Delta Rune

27 September 2026

Rules:

• Classic Sudoku:

  Every row, column and 3x3 box must contain every number from 1 to 9.

• Arrows:

  Numbers along an arrow sum up to the total in the circled cell.

• Palindrome Lines:

  Digits along a grey line read the same backwards and forwards.

• Region Sum Lines:

  Box borders divide a blue line into multiple segments which have the same sum.

• Renban:

  All digits along a purple line must form a consecutive sequence (in no specific order).

• German Whispers:

  Every two consecutive digits along a green line must have a difference of at least 5.

• Counting Circles:

  Any digit in a circle indicates exactly how many circles contain that digit (arrow circles are NOT included).

• Kropki:

  Two digits separated by a white dot are consecutive; two digits separated by a black dot have a 1:2 ratio.

Play it online in SudokuPad.

This puzzle is also on Logic Masters Germany.