Puzzle Cottage
Puzzles
Hard #1
Puzzle 1 of 12
1
8
1
3
4
5
9
3
1
6
1
8
7
1
3
7
8
8
4
7
5
8
6
5
7
Hard #2
Puzzle 2 of 12
7
4
3
9
7
9
2
1
9
4
3
8
6
5
1
7
9
5
7
4
6
5
2
2
6
Hard #3
Puzzle 3 of 12
3
4
8
1
6
5
3
1
2
4
5
7
8
6
3
5
9
8
7
8
7
9
4
7
6
Hard #4
Puzzle 4 of 12
5
3
1
2
2
3
9
8
5
3
9
7
2
6
3
8
1
6
4
5
8
1
1
9
8
Hard #5
Puzzle 5 of 12
6
2
7
8
9
1
3
5
4
8
4
9
4
7
3
6
5
9
1
3
7
5
6
9
7
Hard #6
Puzzle 6 of 12
9
7
1
2
6
8
4
9
5
2
1
3
5
8
6
1
8
8
9
7
1
4
4
2
9
Hard #7
Puzzle 7 of 12
9
5
1
6
8
9
4
2
5
6
1
6
3
4
1
7
3
9
5
8
9
5
3
3
9
Hard #8
Puzzle 8 of 12
6
8
9
1
7
6
9
8
2
8
9
6
1
3
5
9
7
4
5
4
7
1
1
5
9
Hard #9
Puzzle 9 of 12
6
4
7
2
5
6
7
9
7
3
2
8
1
7
4
8
6
9
3
7
8
8
7
4
2
Hard #10
Puzzle 10 of 12
6
7
7
1
8
4
4
6
1
6
5
7
9
1
6
4
2
8
7
9
7
6
9
7
9
Hard #11
Puzzle 11 of 12
8
7
1
8
4
9
5
3
8
3
5
7
4
7
5
6
5
1
8
5
4
7
6
1
4
Hard #12
Puzzle 12 of 12
8
4
6
8
1
7
6
8
2
5
7
3
8
1
8
7
6
5
2
4
7
2
8
1
5
Answer key
Hard #1 — solution
Answer 1 of 12
3
1
4
8
5
6
2
7
9
2
7
8
1
3
9
4
5
6
9
5
6
4
2
7
3
8
1
6
9
1
3
8
2
7
4
5
4
8
7
5
9
1
6
3
2
5
3
2
7
6
4
1
9
8
7
2
3
9
1
8
5
6
4
1
4
9
6
7
5
8
2
3
8
6
5
2
4
3
9
1
7
Hard #2 — solution
Answer 2 of 12
2
1
5
7
4
8
3
6
9
6
8
4
1
9
3
5
2
7
9
3
7
5
6
2
1
4
8
7
2
1
8
5
9
4
3
6
8
9
3
4
2
6
7
1
5
5
4
6
3
1
7
8
9
2
3
5
2
6
7
4
9
8
1
1
6
8
9
3
5
2
7
4
4
7
9
2
8
1
6
5
3
Hard #3 — solution
Answer 3 of 12
3
5
1
9
4
2
6
7
8
9
2
8
1
7
6
5
3
4
7
4
6
8
5
3
2
1
9
1
7
2
6
9
8
3
4
5
5
9
4
3
2
7
1
8
6
6
8
3
5
1
4
9
2
7
2
6
9
4
8
1
7
5
3
8
1
5
7
3
9
4
6
2
4
3
7
2
6
5
8
9
1
Hard #4 — solution
Answer 4 of 12
5
3
4
8
7
1
6
2
9
7
2
6
5
3
9
4
1
8
8
1
9
6
4
2
5
7
3
6
4
5
3
2
8
1
9
7
9
7
2
1
5
4
8
3
6
3
8
1
7
9
6
2
4
5
2
5
3
4
6
7
9
8
1
4
6
8
9
1
3
7
5
2
1
9
7
2
8
5
3
6
4
Hard #5 — solution
Answer 5 of 12
3
5
6
9
4
2
7
1
8
9
1
7
3
6
8
5
4
2
2
4
8
7
1
5
6
3
9
6
8
2
1
5
9
3
7
4
5
3
1
2
7
4
9
8
6
4
7
9
6
8
3
2
5
1
7
6
4
5
9
1
8
2
3
8
9
3
4
2
7
1
6
5
1
2
5
8
3
6
4
9
7
Hard #6 — solution
Answer 6 of 12
2
9
5
7
8
3
1
4
6
7
4
1
5
6
9
2
3
8
3
6
8
1
2
4
7
5
9
8
5
7
4
9
2
6
1
3
1
3
9
6
5
8
4
2
7
4
2
6
3
7
1
8
9
5
6
1
3
9
4
7
5
8
2
9
7
2
8
1
5
3
6
4
5
8
4
2
3
6
9
7
1
Hard #7 — solution
Answer 7 of 12
7
6
3
5
9
8
1
4
2
4
5
2
7
3
1
6
9
8
8
9
1
6
4
2
5
7
3
6
3
7
4
5
9
8
2
1
5
1
9
2
8
6
7
3
4
2
8
4
1
7
3
9
6
5
1
7
5
3
6
4
2
8
9
9
4
6
8
2
5
3
1
7
3
2
8
9
1
7
4
5
6
Hard #8 — solution
Answer 8 of 12
9
5
3
2
4
8
6
1
7
2
6
8
7
5
1
3
4
9
4
1
7
6
9
3
8
5
2
3
8
5
9
6
4
2
7
1
6
9
1
8
2
7
4
3
5
7
2
4
1
3
5
9
8
6
1
3
6
5
8
9
7
2
4
5
4
9
3
7
2
1
6
8
8
7
2
4
1
6
5
9
3
Hard #9 — solution
Answer 9 of 12
3
9
6
8
4
5
2
1
7
7
4
2
9
6
1
3
5
8
8
1
5
3
2
7
9
6
4
6
2
1
7
5
9
8
4
3
5
7
8
6
3
4
1
9
2
4
3
9
2
1
8
5
7
6
1
5
7
4
8
2
6
3
9
2
6
4
1
9
3
7
8
5
9
8
3
5
7
6
4
2
1
Hard #10 — solution
Answer 10 of 12
6
1
3
8
4
2
5
7
9
5
9
2
7
3
1
6
8
4
4
7
8
6
5
9
3
1
2
2
6
1
3
7
5
4
9
8
7
8
9
1
6
4
2
5
3
3
4
5
2
9
8
7
6
1
9
2
4
5
1
7
8
3
6
8
5
6
9
2
3
1
4
7
1
3
7
4
8
6
9
2
5
Hard #11 — solution
Answer 11 of 12
6
9
3
1
8
5
2
7
4
7
1
8
4
9
2
3
5
6
2
5
4
6
3
7
9
1
8
3
2
5
8
7
9
4
6
1
4
7
1
3
5
6
8
9
2
8
6
9
2
1
4
5
3
7
5
4
6
9
2
1
7
8
3
1
3
7
5
4
8
6
2
9
9
8
2
7
6
3
1
4
5
Hard #12 — solution
Answer 12 of 12
5
2
8
9
3
4
1
7
6
3
6
9
2
1
7
8
5
4
1
7
4
5
6
8
9
2
3
2
8
3
1
4
6
5
9
7
6
5
7
3
9
2
4
8
1
4
9
1
8
7
5
6
3
2
8
1
6
7
5
3
2
4
9
9
3
5
4
2
1
7
6
8
7
4
2
6
8
9
3
1
5
Frequently asked questions
How hard is Hard Sudoku?
56 blanks per puzzle (25 clues). Requires multiple intermediate techniques: pencil marks, naked/hidden pairs, pointing pairs, sometimes X-wings. Average solve time: 15–25 minutes.
What techniques do I need?
Beyond scanning and hidden singles, you'll need: naked pairs, pointing pairs, X-wing pattern recognition. See Sudoku tips when stuck for worked examples.
Are these competition-grade?
These are challenging but not Expert-grade. Tournament Sudoku uses additional techniques (swordfish, XY-wing, forcing chains) that aren't required here.
Are these really free?
Yes. Free to print, free to save as PDF.
Stuck on a Hard puzzle — what do I do?
Three steps: re-scan for missed naked singles, fully pencil-mark every empty cell, then look for X-wing patterns. Past 15 minutes stuck, restart from scratch — you've probably made an error.