Sudoku tips for beginners

Sudoku can feel overwhelming at first, because every empty cell seems to depend on every other one. The good news is that a few steady habits solve most of that feeling. The twelve tips below work at any level.

Twelve tips for beginners

1. Read the rules once, slowly. Each row, column and box holds the digits 1 to 9 exactly once. Most mistakes come from forgetting one of the three units.

2. Start with the fullest units. A row, column or box with many givens has fewer empty cells, so there are fewer places to check and the logic is easier to see.

3. Scan one digit at a time. Pick a digit, such as 5, and find every place it can go. This is often more reliable than scanning cell by cell.

4. Use cross-hatching. When a digit is missing from a box, look at the rows and columns that already hold it. The patterns are explained below.

5. Look again after every placement. A new digit removes a candidate from its row, column and box. One of those cells may now have only one candidate left.

6. Add notes only where you need them. Early on, a few notes in the hard cells are enough. Add more as the grid fills and you need a clearer picture.

7. Let Hush keep your notes tidy. Hush’s notes clean themselves up when you place a number, and “fill in all notes” adds every candidate in one step when you want a full picture.

8. Use the highlights. Hush highlights your row, column, box and matching numbers. Matching numbers show you every copy of a digit at a glance.

9. Do not guess. Every puzzle in Hush can be solved by logic alone. If you feel you must guess, step back and check a unit you have not looked at yet. Undo lets you retrace a step without any penalty, because Hush has no mistake limit.

10. Take a break when you are stuck. A fresh look often shows the move you missed. Pausing is always possible, and the game is saved.

11. Learn one technique at a time. Master naked and hidden singles before you move on to locked candidates or pairs.

12. Play a little every day. The daily puzzle is the same for everyone and always free. On Monday to Thursday it is a Medium puzzle, and on Friday to Sunday it is a Hard puzzle. If a day feels too hard, play an Easy puzzle instead.

Two patterns to look for

Cross-hatching

Cross-hatching is a way to scan one digit inside one box. Take an empty box and a digit that is missing from it. Look at the rows and columns outside the box. Any row or column that already holds that digit cannot hold it inside the box. Whatever cells are left are where the digit can go.

Here the center box is rows 4 to 6 and columns 4 to 6. The 3s at r4c8 and r5c2 block rows 4 and 5, and the 3s at r1c5 and r8c4 block columns 5 and 4. The cells marked - are ruled out for 3 because each sees one of these 3s. The only cell left is r6c6, so the 3 goes there.

When a digit is placed eight times

If eight copies of a digit are already on the board, the ninth copy has only one place left. The picture shows eight 4s, placed so that no two share a row, column or box.

Rows 1 to 8 each already hold a 4, so the last 4 must go in row 9. Columns 1 to 4 and 6 to 9 each hold a 4, so the last 4 must go in column 5. The only cell that is in row 9 and column 5 is r9c5. Look for this pattern whenever a digit appears often on the board.

A routine for your first week

You do not need to master everything at once. A simple week might look like this:

• Days one and two. Play Easy puzzles only. Focus on tips 1, 2 and 5, and check every unit after each placement.
• Days three and four. Add cross-hatching from tip 4. When you get stuck, look for a digit with few places and scan it across the grid.
• Days five to seven. Try a Medium puzzle or the daily puzzle. Use notes for the cells you cannot settle, and let Hush keep them tidy as you place numbers.

Keep a note of the moves that confused you. Those are the techniques to learn next. The Learn hub lists every technique in order, from singles to the advanced fish and wing patterns, so you always know where you are heading. Hush’s home page describes the app and its levels in one place.

Practice these habits in Hush

Easy puzzles in Hush use only singles, so these habits are enough to start with. Easy and Medium puzzles are unlimited and free, and the daily puzzle is free every day. Your notes, highlights and undo are all there to help you use these habits, and you can pause whenever you need a break. Many players find that the habits matter more than any single trick, so give yourself time to build them. When you are ready for more, how to solve sudoku explains the rules and singles in full, and Expert sudoku shows where the hardest techniques are used. If you play on the go, offline sudoku explains how every puzzle ships with the app.