🔢 Sudoku Game Guide

This guide explains Sudoku in simple words. We keep it friendly and practical so you can solve cleanly without stress. No fancy talk — just clear steps and tips.

🎯 Game Objective

Fill the 9×9 grid with numbers 1–9. Each row, each column, and each 3×3 box must have 1–9 without repeats. Some numbers are given at the start — you place the rest using logic only.

📋 Basic Rules

🔢 Numbers 1–9

Use digits 1 to 9 only. No repeats in any row, column, or box.

📏 Rows

Each row contains 1–9 once. If a number is already there, it can’t appear again.

📐 Columns

Each column has 1–9 once. Same logic as rows.

📦 3×3 Boxes

Each small 3×3 box also needs 1–9 once. Check all three: row, column, box.

🧠 Basic Solving Techniques

1️⃣ Naked singles

A cell that can only be one number. If all others are blocked by row/column/box, place the last one.

2️⃣ Hidden singles

A number that fits only one spot in a row/column/box. Check each missing digit and see where it can go.

3️⃣ Pencil marks

Note small candidate numbers to keep track. Update them as you place numbers.

🎓 Intermediate Techniques

🎯 Pointing pairs/triples

If a candidate in a box sits only in one row or column, remove that candidate from that row/column outside the box.

📦 Box/line reduction

If a number in a row/column must be in one box, clear that candidate from other cells in the box.

👥 Naked pairs

Two cells share two candidates? Remove those candidates from the rest of the unit.

🕵️ Hidden pairs

Two digits can only go in two spots? Keep those, clear other candidates in those cells.

🚀 Advanced Strategies

⚔️ X-Wing

Same candidate forms a neat rectangle across two rows and two columns. Use it to remove that candidate elsewhere.

🐟 Swordfish

Like X‑Wing but with three rows/columns. Harder pattern, same elimination idea.

🔗 Simple coloring

Mark linked candidates with two colors. Contradictions reveal removals quickly.

🌐 Forcing chains

Follow “if this then that” chains. Use contradictions to force placements.

📝 Step‑by‑step solving

  1. Find singles: Place any cell that only has one possible number.
  2. Hidden spots: If a digit fits only one cell in a unit, place it.
  3. Add notes: Use pencil marks for candidates.
  4. Eliminate: Remove candidates using pairs/pointing rules.
  5. Refresh notes: Keep candidates clean as you place numbers.
  6. Repeat: Loop these steps slowly until the grid fills.
  7. Advanced if needed: Use X‑Wing/Swordfish on hard puzzles.

💡 Tips that help

  • Start where it’s full: Busy rows/columns/boxes give quick placements.
  • Slow is fine: Clean logic beats speed and guesswork.
  • Keep notes tidy: Update pencil marks often.
  • Don’t guess: If stuck, switch area and return later.
  • Verify moves: Check row, column, and box before placing.
  • Short breaks: Look away for 10–20 seconds when stuck.

🚫 Common mistakes

❌ Guessing

Try not to guess. Use logic and change focus if stuck.

❌ Ignoring constraints

Always check row, column, and box. One miss creates errors fast.

❌ Messy notes

Untidy candidates cause confusion. Keep them clean and current.

❌ Rushing

Going too fast leads to mistakes. Steady wins here.

📊 Difficulty

🟢 Easy

Focus on singles and simple notes. Calm pace.

🟡 Medium

Add pairs and pointing rules. Good challenge.

🟠 Hard

Use more elimination and sometimes advanced patterns.

🏃‍♂️ Speed Solving Tips

👁️ Pattern Recognition

Train your eyes to quickly spot common patterns and number placements.

🔄 Technique Order

Develop a consistent order for applying techniques to avoid missing opportunities.

⚡ Quick Scanning

Practice rapid visual scanning to identify naked and hidden singles faster.

🧠 Mental Notes

For easier puzzles, try to solve without pencil marks to improve mental calculation.

🎯 Practice Recommendations

🌱 Beginner (Week 1-2)

  • Solve 2-3 easy puzzles daily
  • Focus on naked and hidden singles
  • Practice using pencil marks
  • Learn to scan systematically

🌿 Intermediate (Week 3-6)

  • Solve 1-2 medium puzzles daily
  • Learn pointing pairs and box/line reduction
  • Practice naked and hidden pairs
  • Work on speed and accuracy

🌳 Advanced (Month 2+)

  • Tackle hard and expert puzzles
  • Master X-Wing and Swordfish
  • Learn coloring techniques
  • Challenge yourself with time limits

🎮 Ready to solve?

Start a new game, pick Easy/Medium/Hard, and work slowly with singles, notes, and clean eliminations.

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