Rules

• Fill every cell with a number from 1 to 6.
• Each row must contain all digits 1–6 with no repetition.
• Each column must contain all digits 1–6 with no repetition.
• Each region (or block) must contain all digits 1–6 with no repetition.
• Use logic only, no guessing required for well-formed puzzles.

Strategies & Tips

• Scan rows & columns: Look for missing numbers that have only one possible position.
• Region elimination: Use region constraints to eliminate candidates from rows/columns.
• Single candidates: If a cell can only be one number, place it and propagate the constraint.
• Pairs & triples: When two cells in a house (row/col/region) share the same two candidates, remove those candidates from other cells in that house.
• Work systematically: Alternate scanning rows, columns, and regions so you don’t miss a forced placement.

Common Mistakes