Puzzle skills · Learning guide

Start solving a mini Sudoku

A four-by-four Sudoku uses the same core constraints as its larger cousin, with fewer symbols to track.

Know the constraints

Each row, column and two-by-two box contains 1, 2, 3 and 4 exactly once. Given digits are fixed. A digit that fits a row can still conflict with its box.

Look for missing digits

If a row contains 1, 2 and 3, the remaining cell must be 4. If two cells remain, check their columns and boxes to eliminate possibilities.

Use deductions

Avoid changing a fixed clue to rescue a guess. If you reach a contradiction, revisit your most recent uncertain placement. This mini puzzle has a unique solution.

Further reading: Reference source ↗. Written for this starter collection. Check primary references for specialised use.