Sudoku

About the game

Eighty-one cells, nine small squares of 3x3, and a few digits already sitting in the grid. The rest are blank, and each one needs a number from 1 to 9.

Pick a difficulty, then click an empty cell and click the digit you want. The Notes button lets you pencil in candidates before committing. A digit can appear only once across a row, down a column and inside its own 3x3 square, so every placement narrows the options around it. Wrong entries are easy to make, and a slow scan of the lines beats a fast guess.

How to play

• Click the cell you want to fill, then click a number from 1 to 9 to place it.
• Press Notes to mark possible digits in a cell without placing one.
• Each row, column and 3x3 square must contain every digit exactly once.
• Choose a difficulty level before you start, and watch out for mistakes.