🎯 Sudoku Challenge

📐 The Three Golden Rules

Fill the grid so that every row, every column, and every 3×3 box contains the digits 1 through 9 exactly once.

Rule 1: Each Row

Every row must contain numbers 1-9 with no repeats.

✅ Valid row — each number appears once

Rule 2: Each Column

Every column must contain numbers 1-9 with no repeats.

Rule 3: Each 3×3 Box

Each of the nine 3×3 sub-grids must contain numbers 1-9 with no repeats.

✅ One 3×3 box — must contain 1-9

🚫 Common Mistakes

• Duplicate in a row: Two identical numbers in the same row
• Duplicate in a column: Two identical numbers in the same column
• Duplicate in a box: Two identical numbers in the same 3×3 box
• Guessing: Placing a number without verifying it doesn't conflict elsewhere

💡 Beginner Strategy: Cross-Hatching

1. Pick a number (e.g., 1).
2. Look at each 3×3 box. Where can 1 go?
3. Eliminate rows and columns that already contain a 1.
4. The remaining empty cell in that box must be where 1 goes.
5. Repeat for numbers 1-9 across all boxes.

🧠 Intermediate Strategy: Pencil Marks

Mentally note which numbers could go in each empty cell. When a cell has only one possible number left, that's your answer.

Example: If a row already has 1,3,5,7,9 and the column has 2,4,6 — the only possible number for that intersection is 8.

🔥 Advanced Strategy: Hidden Singles

Within a row, column, or box, if a number can only go in one possible cell (even if other numbers could also go there), that cell must contain that number.

📊 Difficulty Levels

• Easy — 35 empty cells. Good starting point for beginners.
• Medium — 45 empty cells. Requires cross-hatching and pencil marks.
• Hard — 55 empty cells. Requires advanced techniques. For experienced players.

🏁 How Competitions Work

Competitions are created by Administrators. They select specific puzzles from the puzzle library, set a date range, and launch the competition.

For Players

1. Go to the 🏁 Competitions tab
2. View Active Competitions — these are live right now
3. Each competition shows the number of puzzles included
4. Click 📊 View Leaderboard to see current rankings
5. Solve the puzzles in the Play tab — your completions automatically count toward active competitions

Competition Scoring

• Ranked by number of puzzles solved within the competition
• Tiebreaker: average solve time (faster = higher rank)
• Only puzzles listed in the competition count
• You can solve competition puzzles at any difficulty level

🏆 How the Leaderboard Works

The leaderboard ranks all players by:

1. Total puzzles solved (most important)
2. Average solve time (tiebreaker — lower is better)

Rank Badges

• 🥇 Gold (Rank 1): Top player — most puzzles solved
• 🥈 Silver (Rank 2): Second place
• 🥉 Bronze (Rank 3): Third place

Your Stats Bar

The stats bar at the top of the page shows:

• Solved: Total number of unique puzzles you've completed
• Avg Time: Your average solve time across all puzzles
• Best: Your fastest single solve time

Tokenkey Filtering

If a ?id=TOKENKEY is in the URL, the leaderboard only shows players within that tokenkey's ecosystem. This lets you run private leaderboards for specific groups or funnels.

🎮 Player All Users

What Players Can Do

• Play Sudoku at any difficulty level
• Track personal stats (solved count, average time, best time)
• Compete on the global leaderboard
• View and participate in active competitions
• See competition leaderboards in real-time
• Navigate with keyboard or touch controls

Player FAQ

Q: Can I solve the same puzzle twice?
A: No — the system prevents duplicate completions. Each puzzle can only be solved once per user. This keeps the leaderboard fair.

Q: Does the Check button affect my score?
A: No — checking your progress is free and doesn't affect your time or ranking.

Q: How do competitions work if puzzles are random?
A: Competitions use specific puzzle IDs from the library. All players in a competition solve the exact same puzzles — it's completely fair.

👑 Administrator Role 9

What Admins Can Do

• Everything players can do
• View full analytics — who solved what, when, and how fast
• Browse the Puzzle Library — every puzzle ever generated with stats
• Create competitions — select specific puzzle IDs, set dates, and launch
• Filter analytics and puzzles by tokenkey
• All admin data is scoped by ?id=TOKENKEY when provided

Creating a Competition

1. Go to the 👑 Admin tab
2. Click 📋 Load Puzzle Library to see all available puzzles
3. Note the Puzzle IDs you want to include
4. Fill in the competition form:
   • Name: e.g., "Weekend Challenge"
   • Description: Any rules or notes for players
   • Difficulty: Filter puzzles by difficulty or include all
   • Puzzle IDs: Comma-separated list (e.g., 12,15,19)
   • Start/End dates: When the competition runs
5. Click 🚀 Launch Competition
6. Players will see it in the 🏁 Competitions tab immediately

🔐 Tokenkey Scoping

All puzzles, completions, and competitions are scoped by tokenkey when ?id=TOKENKEY is present in the URL.

• With tokenkey: Puzzles and leaderboards are filtered to that tokenkey's ecosystem
• Without tokenkey: All data is global across the platform
• This allows private competitions for specific funnels or groups