Sudoku Tips for Beginners: From Stuck to Solving
Here's the secret about sudoku that nobody tells beginners: it has nothing to do with math. No adding, no arithmetic — just the numbers 1 through 9 as symbols. You could play it with nine different emojis and it would work exactly the same. Sudoku is a logic puzzle, and logic is a skill you build one technique at a time. These three techniques will carry you through every easy and medium puzzle ever made.
First, the only rule
Fill the 9×9 grid so that every row, every column, and every 3×3 box contains the digits 1–9 exactly once. That's it. Everything in sudoku is just this rule applied cleverly.
1 Scanning: the technique that solves half the puzzle
Pick a number — say, 7. Now sweep the grid and look at every 7 that's already placed. Each one "blocks" its row, column, and box from containing another 7. Often you'll find a box where the 7 can only go in one remaining cell, because the other spots are blocked. Fill it in, and repeat. Do this for 1 through 9, then loop again — each number you place creates new scanning opportunities. Beginners are shocked how far pure scanning gets them: on easy puzzles, sometimes the whole grid.
How to practice: go slowly, one number at a time, and physically (or mentally) trace the blocked lines. Speed comes later; accuracy first.
2 Pencil marks: your scratch paper
When scanning stalls, write small "candidate" numbers in each empty cell — every digit that could still go there. Yes, it's tedious the first time. But candidates turn an invisible puzzle into a visible one: suddenly you can see the logic instead of holding it all in your head. Most apps (including our Daily Sudoku) have a notes mode that does this for you. Use it shamelessly — even experts do.
Here's the payoff: once candidates are in, scan each row, column, and box for a cell that has only one candidate left. That's a guaranteed placement. Fill it, erase the candidates it kills elsewhere, and repeat. This alone solves most medium puzzles.
3 The hidden single: your first "advanced" move
Sometimes a row has five empty cells, and the number 4 appears as a candidate in four of them — but in the fifth cell, 4 is the only candidate... wait, that's just a single. Here's the sneaky version: look at a row and ask "where can 4 go in this row?" If four of the five empty cells already have 4 blocked (by column or box rules), then the fifth cell must be 4 — even if that cell has other candidates written in it. The 4 was "hidden" among other candidates. Spotting hidden singles is the moment beginners become intermediate solvers. It feels like a superpower the first time.
Three beginner traps to avoid
"I should guess when I'm stuck." Never guess on easy/medium puzzles — a proper sudoku always has a logical next move. Guessing teaches you nothing and usually forces a restart. If you're truly stuck, you missed a scan; take a break and look again with fresh eyes.
"I need to be fast." Speed is a byproduct of pattern recognition, which only comes from slow, careful solving. The person who finishes in 4 minutes once solved hundreds of puzzles slowly first.
"Hard puzzles need fancy techniques." Not at first. Most "hard" daily puzzles still fall to scanning + candidates + hidden singles if you're thorough. Fancy techniques (X-wings, swordfish) are for genuinely diabolical puzzles — you'll know when you're ready because the basics will feel automatic.
A 10-minute practice routine
- Days 1–3: Solve easy puzzles using only scanning. No candidates. Build the habit of systematic sweeping.
- Days 4–7: Add pencil marks when scanning stalls. Notice how the puzzle "opens up".
- Week 2: Hunt specifically for hidden singles — one puzzle a day where that's your only goal.
- Week 3+: Move to medium difficulty. It'll feel hard for two days, then suddenly... not.
The daily format is perfect for this: one puzzle a day is enough to build the skill without burning out. Play today's Daily Sudoku, start with scanning, and give yourself permission to be slow. Every expert was once someone staring at an empty grid wondering where to begin.