Logic Masters Deutschland e.V.

Rules:

Place the digits 1-6 once each in every row and column.

Arrows: Digits on an arrow sum to the digit in the attached circle. Digits may repeat on an arrow if allowed by other rules.

Kropki: Digits separated by a white dot are consecutive. Not all dots are shown.

Knight's tour: A knight moves on the grid using knight's move (in chess) such that every cell is visited exactly once. The tour is closed (i.e. the cell the knight visits last is one move away from the starting cell). Whenever the knight moves to a new cell, the digit in the cell increases by 1, with 6 followed by 1 (e.g. if the knight moves from r2c4 to r3c6 and r2c4 contains a 4, then r3c6 contains a 5).

Link to Sudokupad