Explore advanced Sudoku variations. Each variant introduces unique geometric or mathematical constraints.
Both main diagonal lines must also contain digits 1 to 9 exactly once.
Four extra 3×3 shaded windows that must also contain digits 1 to 9.
Cells a knight's move apart cannot contain the same digit constraint.
Cells a king's move apart (diagonals included) cannot share a digit.
Digits along a thermometer must strictly increase from bulb to tip.
Digits on an arrow line must sum to the digit inside its attached circle.
Digits along marked lines read identically both forwards and backwards.
Digits on Renban lines form a consecutive non-repeating sequence.
White dot = consecutive digits. Black dot = one digit is double the other.
V clue = adjacent cells sum to 5. X clue = adjacent cells sum to 10.
Inequality signs between adjacent cells define relative digit sizes.