Logic Masters Deutschland e.V.

This puzzle was made for round 1 of Agent's Puzzle Agency Championship. The prompt for this round was to create a puzzle using Knapp Daneben in a relevant way.

Solve here:
SudokuPad
Penpa

- Sudoku: Place the digits 1-9 once each in every row, column, and 3x3 box.

- BYO Hashiwokakero (off-by-one): The given digit marks one island. Place 9 more islands in the grid, one in each 3x3 box. These 9 additional islands must contain a complete set of the digits 1-9.
Draw a series of bridges connecting these islands such that the following 6 criteria are followed:
1) Bridges must begin and end at distinct islands, traveling in a straight line through the center of cells.
2) Bridges must not cross any other bridges or islands.
3) Bridges may only run orthogonally, not diagonally, and may not turn.
4) At most two bridges connect a pair of islands.
5) Bridges must connect the islands into a single connected group.
6) The number of bridges connected to each island must be one more, or one less than the digit on that island.

- Hashiwokakero Bridges (off-by-one): For every bridge, the value of each cell along the bridge must be one more, or one less than the digit in that cell. Note, for island cells, this value may be different for each connected bridge, or different from the island clue value.
1) If two islands are connected by a single bridge, the values along the bridge must strictly increase from one island to the other.
2) If two islands are connected by a double bridge, adjacent values along the bridge must differ by at least 5.

- XV (off-by-one): Every X or V clue is off by exactly one.
a) Cells joined by an X must contain digits that sum to either 9 or 11 (not 10).
b) Cells joined by a V must contain digits that sum to either 4 or 6 (not 5).

- Quadruples (STANDARD): The digit in a circle must appear in one of the surrounding four cells.