For me, before I discovered Sudoku there was Paint By Numbers (Nonograms). I was particularly fascinated by painting (shading actually) logically. There are three books of Paint By Numbers Puzzles that I’m aware of: one is authored by Games Magazine, called Paint By Numbers and the other two are by Kathy Weaver, called Art Puzzles By Number and More Art Puzzles By Number.

## Battleship Sudoku

Two games in one: Battleship and Sudoku. There are fewer Sudoku clues and added Battleship clues. Use both sources to solve both objectives. The battleships in the fleet are either horizontal or vertical and are totally non-adjacent to each other. The border numbers show the number of cells in a row or column that are contained on one or more battleships.

This variant stems from the 2007 Sudoku Championship Puzzle Instruction Book (in pdf format)

## Sudoku Puzzle Creation

When your spiffy Computerized, Programmatic Sudoku Puzzle Generator is not available, consider the low-technology, self-involving, self-sufficient random number generator and cell locator tools. You need at least 17 starting numbers and symmetry is required only for the obsessive compulsive (or Virgo people). Don’t start with too many numbers, though, unless creating unsolvable puzzles is your goal.

## Geometric Sudoku

A mapping of Geometric Shapes For Sudoku Purposes. Each n-gon shape contains the number of sides corresponding to its units digit.

## Shogi Sudoku

I have been a long time Shogi (Japanese Chess) player. The problem is too few worthy opponents. This may be due to the fact that playing Shogi for any length of time fosters frequent sacrifices, which totally ruins you for regular chess.

Shogi is played on a 9 x 9 square board and your pieces are pointing away from you. Your opponent’s pieces are pointing toward you. One major feature that distinguishes Shogi from Western Chess is that pieces that you capture become yours to play again anywhere unoccupied on the board. (pawns only drop onto your non-pawn lanes.) As a result, there are no draws in Shogi.

It took me about a month to recognize the Japanese characters reliably, without referring to the names and pictures. Once you study the characters, they are quite dissimilar from each other and have unique identification areas. While western chess emulates middle-ages warfare, Shogi is more a metaphor for aerial warfare a la World War 1 (and perhaps 2).

Other resources for this game include shogi.net, shogi.com, the Ricoh Shogi Club and the Computer Shogi Association which tracks the World Computer Shogi Championships.

For the last few weeks, I’ve been swamped with extra curricular activities which has constrained my writing here. I hope to resume in May.

## Sudoku Math

I am in debt to Theoni Pappas, whose Mathematics Calendar inspired this Sudoku variation. Her yearly wall calendars have the wonderful characteristic that each daily math problem shown has a solution that is that day’s number!

## Holographic Sudoku

This is a derivative of Twin Sudoku with only digits in each starting puzzle. A Book of such puzzles, called Unico Sudoku by Luigi Poderico is offered on the Lulu website. The introduction is written in the style of “Borat” (Amusing, not insulting).

## Domino Sudoku

The original starting numbers for this puzzle are from Gordon Royle’s Sudoku Patterns (Strangely Familiar Family) Number 17. It is a 17 hint puzzle, but I added the 5 to represent all the digits using Sudoku Solver By Logic to verify where to place it.

## Twin Sudoku

Without instructions, I’m showing (by example) how to do these two interrelated and yet independent Sudoku puzzles. Thanks to Henry Kwok for the idea, although his example maps two sets of digits, which may be more difficult (confusing).

## Word Search Sudoku

I’m always amused that I can’t always pronounce Sudoku properly all the time. I guess I need another year of practice. There is an upcoming book by Frank Longo called Word Search Sudoku (Mensa) to be published in April 2007.