Little Killer Sudoku
9
7
6
1
4
3
6
5
9
8
2
7
6
3
4
6
9
2
8
5
7
6
8
1
9
2
3
8
9
6
9
2
3
8
7
2
4
3
Diagonal Clues
↘
from (1,1):
53
(9 cells)
↘
from (1,2):
48
(8 cells)
↘
from (1,3):
38
(7 cells)
↘
from (1,4):
31
(6 cells)
↘
from (1,5):
21
(5 cells)
↘
from (1,6):
21
(4 cells)
↘
from (1,7):
10
(3 cells)
↘
from (1,8):
10
(2 cells)
↘
from (2,1):
23
(8 cells)
↘
from (3,1):
26
(7 cells)
↘
from (4,1):
33
(6 cells)
↘
from (5,1):
26
(5 cells)
↘
from (6,1):
29
(4 cells)
↘
from (7,1):
21
(3 cells)
↘
from (8,1):
5
(2 cells)
↙
from (1,2):
11
(2 cells)
↙
from (1,3):
16
(3 cells)
↙
from (1,4):
19
(4 cells)
↙
from (1,5):
16
(5 cells)
↙
from (1,6):
29
(6 cells)
↙
from (1,7):
35
(7 cells)
↙
from (1,8):
32
(8 cells)
↙
from (1,9):
44
(9 cells)
↙
from (2,9):
51
(8 cells)
↙
from (3,9):
47
(7 cells)
↙
from (4,9):
28
(6 cells)
↙
from (5,9):
22
(5 cells)
↙
from (6,9):
20
(4 cells)
↙
from (7,9):
11
(3 cells)
↙
from (8,9):
10
(2 cells)
How to play Little Killer Sudoku
Standard Sudoku rules apply. The clue list shows diagonal sums - Each entry gives the sum of all cells along that diagonal. The arrow direction (↘ or ↙) and starting cell are shown. Digits may repeat on a diagonal.
Full guide →
Clues outside the grid give the sum of a diagonal
Easy
Little Killer Sudoku Easy
Medium
Little Killer Sudoku Medium
Hard
Little Killer Sudoku Hard
Expert
Little Killer Sudoku Expert
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 type | Outside Clues |
| Typical givens | 0–6 given digits |
| Difficulty rating | ★★★★☆ 4/5 |
| Avg. solve time — Easy | 14 min |
| Avg. solve time — Medium | 28 min |
| Avg. solve time — Hard | 55 min |
| Avg. solve time — Expert | 88 min |
How to Solve Little Killer Sudoku
| Technique | What it does | 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 Times
Easy
14 min
Medium
28 min
Hard
55 min
Expert
88 min
Frequently Asked Questions
What is Little Killer Sudoku?
Little Killer Sudoku is a variant where numbers appear outside the grid next to diagonal arrows. Each clue gives the sum of all cells along the diagonal that arrow points into. Unlike Killer Sudoku cages, digits may repeat along a Little Killer diagonal — the only uniqueness constraints are the standard row, column, and box rules.
How is Little Killer different from Killer Sudoku?
In Killer Sudoku, cage digits cannot repeat. In Little Killer Sudoku, diagonal digits can repeat freely — only standard Sudoku uniqueness rules apply. This changes the solving logic significantly: you cannot directly eliminate combinations based on uniqueness within a diagonal.
Can digits repeat along a Little Killer diagonal?
Yes. Digits may repeat along a Little Killer diagonal as long as they are in different rows, columns, and boxes — which standard Sudoku rules enforce. For example, a 3-cell diagonal summing to 6 could be {1,1,4}, {1,2,3}, {2,2,2}, {3,2,1}, etc.
How do I start solving Little Killer Sudoku?
Start with the shortest diagonals. A 1-cell diagonal tells you the digit directly. A 2-cell diagonal with a very small or very large sum severely limits possible combinations. Then look for diagonals that intersect — where the same cell must satisfy two diagonal sum constraints simultaneously.
Is Little Killer Sudoku hard to learn?
The core rule is straightforward. The challenge comes from the arithmetic of diagonal enumeration combined with the fact that digits can repeat. Beginners benefit from writing out all possible combinations for each diagonal before starting to eliminate. This habit makes the variant much more approachable.
How long does Little Killer Sudoku take to solve?
Easy puzzles take 10–20 minutes. Medium puzzles run 20–40 minutes. Hard puzzles average 40–75 minutes and expert puzzles often exceed 90 minutes. Cross-diagonal intersection analysis is the key skill that distinguishes fast solvers from slower ones.