Logic Masters Deutschland e.V.

Knowing about the Doppelgänger ruleset by Kafkapharnaum, the concept of Doppelgänger Doppel-Dög was just irresistible... so here it is.

• Doppelgänger Sudoku:
  • Every row, column, and box contains the digit 0 and eight out of the nine digits from 1 to 9 (i.e. it's missing one digit that is not 0)
  • No two row, no two column, and no two box may be missing the same digit.
  • For each 0 in the grid, the digits missing in its row, its column, and its box must be three different digits.
• Doppel-Dög loop:
  • Draw an orthogonal non-branching closed loop that doesn't cross or touch itself, not even diagonally.
  • The loop "starts" at the cell marked with the dog and is considered to be oriented in the direction indicated by the arrow (i.e. r7c6 and r7c7 are in the loop).
  • A cell on the loop with a digit D will have a value equal to the cell D steps away along the loop in the orientation given by the arrow.
  • Cells not on the loop will have a value equal to the digit in them.
• Adjacent digits (not values) along the loop must have a difference of at least 5.
• Values in a cage sum to the indicated total. Digits and/or values may repeat inside a cage.
• Cells marked with a circle are not part of the loop and have a digit that equal to the count of the, up to 8, neighboring loop cells.
• Clues outside the grid show the value sum of loop cells in the indicated row/column.

Online in Sudokupad (and with note-taking spaces)

Another Doppel-Dögs:

• can i pet that dog!?
• please, can we keep him!?
• Convection Currents by ThePedallingPianist
• Doppel-Dög Sandwich by phil_the (hat)
• Tentropic Terrier by Scojo
• a changed man