Logic Masters Deutschland e.V.

Click here to play on SudokuPad.

Chaos Construction: Divide the grid into orthogonally connected, non-overlapping regions. Fill every row, column, and region with the digits 1-5 once each.

Region-counting circles: A digit in a circle counts how many distinct regions are represented in its orthogonal neighbors. For instance, if a circle contains a 2, its orthogonal neighbors cannot all be from the same region; they must be from exactly two distinct regions.

Kropki: Digits separated by a (smaller) white dot are consecutive. Not all dots are given.

I strongly suspect there is an official name (or at least a better name) for the "region-counting circles" rule, but I don't know it; feel free to comment it if you do and I'll edit!