Medium Anti-Consecutive Sudoku

Adjacent cells — horizontally or vertically — cannot contain consecutive digits. Adds a hidden constraint to every placement.

Easy Medium Hard Expert

Anti-Consecutive Sudoku at medium difficulty. Middle digits like 5 block both 4 and 6 in adjacent cells — use this to cascade eliminations through connected regions.

2
1
7
3
8
3
4
9
8
5
1
7
2
6
5
6
8
2
9
1
7
5
8
7
9
2
3
4
9
9
5
4
Mistakes
0/3
Score
-
Time
00:00
Try Hard →
Progress0%

What is Anti-Consecutive Sudoku?

Difficulty
★★★☆☆
3/5
Constraint Type
Anti-Constraints
Typical Givens
18–24
Avg. Solve (Medium)
13 min

Solving Techniques for Medium Level

Technique Description Level
Global Candidate Pruning For every filled cell, remove its ±1 neighbours from all orthogonally adjacent cells immediately. Beginner
Digit 5 is Most Constrained 5 cannot be adjacent to 4 or 6. Use this to restrict placement of 5 across the entire grid. Intermediate
Chain Propagation Placing a digit propagates constraints along rows and columns, often triggering a cascade of forced placements. Intermediate

Master these, then take on Hard Anti-Consecutive Sudoku to learn Advanced techniques.

Average Solve Time by Difficulty

Easy
5 min
Medium
13 min
Hard
26 min
Expert
48 min
Want a full walkthrough of rules, strategies, and solving steps? How to Play Anti-Consecutive Sudoku →

Frequently Asked Questions — Medium Anti-Consecutive Sudoku

What solving techniques help with medium Anti-Consecutive Sudoku?
At medium difficulty, combine naked pairs and hidden singles with consecutive-constraint propagation. The constraint is especially powerful around digits 4, 5, and 6 — placing a 5 eliminates both 4 and 6 from four adjacent cells, creating a wide cone of eliminations.
Why are digits 1 and 9 especially useful in Anti-Consecutive Sudoku?
Digits 1 and 9 each have only one consecutive neighbor (2 and 8). This means they eliminate fewer candidates per placement than middle digits, but it also means they are never restricted by consecutive digits on both sides — they can only be blocked from above or below in the digit sequence. This asymmetry is often exploitable.
What is a consecutive-constraint chain in Anti-Consecutive Sudoku?
A consecutive-constraint chain occurs when placing digit X in cell A eliminates X+1 from adjacent cell B (by the anti-consecutive rule), which forces a different digit into B, which then propagates further via the consecutive rule. Medium puzzles regularly involve chains of three or four such steps.
How do I use pencil marks effectively in medium Anti-Consecutive Sudoku?
Initialize your candidate lists using standard row/column/box elimination, then also remove consecutive neighbors of each given digit from adjacent cells. This extended initialization often produces a denser candidate grid that reveals hidden singles immediately.
How long does a medium Anti-Consecutive Sudoku take?
Most players finish a medium Anti-Consecutive Sudoku in 12–22 minutes. Consistently applying the consecutive constraint during initialization saves significant time compared to discovering eliminations one by one during the solve.

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