 lines of length 2 or more such that each circle is the center of one of these lines. The lines only move orthogonally and may not touch themselves or each other orthogonally. Each 2x2 must contain at least one cell on a line. Non-line cells form a single orthogonally connected area.
Zipper Islands: Digits an equal distance to the (circled) center of a line sum to its central digit.
Partial Suguru: Digits never repeat on lines. Circles marked with "S" also count the number of cells on their line.
Ambiguous Cave: A digit in a diamond is of either "type" (line or non-line) and counts how many cells of its own type it sees in the row and column combined, including itself. The other type blocks vision.

Rules