Logic Masters Deutschland e.V.

• Normal sudoku rules apply: Place the digits 1-9 once each into every row, column, and 3x3 box of the inner sudoku grid.
• Digits may appear in cells outside of the sudoku grid (outside cells), and up to two digits may appear in a single outside cell. If an outside cell contains two digits, its value is a two digit number which is a concatenation of the two digits it contains in some order, though 0 can never be the leading digit. For example, an outside cell containing 1 and 3 could have the values of 13 or 31, but an outside cell containing 0 and 2 could only have the value of 20.
• Quads: Digits in a circle must appear somewhere within the 4 cells surrounding the circle, at least as many times as they appear in the circle.
• X-Sums: Values of outside cells give the sum of the first X cells inside of the sudoku grid in the direction of the outside cell, where X is the digit in the first cell in that direction.

Solve in SudokuPad