Little Killer Sudoku

Clues outside the grid give the sum of a diagonal

What is Little Killer Sudoku?

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.

At a Glance

Constraint typeOutside Clues
Typical givens0–6 given digits
Difficulty rating ★★★★☆ 4/5
Avg. solve time — Easy14 min
Avg. solve time — Medium28 min
Avg. solve time — Hard55 min
Avg. solve time — Expert88 min

How to Solve Little Killer Sudoku

TechniqueWhat it doesLevel
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 Times

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.