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 `4` in row 2 may eliminate `4` from three other cells in that row.
- The same `4` also 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:

1. Pick a row (or column, or region).
2. For each missing digit, count how many cells could hold it.
3. 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](/easy-puzzles), then move to [medium](/medium-puzzles) and [hard](/hard-puzzles) when scans feel automatic.

## Where to play

- [Mini Sudoku how-to-play](/mini-sudoku/how-to-play) — rules and controls
- [Mini Sudoku demo](/mini-sudoku/demo) — sample 6×6 board
- [Mini Sudoku archive](/mini-sudoku/archive) — dailies and level track
- [Random Mini Sudoku](/mini-sudoku/random) — unlimited practice

Mini Sudoku is an excellent gateway to [logic puzzles](/logic-puzzles) generally — the scanning habits transfer directly to Queens, Tango, and other grid games.