Logic Masters Deutschland e.V.

This is the full version of the "X-Monotonic Arrows" ruleset. Check out the 6x6 version here: X-Monotonic Arrows (mini)

Click the image or this link to play online.

Rules:

• Normal Sudoku Rules Apply: Fill every row, column, and 3x3 box with the digits 1-9 without repetition.
• X-Monotonic Arrows: The digit X in the first cell seen by a gray arrow outside the grid determines a sequence of X cells in the arrow's direction (including the first cell). This sequence must be strictly monotonic (either strictly increasing or strictly decreasing).
• Negative Constraint: All possible X-Monotonic Arrows for X > 2 are given. If a border cell contains a digit X (where X > 2) and is the start of a strictly monotonic sequence of at least X cells, an arrow in the direction of the sequence must be present.

Have fun!