Looking for a new challenge? Check out my latest additions: Suguru, Futoshiki, Samurai Sudoku, Emoji Doku, Krypto Inkies, and Battleships!

# Killer Sudoku Puzzles

Killer Sudoku (also called Sum Sudoku) are a kind of hybrid puzzle that combine the best features of Sudoku and Kakuro (cross-sum) puzzles. Like a regular Sudoku, the rows, columns and 3x3 blocks contain the digits 1 thru 9. In addition, the dotted lines indicate areas, called cages, which also contain a set of non-repeating digits. If you add up the digits in a cage, you get the sum shown in its clue.

My Killer Sudoku puzzles are collected in 100 printable booklets per volume. Within each volume, the puzzles are also ordered by ascending difficulty (book 100 is harder than book 1, but book 1 volume 9 is about the same as book 1, volume 1). Each booklet contains eight puzzles, instructions, and answers.

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

Need a cheat sheet? Print out this one-sheet of candidate cage sets which makes it easier to eliminate numbers.

## Select a difficulty level:

Wait, didn't I just say the Super-Tough puzzles were the toughest I make? Well, I must be insane, because these new ones are actually even harder.
Insane Killer Sudoku, Volume 1
Insane Killer Sudoku, Volume 2
Insane Killer Sudoku, Volume 3
Insane Killer Sudoku, Volume 4
Insane Killer Sudoku, Volume 5
Insane Killer Sudoku, Volume 6
Insane Killer Sudoku, Volume 7

## How to use the hints

My puzzles contain a page of hints in addition to a page of answers.

The hints are puzzles grids that contain numbers showing the order in which the squares were solved by the computer. Although this is not necessarily the order you would solve the puzzle, it's probably pretty close.

Follow the numbered squares in order 1,2,3,4,5... until you find a square you haven't solved yet. This square (or the one or two immediately after it) is a good candidate to solve next.