Sudoku variants

Variants keep the classic Sudoku grid and add one new rule. Each has its own puzzles here, at two levels, with hints that explain the variant rule too. Every puzzle has exactly one solution.

• Killer SudokuCages and sums
• Sudoku XDiagonals count too
• Thermo SudokuRising thermometers
• Anti-KnightNo knight’s moves
• Anti-KingNo touching, even diagonally

Which one to try first

New to variants? Sudoku X is the gentlest step: one extra rule, and it still feels like classic Sudoku. Thermo is a pure logic favourite. Killer is the most popular, with sums to work out.

Play a variant