Logic Masters Deutschland e.V.

Normal sudoku rules apply. The digits 1-9 must appear once in each row, column, and 3x3 box.

Loops: Draw four loops in the grid. Each large colored circle is part of a different loop. Loops move through the center of cells and do not branch. They do not intersect themselves nor other loops. Orthogonally- and diagonally- touching cells may contain parts of the same loop. All cells in the puzzle are part of a loop.

Color Quads: each large white circle contains 1-4 smaller colored circles. The four cells surrounding the quad clues must contain at least one loop cell of each color represented in the quad clue. Colors not in the quad clue do not have their loop in cells surrounding the quad. Loops cannot pass through white quad circles.

Kropki: Cells separated by smaller white dots contain consecutive digits. A loop must pass through small white dots.

XV: Cells separated by an X sum to ten. Cells separated by a V sum to five. Loops cannot pass through Xs and Vs

Segments: Small white squares must have a loop pass through them. They divide their loop into line segments with the following constraints:

*Purple loop– Renban – digits along the loop segments form a set of consecutive, non-repeating digits in any order.
*Green loop – German whisper – adjacent digits along the loop segments must differ by at least five.
*Orange loop – Dutch whisper – adjacent digits along the loop segments must differ by at least four.
*Blue loop – Modulo three – Every set of three adjacent digits along loop segments must have one digit from the set (1,4,7), one from the set (2,5,8), and one form the set (3,6,9).