Mini Sudoku is a 6×6 sudoku variant — the same logic as classic 9×9 sudoku, compressed into a smaller grid with digits 1 through 6. Rows, columns, and shaded regions each must contain every digit exactly once. This guide covers the scanning and elimination techniques that make 6×6 boards fast and satisfying.
How 6×6 sudoku differs
| Classic sudoku | Mini Sudoku |
|---|---|
| 9×9 grid | 6×6 grid |
| Digits 1–9 | Digits 1–6 |
| Nine 3×3 boxes | Six irregular shaded regions |
The smaller grid means fewer empty cells per puzzle, but regions overlap rows and columns more tightly — a single placement often unlocks three or four cells at once.
The fundamental scan
For every empty cell, ask: which digits are still legal?
A digit is illegal if it already appears in:
- The same row
- The same column
- The same shaded region
If only one digit fits, place it. This single technique solves most easy and many medium boards without advanced tactics.
Work the overlap
Mini Sudoku regions are not uniform 2×3 blocks — they are irregular shapes that cut across rows and columns. When you place a digit, check all three groups it belongs to:
- Filling a
4in row 2 may eliminate4from three other cells in that row. - The same
4also clears candidates in its column and region.
Experienced solvers pick the row, column, or region with the fewest empty cells and scan that group first.
Hidden singles
Sometimes every empty cell in a row appears to have multiple options — but one digit can only go in one cell in that row. That digit is a "hidden single."
Example: if 3 is missing from row 4 and only cell (4,2) can hold a 3 (because other cells in the row are blocked by column or region constraints), place 3 there even if that cell also allows 5 and 6.
To find hidden singles:
- Pick a row (or column, or region).
- For each missing digit, count how many cells could hold it.
- If the count is exactly one, place it.
Pencil marks (mental or on paper)
On harder boards, track candidate digits for each empty cell. When a placement eliminates a candidate elsewhere, update the list. A cell whose candidates shrink to one digit is ready to fill.
Puzzle Games highlights duplicate digits in red when you enter a conflict — use that feedback to catch mistakes early.
Region-first vs row-first
Two valid approaches:
- Region-first — solve the smallest or most constrained shaded region, then expand.
- Row-first — scan each row for singles and hidden singles top to bottom.
Alternate between them when stuck. A region that seemed blocked often opens after a row scan on the other side of the grid.
Common mistakes
- Forgetting region overlap — a digit legal in the row may still violate the shaded region.
- Guessing too early — Mini Sudoku boards on Puzzle Games are designed to be logic-solvable without guessing.
- Ignoring givens — locked clue cells anchor the grid; build outward from clusters of givens.
Difficulty and practice
| Level | Technique focus |
|---|---|
| Easy | Naked singles, basic scanning |
| Medium | Hidden singles, region overlap |
| Hard | Candidate tracking, cross-group elimination |
Start on easy puzzles, then move to medium and hard when scans feel automatic.
Where to play
- Mini Sudoku how-to-play — rules and controls
- Mini Sudoku demo — sample 6×6 board
- Mini Sudoku archive — dailies and level track
- Random Mini Sudoku — unlimited practice
Mini Sudoku is an excellent gateway to logic puzzles generally — the scanning habits transfer directly to Queens, Tango, and other grid games.