Welcome to Bob’s Squiggly Sudoku/Du-Sum-Oh Puzzle Page

How To Solve One of These Puzzles
Puzzle Choices
Halloween Squigglies
Squiggly Sudoku puzzles are also known as Latin Squares Puzzles (invented by Mark Thompson), Du-Sum-Oh, Jigsaw Sudoku, Irregular Sudoku, or Geometric Sudoku. Your goal is to fill a square grid with letters so that each row contains every letter exactly once. Each column must also contain every letter once, and so must every region. Several letters are given to start you off.

A sample squiggly is shown below left. The solution is on the right.


The puzzles presented at this website are much stingier with starting hints than those at Sudoku sites. For an NxN puzzle, I usually present only puzzles with N or N-1 hints. Each row, column, or region contains no more than one hint, and no letter appears more than once among the hints. All puzzles here are uniquely solvable. Except as indicated for some of the 9x9s, only simple logic is needed (no guesses or what-if conjectures are required).

In contrast to traditional Sudoku, the geometry of the puzzle gives you additional information that makes up for the shortage of starter hints. See the tutorials for how to make use of this information.

  5x5 Squigglies
5 hints   4 hints Dec/26/2005
  6x6 Squigglies 6 hints   5 hints Dec/27/2005
  7x7 Squigglies 7 hints   6 hints May/25/2006
  8x8 Squigglies 8 hints   7 hints Dec/26/2005
                 9x9 Squigglies 9 or 8 hints Nov/11/2005

  Happy Easter Squigglies Apr/14/2006
  Halloween Squigglies Oct/6/2006
  Thanksgiving Hidden Squigglies Nov/20/2007
  Santa Claus Squigglies Dec/23/2005
                 Christmas Hidden 7x7 Squiggly Nov/25/2006
  Christmas Hidden Squigglies Dec/15/2007
    More Christmas Hidden Squigglies Dec/23/2010
5x5 Squiggly Tutorial Sep/28/2005
7x7 Squiggly Tutorial Sep/28/2005
8x8 Squiggly Tutorial Sep/28/2005

  Bumble Beagle Squigglies Dec/23/2005
                 Double Du-Sum-Oh Jan/30/2007
                 7x7 Rooftop Lights Dec/2001

Older Puzzles
Older 6x6 Squigglies Oct/7/2005
Older 7x7 Squigglies Oct/2/2005
Older 8x8 Squigglies Oct/3/2005

Related Stuff
A proof that an N-1 hint Du-Sum-Oh exists for any NxN Mar/26/2006
A brief history of Latin Squares Puzzles

To celebrate the appearance of one of my puzzles in the June/2006 issue of Scientific American, I created a book of 120 new puzzles: Squiggly Sudoku.

The book contains a range of sizes from 5x5 to 9x9. Difficulty levels are from easy (with extra hints, making them easier than puzzles here at the website) to hard (with N-1 hints up through 8x8).