Taking the scenic route
- Quadruples
The brief
- Normal sudoku rules apply, i.e. each row, column and 3x3 region has to contain the digits from 1 to 9 once each.
- Quadruple: Digits in a circle must appear in one of the four surrounding cells.
- Omnipotent Loop: Draw a one-cell wide loop into the puzzle. The loop may only move orthogonally from cell to cell, does not branch or cross itself and must not touch itself neither orthogonally nor diagonally. The loop forms a so-called Omnipotent Line, i.e. each pair of adjacent digits on the loop must fulfill either an X, V, white or black Kropki dot clue. In other words, any pair of adjacent digits on the loop must sum to 5 or 10, be consecutive or in a 1:2 ratio. (At least one of these constraints must be met, it is allowed that two constraints are fulfilled simultaneously.) For example, a 3 may be adjacent on the loop to either a 2 (V or white Kropki dot), a 4 (white Kropki dot), a 6 (black Kropki dot) or a 7 (X).
- Non-loop sums: Clues outside the grid indicate the sum of all non-loop digits in the respective row or column up to the first loop cell. (The digit in the loop cell is not included in the sum.) In other words: A clue indicates the sum of all seen non-loop cells where a loop cell blocks vision.