Sudoku Classic

Sudoku 4x4 – Extreme

The Extreme level Sudoku 4x4 puzzle is the most challenging variant in this category. It’s designed for elite players who have mastered every technique and thrive on solving puzzles with virtually no given clues. Every number must be placed through deep logic, multiple layers of deduction, and flawless reasoning. One false step can undo the entire solution.

Puzzle Characteristics

• Difficulty: Extreme
• Grid Size: 4x4
• Regions: Four 2x2 subgrids
• Clues Provided: Minimum (as few as 1 or 2 numbers)
• Complexity: Very high – intended only for the most experienced solvers

Puzzle Clues

• Row 1: blank, blank, blank, blank
• Row 2: blank, blank, blank, blank
• Row 3: blank, 2, blank, blank
• Row 4: blank, blank, blank, blank

Objective

Fill in the grid so that each row, column, and 2x2 region contains the numbers 1 to 4 exactly once. With almost no initial guidance, players must rely on strategic deduction and advanced logic to progress.

Recommended Techniques

• Full Candidate Tracking: Record all possible values for each cell and update them as you progress.
• Chain Deductions: Use advanced logical chains to infer correct placements indirectly.
• Subset Elimination: Detect hidden pairs, triples, or locked candidates to eliminate options.
• Backtracking Validation (Optional for Review): Verify complex paths logically before committing.
• Extreme Focus: Be meticulous—this level punishes even the smallest oversight.