Logic Masters Deutschland e.V.

Rules:

-The digits 1-9 appear once each within the center digits of the boxes.

-In boxes with a composite number (1,4,6,8,9) in the center (Hereafter CN boxes), normal sudoku rules apply.

-In boxes with a prime number (2,3,5,7) in the center (Hereafter PN boxes), normal sudoku rules do not apply, but must not prevent CN boxes from working properly.

-White dots in a CN box signify a difference of 1. In a PN box, they signify a difference of either 2,3,5, or 7.

-Black dots always signify a ratio of 2:1 between digits.

-Gray dots are where both a black and white dot apply.

-All dots within boxes are given, none of the dots between boxes are given.

-Digits that lie on an arrow sum to the digit in the circle.

-All prime digits are orthogonally connected.

-PN boxes have a prime number of prime digits not equal to the center value (ie the center digit is 2 therefore there are 3,5, or 7 prime digits in the box).

-The sum of digits contained within a PN box is a prime.

-The number of boxes containing all the prime digits is prime.

Play on Penpa: https://tinyurl.com/yufghn4z

Play on SudokuPad: https://tinypuz.com/yl2fyr8h

Example grid: