Normal sudoku rules apply. If two digits are separated by a black dot then one digit is double the other. Digits separated by a white dot are consecutive. Not all dots are given. Deducing the digit in the highest visible checkpoint (marked with a green square and a number) will reveal new cells and potentially a new checkpoint. Each line follows the rules of one specific constraint type from the following list. It is up to the solver to determine which line belongs to which type. Each line constraint type may contain NO REPEATED DIGITS anywhere in the puzzle. At the start of the puzzle, all lines are Region Sum Lines (ie the 3x3 box borders divide the lines into segments; each segment along an individual line has the same sum). When a new checkpoint is revealed, remove the determined line types and all entered digits EXCEPT those on checkpoints. You are now allowed a new line constraint! Checkpoint 1: Additionally, the lines can now be German Whisper lines (Adjacent digits differ by at least 5) Checkpoint 2: Additionally, the lines can now be Parity lines (Digits alternate between odd and even digits) You have completed the puzzle when all 3 checkpoints are revealed and the complete grid is filled.