Alphabet / Word Sudoku
Uses letters instead of numbers — and often spells a word in one row
Alphabet / Word Sudoku is fully playable. Choose a difficulty and start solving.
Letters A–I replace the digits, and nothing else changes: one of each letter per row, column, and box. With no numeric instincts to lean on, you solve by pure presence-and-absence reasoning. Same depth as the number version, slightly slower visual scanning.
For the complete rules, worked examples and solving techniques, read the full How to Play Alphabet / Word Sudoku guide.
Like all Sudoku variants, Alphabet / Word Sudoku builds on the classic 9×9 foundation. Every row, column, and 3×3 box must contain each digit from 1 to 9 exactly once. The variant constraint is added on top of these standard rules, never replacing them.
If you're new to Sudoku, start by learning the basic rules and techniques before attempting variants.
Techniques Useful for This Variant
| Technique | How it applies |
|---|---|
| Pencil Marks / Notes | Essential for tracking candidates alongside the variant constraint |
| Obvious Singles | Cells narrowed to one candidate by the combined constraints |
| Hidden Singles | Digits with only one valid cell in a unit after variant elimination |
| Pairs and Triples | Locked candidates exposed by the additional constraint |