Sudoku Help

Need a hand with Sudoku? You’re in the right place! Here you’ll find step-by-step guides, quick tips, and advanced strategies (coming soon) to help you become a puzzle pro.

How to Play is the quick-start. Rules is the reference. Walkthrough is a visual tour. FAQ is for quick questions. Advanced Strategies is where the “teach me your ways” stuff will live soon.

FFG difficulty levels: Easy, Medium, Hard, Expert, and Legendary.

Quick Start Instructions

  • Fill every row, column, and 3×3 box with numbers 1–9 (no repeats).
  • Given numbers are fixed and never change.
  • Start with areas that are almost complete to find the next sure number.
  • Pencil Mode lets you jot candidates before committing.

Core Techniques

  • Naked Single: one candidate fits a cell.
  • Hidden Single: one spot fits a number inside a row, column, or box.
  • Locked Candidate: a box-line interaction removes candidates elsewhere.
  • Naked Pair: two matching candidate cells eliminate peers.
  • Hidden Pair / Naked Triple: tighter candidate groups that prune a unit.
  • X-Wing: a row/column fish pattern that removes a repeated candidate.
  • Guess / Backtracking: mostly appears in Expert and Legendary.