The first time I tried Sudoku I stared at the grid, got two numbers in, and gave up convinced I needed to be good at math. That was completely wrong. Sudoku has nothing to do with arithmetic, it is a logic puzzle where the digits could just as easily be nine different colors. Once I learned a few beginner strategies, I went from quitting halfway to finishing easy puzzles in a few minutes. Here are the exact techniques that got me there, in the order I actually use them.
The one rule that drives everything
Sudoku is a 9 by 9 grid split into nine 3 by 3 boxes. Each row, each column, and each box must contain the digits 1 through 9 with no repeats. That single rule is the whole game. Every strategy below is just a smart way of asking the same question: where is the only place a number can legally go?
Strategy one: scan for the obvious
I always start by scanning rows, columns, and boxes for numbers that are already crowded. If the digit 5 already appears in seven of the nine boxes, the last two are usually easy to place. I look at where 5 lives in nearby rows and columns, then cross those lines out in my head. Often only one empty cell in a box can possibly hold that 5. Drop it in and move to the next digit.
Work one number at a time
Beginners try to solve cell by cell and get overwhelmed. I solve digit by digit instead. I pick a number, hunt it across the whole grid, place everywhere it clearly fits, then move to the next number. This is far less tiring and surfaces easy wins fast.
Strategy two: the single candidate
Sometimes a single empty cell can only hold one possible digit because the other eight are already blocked by its row, column, and box. When I find a cell where eight of the nine digits are ruled out, the ninth is forced. These forced cells are the backbone of every easy puzzle, and finding one usually unlocks several more around it.
Strategy three: pencil marks
When scanning stops giving easy answers, I switch to pencil marks. In each empty cell I jot the small list of digits that could still go there. Most online versions, including the one I play, have a notes mode for exactly this. Pencil marks turn an invisible problem into a visible one. Suddenly you spot cells with only one candidate left, and you spot pairs of cells in a box that share the same two candidates, which locks those digits out of every other cell in that group.
- Naked single: a cell with only one pencil mark left. Fill it in.
- Hidden single: a digit that appears as a candidate in only one cell of a row, column, or box, even if that cell has other marks. It must go there.
Strategy four: never guess on easy puzzles
Real beginner and easy Sudoku puzzles always have a logical next step. If you feel like you have to guess, you have almost certainly missed a scan somewhere. I take a breath, recheck each digit across the grid, and the move is usually hiding in plain sight. Guessing leads to mistakes that cascade and force you to restart, so I treat it as a sign to slow down rather than gamble.
A simple beginner routine
Here is the loop I run on every easy grid. Scan each digit 1 through 9 for obvious placements. Fill what you can. When that dries up, add pencil marks to the remaining cells. Look for naked and hidden singles. Repeat until the grid is full. That routine alone clears the vast majority of beginner puzzles without any advanced technique.
Practice on a free grid right now
The only way these strategies stick is by doing them, so open the free Sudoku game and start on an easy board. It runs in your browser with no download and has a notes mode for pencil marks. Solve one slowly using the routine above, then try to beat your time on the next. If you enjoy this kind of pure deduction, you will likely also love Minesweeper for its number-reading logic, or a relaxed round of Word Search when you want something lighter.