Easy Sudoku

What an Easy puzzle looks like

Easy puzzles start with 40 to 46 given digits, roughly half the grid. That density matters more than it sounds: with so many digits already placed, most units are one or two placements away from being finished, and each digit you write opens the next one.

The generator only accepts a puzzle as Easy if the solver can finish it without a single elimination step. In practice that means you will always find a cell where one digit is forced — you never have to reason about what a digit cannot be.

The only two moves you need

• Naked single: a cell where eight of the nine digits already appear in its row, column or box, so one digit is left.
• Hidden single: a digit that fits in only one cell of a row, column or box, even though that cell could also hold other digits.

How to scan an easy grid quickly

Work digit by digit rather than cell by cell. Pick the digit that already appears most often on the board, look at the boxes where it is still missing, and cross out the rows and columns it cannot occupy. Usually one square is left.

When that digit runs out of placements, move to the next most common one. This is faster than staring at individual empty cells, and it is the habit that makes harder levels approachable later.

Good for learning, and for a two-minute break

Easy is the level to use when you are teaching someone the rules, when you want a puzzle a child can finish, or when you have a few minutes and want a clean solve instead of a fight. If you find yourself finishing without ever pausing, Medium is the natural next step.