Medium Sudoku — The Everyday Challenge

Medium Sudoku, sometimes called intermediate sudoku, is rated 2.0 to 2.9 on the Sudoku Explainer scale (ER) and is the level most players settle into. Our classic medium grids range from 22 to 40 given digits, 27.8 on average, so the clue count tells you little. With fewer givens than Easy, cells carry more candidates, and scanning alone stops being enough.

What this level asks

Singles still open the grid, then the obvious placements run out. This is the point to switch on notes: write the candidates in a few cells and use them to remove other candidates. Nothing in this band needs a multi-step pattern.

Techniques you will meet

Basic-tier tools do the work. Pointing pairs (rated 2.6) work like this: if a digit is trapped in one line inside a box, it is banned from the rest of that line. Box line reduction (2.8) is the mirror image: a digit trapped in one box by a line is banned from the rest of the box. Naked and hidden pairs rate 3.0 and 3.4 in Sudoku Explainer, so they help at the top of Medium and take over from Hard onwards.

Tips for this level

• Add candidates only to the cells in the unit you are stuck on, not the whole grid.
• When stuck, try the simplest technique you have not tried yet before reaching for a fancier one.
• Check each box, then each row and column, in a fixed order so you do not skip a unit.
• Use a hint instead of guessing. Your game autosaves, so a long solve can span days.

Next step

You are ready for more when pointing pairs and box line reduction feel routine. Hard Sudoku adds fish and wings. Need a refresher on the basics? Go back to Easy.