Expert Little Killer Sudoku

The ultimate test. Expert Little Killer Sudoku puzzles push the variant constraint to its limit, requiring flawless logic and the most advanced solving techniques. Only the sharpest minds complete these.

▶ Play Expert Little Killer Sudoku All Little Killer Sudoku Difficulties

What to expect at Expert level

Expert Little Killer Sudoku puzzles are constructed to be as difficult as possible while remaining logically unique. Every cell placement flows from precise reasoning - Guessing never helps. The constraint creates complex cross-cell dependencies that demand full concentration.

Designed for solvers who have mastered Hard and are looking for the definitive Little Killer Sudoku experience.

Difficulty overview

LevelCluesTechniques neededAvg. time
Easy ManyBasic elimination5–10 min
Medium ModerateSingles, pairs10–20 min
Hard FewAdvanced logic20–40 min
Expert MinimalFull mastery40+ min

About Little Killer Sudoku

Difficulty
★★★★☆
4/5
Constraint Type
Outside Clues
Typical Givens
0–6 given digits
Avg. Solve (Expert)
88 min

Little Killer Sudoku places clues outside the grid along with a diagonal arrow. The arrow points to a diagonal stripe of cells, and the clue gives the sum of all digits along that diagonal. Unlike standard Killer Sudoku cages, digits CAN repeat on Little Killer diagonals as long as they don't violate the row/column/box rules. This makes the arithmetic different from standard cage solving.

Solving Techniques for Expert Level

Technique Description Level
Diagonal Enumeration For each clue, enumerate all combinations of N digits (allowing repeats, 1–9) that sum to the clue value. Beginner
Repeating Digits Allowed Unlike Killer cages, Little Killer diagonals can repeat digits as long as standard row/column/box uniqueness is preserved. Beginner
Short Diagonal Logic A 1-cell diagonal directly gives that cell's digit. A 2-cell diagonal with clue C has limited pairs — enumerate them immediately. Intermediate
Cross-Diagonal Intersection When two diagonals share a cell, the shared cell must satisfy both sum constraints simultaneously. Advanced
Row/Column Interaction A diagonal cell belongs to a row, column, and box — combine Little Killer sum constraints with standard uniqueness rules. Intermediate

Average Solve Time by Difficulty

Easy
14 min
Medium
28 min
Hard
55 min
Expert
88 min

Frequently Asked Questions

What is a 'diagonal' here?
A Little Killer diagonal is a sequence of cells running diagonally from an outside arrow clue, in the direction indicated by the arrow.
Can the sum repeat any digit?
Yes — digits can repeat on a Little Killer diagonal, unlike Killer cages.
Are given digits provided inside the grid?
Some puzzles include a few given digits; others provide only the outside clues.