Hard Greater Than Sudoku
A serious challenge awaits. Hard Greater Than Sudoku puzzles require deep mastery of the variant's constraints alongside advanced Sudoku logic like hidden pairs, X-Wings, and multi-step deduction chains.
What to expect at Hard level
Hard Greater Than Sudoku puzzles have fewer starting clues and require multi-step reasoning. The variant constraint creates subtle eliminations that are easy to miss. Expect to use pencil marks extensively and revisit cells as new information emerges.
Ideal for experienced Sudoku players who want a genuine mental challenge with a unique twist.
Difficulty overview
About Greater Than / Less Than Sudoku
Greater Than Sudoku (also called Futoshiki-style Sudoku) places < and > inequality signs between adjacent cells. The sign indicates which of the two cells must hold the larger value. Some variants replace all given digits with inequality signs; others provide a hybrid. The constraints create chains of reasoning: if A > B > C > D, then A ≥ 4, B ≥ 3, C ≥ 2, D ≥ 1.
Solving Techniques for Hard Level
| Technique | Description | Level |
|---|---|---|
| Chain Inequality — Minimums | Link inequalities in a chain: if A > B > C, then A ≥ 3, B ≥ 2, C ≥ 1. Use these minimums to prune candidates immediately. | Beginner |
| Chain Inequality — Maximums | In the chain A > B > C > D, also bound from above: A ≤ 9, B ≤ 8, C ≤ 7, D ≤ 6. | Beginner |
| Inequality Propagation | After placing a digit, check all inequality arrows from that cell and eliminate impossible values from its neighbours. | Intermediate |
| Forced Single via Range | When an inequality chain reduces a cell's valid range to a single digit, place it directly. | Intermediate |