Normal sudoku rules apply. Digits are grouped into entropic sets: Low → {1, 2, 3}; Mid → {4, 5, 6}; High→ {7, 8, 9}. A digit placed in a circle indicates the size of the orthogonally connected group of cells that all contain digits from the same entropic set as that digit. No region contains more than one circled cell. Not all regions contain a circle. Digits separated by a white dot must be consecutive. If two digits are separated by a black dot then one digit is double the other.