Sudoku for Absolute Beginners: Your First Ten Puzzles

Almost everyone who quits sudoku quits in their first three puzzles. Not because the puzzle is too hard, but because nobody told them what to expect, what to look at first, or how long it should take. This is the guide I wish I'd had when I started.

The plan is simple: ten puzzles, all at easy difficulty, played over a week or two. By the tenth one you'll finish without hesitation, and you'll be ready for medium. Here's what to do in each of those first ten games.

Before puzzle one: a small mental setup

Two things to know before you place your first digit. They will save you the most common new-solver frustration.

First: you don't need to be good at maths. The digits in a sudoku are just labels. Nothing gets added or multiplied. If the grid used letters or coloured shapes, the puzzle would be exactly the same.

Second: you never have to guess. Every move has a reason. If you're tempted to try a digit just to see what happens, slow down. You've missed a clue, not run out of road.

"Sudoku is not a maths test. It's a looking puzzle. You're looking for cells where the answer is already forced by what's on the grid."

Puzzles 1 and 2: just play, then read this again

For your first two puzzles, all you're doing is getting used to what an empty sudoku looks like and where your eyes naturally go. Don't time yourself. Don't worry about technique. If a puzzle takes you forty minutes, fine. If you get stuck for ten minutes, fine.

The only rule for these two: place a digit only when you're sure. If you place a wrong digit and don't notice, the whole puzzle goes sideways twenty cells later, and that's when most new solvers give up. Slow placements, fast verification.

Need a grid? Start an easy puzzle and come back to the next section after you've done two.

Puzzles 3 and 4: learn the box scan

The single most useful move a new solver can learn is the box scan. It works like this: pick a digit, say 5. Find every 5 already on the grid. Now look at the nine 3×3 boxes. For any box that doesn't yet have a 5, ask: which cells in this box could still be a 5, given the rows and columns of existing 5s?

Often the answer is one cell. Place the 5 there. Move on to the next digit.

Run this for all nine digits, in order, before moving on. On an easy puzzle, you'll place fifteen or twenty digits without using anything fancier. By the end of puzzle 4, this should feel automatic.

Puzzles 5 and 6: spot the "only place left" cell

By now you'll have noticed that some cells have very few options. Some have only one. When a cell has only one possible digit, place it. That's called a naked single, and it's the second move you'll add to your repertoire.

The way to find them: look at any empty cell on the grid. Glance at its row, its column and its 3×3 box. List the digits that are already taken. If eight digits are taken between the three groups, the ninth one belongs in that cell.

Don't try to find every naked single before you start the box scan. Use the two together. Often a placement from the box scan creates a new naked single, which leads to another placement, which leads to another. Cascades are how easy puzzles get finished.

Puzzles 7 and 8: keep moving when you stall

Halfway through an easy puzzle, you'll hit a moment where neither the box scan nor the naked-single check seems to be working. This is the moment most new solvers panic.

Don't. The right move is to keep cycling. Go back to digit 1 and scan again. Then 2. Then 3. The grid has changed since the last time you looked. Placements you've made have opened up new constraints. A box that had two candidates for 4 might now have one.

1. 1
   Pick a digit, any digit

   Start with 1, 5 or 9. They tend to be the most constrained on a typical puzzle.
2. 2
   Find every existing instance on the grid

   Glance at the whole grid. Note which boxes already contain it.
3. 3
   Look at every box that doesn't have it yet

   For each of those, ask: which cells could legally hold this digit?
4. 4
   Place wherever there is only one option

   If a box has only one candidate cell for the digit, that's the placement.
5. 5
   Move to the next digit and repeat

   Until you've cycled all nine digits. Then start again at 1.

On an easy puzzle, two or three passes through this loop will finish the grid. If after three passes nothing has moved, walk away for a few minutes. Come back. The miss will be obvious.

Puzzles 9 and 10: build the habits that last

By now you've finished six or seven easy puzzles. The next two are about cementing habits, not learning techniques. Here is the short list:

• ✓Trust the puzzle. Reputable easy puzzles always have a logical solution.
• ✓After every placement, glance at the digit's row, column and box. If you have stale pencil marks, sweep them.
• ✓Don't switch difficulty. Stay at easy until you can finish one in under ten minutes.
• ✓Don't watch the clock while you play. Glance after you finish.
• ✓If you place a wrong digit, undo the move calmly. Don't tear the puzzle up.

What to expect at each milestone

If by puzzle 10 you still need thirty minutes for an easy puzzle, don't move up. Do five more. Patience here costs nothing and prevents a frustrating jump that would have you bouncing back.

Things you do not need yet

Almost everything you'll read about sudoku assumes you're chasing hard puzzles. For your first ten games, you can ignore all of it. Specifically:

• Pencil marks. Writing tiny candidate digits in empty cells is essential for hard puzzles. It's a waste of time on easy ones. Skip it.
• Pointing pairs, X-wings, swordfish. These are all real techniques. None of them appear in easy puzzles. You'll learn them when the puzzles demand them.
• Timers. Time yourself if you're curious, but don't optimise for speed yet. Speed comes from pattern recognition, which comes from repetition.
• Stopping mid-puzzle. Finish what you started. Even if the puzzle takes an hour, the act of finishing teaches you something that stopping doesn't.

What "ready for medium" feels like

You'll know you're ready to move up when an easy puzzle stops being interesting. Most cells fall in one move. The box scan feels automatic. You finish without thinking very hard. That's the signal.

When that happens, switch to medium puzzles. They have fewer starting clues, and the box scan alone won't finish them. That's where you'll start to learn the next technique, the hidden single, which the hidden singles strategy page covers in detail.

One last thing

Sudoku rewards consistency more than intelligence. People who play one puzzle a day for a month always pass people who play ten in one binge and then stop. The cognitive habits compound between sittings, not within them.

So: pick up your first puzzle now. Aim to do one a day for the next ten days. If you'd like a printed version to do over coffee, the printables page has free PDF packs. Or, if you prefer to stay on screen, start puzzle one now and see how it feels.

Once you've finished ten, come back and read the full solving guide. It will make more sense after the practice than before.