What's tougher about Hard?
Hard puzzles start with very few sudoku digits and only one pre-revealed ship segment. You'll need to squeeze every clue from the row/column counts and the sudoku logic working together.
The good news: every Hard puzzle has exactly one solution and can be solved without guessing. If you feel stuck, the Check and Hint buttons are there to help.
Advanced deduction steps
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Zero and full rows/columns first
Count = 0 means no ships. Count = row/col length means all cells are ships. Resolve these before anything else.
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Partial elimination
If a row count is 2 and you've ruled out 7 cells as ship-free, the remaining 2 cells must both be ships.
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Use confirmed ships to cascade
Each confirmed ship removes cells from its row/col count. Update counts as you confirm ships.
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Cross-check with sudoku
A confirmed ship means those cells' digits are locked. That can solve neighbouring cells in the same row, column or box.
常見問題
Is Hard too tough for kids?
Hard is aimed at kids who've already played lots of Easy and Medium. If it feels overwhelming, go back to Medium for a few sessions first.
Can I solve Hard without guessing?
Yes — every puzzle has exactly one logical solution. If you're stuck, tap Hint to unlock one cell and keep going.
試試其他數獨遊戲
規則不同，盤面一樣親切。下一局選一個相關的謎題吧。