Logic Masters Deutschland e.V.

Standard sudoku rules apply: each row, column, and 3x3 box must contain all the digits from 1 to 9.

XV pairs: digits in cells separated by a V sum to 5; digits in cells separated by an X sum to 10.  Not all Xs or Vs are necessarily given.

Sandwich variant: clues outside the grid are sandwich clues.  In a row or column pointed to by a clue, the clue is the sum of the digits between the 1 and the 9. In a diagonal pointed to by a clue, the clue is the sum of all digits between the first 1 and first 9 in the diagonal (as seen from the clue).  Note that it is possible for a 1 or 9 to be part of the sum, as long as it is not the first 1 or first 9 seen from the clue.

Play in SudokuPad