Sudoku

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How to Play Sudoku

Sudoku is one of the world's most popular logic puzzles, enjoyed by hundreds of millions of players across every age group. The game is played on a 9×9 grid divided into nine 3×3 boxes. Some cells are pre-filled with digits — these are your starting clues. Your goal is to fill every empty cell with a digit from 1 to 9, following three simple rules that must all hold true simultaneously at all times.

The Three Rules

  • Every row must contain each of the digits 1 through 9 exactly once — no repeats, no omissions.
  • Every column must contain each of the digits 1 through 9 exactly once.
  • Every 3×3 box (there are nine of them, outlined with a thicker border) must contain each of the digits 1 through 9 exactly once.

These three constraints together mean that every cell has exactly one correct digit that satisfies all rules simultaneously. A properly constructed Sudoku puzzle has a unique solution — there is never more than one correct answer. On MIA Games, all puzzles are algorithmically verified to have exactly one solution before they are presented to you.

Getting Started — A Beginner's Method

If you are new to Sudoku, the best way to start is by scanning for naked singles — cells where only one digit can legally go. Look at a row: if eight of the nine digits are already placed, the ninth cell must hold the missing digit. Repeat this logic for columns and boxes. Once you have filled all the obvious naked singles, move to hidden singles: a digit that can only go in one cell within a row, column, or box, even if that cell appears to have multiple candidates.

Difficulty Levels

MIA Games Sudoku offers three difficulty settings, each controlling the number of pre-filled clues and the complexity of logic required to solve the puzzle:

  • 😊 Easy (36 clues): Puzzles are solvable entirely with naked and hidden singles. No advanced techniques required. Ideal for beginners or for a relaxed session.
  • 🤔 Medium (28 clues): Requires naked pairs, pointing pairs, and box-line reduction in addition to singles. A satisfying challenge for regular players.
  • 🧠 Hard (22 clues): Demands X-Wings, Swordfish patterns, and other advanced elimination techniques. Designed for experienced Sudoku solvers.

Notes Mode — The Professional's Tool

Professional Sudoku players never write final answers without first pencilling in candidates — the digits that could potentially go in each cell. On MIA Games, tap the Notes button (or press N) to enter pencil-mark mode. Each cell displays a tiny 3×3 grid of candidates, and you can add or remove individual numbers as your analysis narrows down the possibilities. When you are ready to commit to an answer, exit notes mode and place the digit normally.

Tips and Strategies

  • Scanning: Systematically check each row, column, and box for naked singles before attempting anything more complex.
  • Box elimination: If a digit must appear in one of two rows within a box, it can be eliminated from those rows in other boxes — this is the pointing pair technique.
  • Cross-hatching: Draw imaginary lines through all instances of a digit already placed. The remaining empty cells where a digit can go are often limited to one.
  • Naked pairs: If two cells in the same row, column, or box both contain only the same two candidates, those two digits can be eliminated from every other cell in that row, column, or box.
  • Never guess on Easy or Medium: These difficulties are designed to be solvable purely through logic. If you feel stuck, try the Notes mode and look for newly revealed patterns.

The History of Sudoku

Despite its Japanese name meaning "single numbers," Sudoku was first published in its modern form by American puzzle constructor Howard Garns in 1979, originally titled Number Place in Dell Magazines. The puzzle was introduced to Japan in 1984 by puzzle publisher Nikoli, who gave it the name Sudoku and popularised the format. A retired Hong Kong judge, Wayne Gould, discovered Sudoku in a Tokyo bookshop in 1997 and spent six years writing a computer program to generate puzzles, before pitching it to The Times of London in 2004. From there, the puzzle spread to newspapers worldwide almost overnight, and Sudoku became a global phenomenon. Today it is estimated that over 100 million people solve a Sudoku puzzle every day.