Weekly Competition
No active competition right now. Check the schedule below or play today's Daily Challenge to stay sharp.
Competition Rules
- All competitors receive the same puzzle at the same time.
- You must have an email-verified account to enter - register here.
- Rankings are based on: valid completion → highest score → fastest time → fewest hints → fewest mistakes → earliest submission.
- Suspicious completion times are automatically flagged for review.
- Competition window is typically one week.
- Using the Sudoku Solver during the competition is against the rules.
How scoring works
| Factor | Effect on score |
|---|---|
| Completion | Required - No score for incomplete puzzles |
| Speed | Faster times = higher score multiplier |
| Mistakes | Each mistake reduces score (max 3 mistakes allowed) |
| Hints used | Each hint reduces score |
| Notes mode | No penalty - Use pencil marks freely |
Prepare for competition
Competition puzzles are typically at Hard to Expert difficulty. To maximise your score:
- Master Hidden Singles - The technique most commonly needed at Hard level
- Learn Obvious Pairs to eliminate candidates quickly
- Practice with the Daily Challenge to build speed under pressure
- Read the full How to Play guide for strategy tips