March 17: I've added Novice Sudoku puzzles (which sit between Easy and Intermediate), making seven levels of Sudoku difficulty to choose from. One for each day of the week!

Challenging Killer Sudoku, Volume 1

Each booklet contains a collection of eight different puzzles, 1-per-page, with a page of answers in the back. The booklets are ordered by ascending difficulty -- the puzzles in book 100 are much harder than the puzzles in book 1. All these puzzles have a single unique solution.

These puzzles are in PDF format and need the Adobe Acrobat Reader to view or print. If you like these puzzles, also check out my other puzzles.

Want to save some trees? Try the online version of these puzzles.

I've created a potentially useful one-sheet of candidate cage sets which makes it easier to eliminate numbers.

Problems printing puzzles? Try these work-arounds.

Out of Challenging puzzles? Here's 800 more!.

All puzzles ©2005-2014 KrazyDad.com. Feel free to reproduce the puzzles for personal, church, or school use. If you would like to purchase new puzzles for a book or periodical, contact me at dad@krazydad.com.