Easy Anti-Knight Sudoku

Cells a chess knight's move apart cannot share the same digit. A global constraint that shapes every row and column.

Easy Medium Hard Expert

New to Anti-Knight Sudoku? The knight's-move constraint generates extra eliminations that speed up the solve — apply it after every placement.

8
1
9
7
8
5
6
2
9
1
9
3
5
2
3
7
7
2
6
1
4
1
9
3
3
6
7
4
2
8
3
1
7
5
7
8
3
9
Mistakes
0/3
Score
-
Time
00:00
Try Medium →
Progress0%
♞ Knight's move constraint active

What is Anti-Knight Sudoku?

Difficulty
★★★☆☆
3/5
Constraint Type
Anti-Constraints
Typical Givens
20–26
Avg. Solve (Easy)
5 min

Solving Techniques for Easy Level

Technique Description Level
Knight-Zone Mapping For each cell, mark all potential knight-move destinations (up to 8 cells). None may share the same digit as the source cell. Beginner
Corner and Edge Advantage Corner cells have only 2 knight-move neighbours; edge cells have at most 4. These restricted zones are easiest to resolve first. Beginner

Ready to go deeper? Try Medium Anti-Knight Sudoku to unlock Intermediate techniques.

Average Solve Time by Difficulty

Easy
5 min
Medium
12 min
Hard
24 min
Expert
45 min
Want a full walkthrough of rules, strategies, and solving steps? How to Play Anti-Knight Sudoku →

Frequently Asked Questions — Easy Anti-Knight Sudoku

What is Anti-Knight Sudoku?
Anti-Knight Sudoku adds one rule to standard Sudoku: no two cells that are a chess knight's move apart may contain the same digit. A knight moves in an L-shape — two squares in one direction and one square perpendicular. Any two cells separated by that distance must hold different digits.
How do I apply the knight's-move constraint while solving?
After placing a digit, identify all cells reachable by an L-shaped knight's jump from that cell and remove the digit from their candidate lists. Each cell has up to eight knight's-move neighbors. Applying this elimination consistently is the core skill of Anti-Knight Sudoku.
How is Anti-Knight Sudoku different from Anti-King Sudoku?
Anti-King forbids the same digit in any of the eight cells surrounding a given cell (all neighbors within one step). Anti-Knight forbids the same digit in cells reachable by an L-shaped jump. The knight's neighbors are farther away and non-adjacent, creating a completely different constraint geometry.
Is there anything shown on the board to indicate the knight's constraint?
No — the knight's-move constraint is invisible. The board looks exactly like a regular Sudoku grid. You must mentally track the L-shaped relationships between cells and apply the constraint yourself whenever you place or eliminate a digit.
How do I get started on an easy Anti-Knight Sudoku?
Begin with the standard approach: find rows, columns, and boxes close to completion and use simple elimination. Then augment each elimination by also removing the newly placed digit from all knight's-move neighbors. The extra eliminations often reveal singles very quickly at easy difficulty.

More questions? See the full Anti-Knight Sudoku guide.