What is sudoku? It's a Japanese puzzle played on a 9x9 square grid divided into nine 3x3 boxes. What are the rules? You have to fill in the grid so that every row, every column and every 3x3 box contains the numbers 1 to 9. Is that all there is to it? Yes, like all the best puzzles it's fiendishly simple. Aren't all those numbers a bit scary? There's no need to use maths - every puzzle can be solved by logic alone. What's all the fuss about? Ah, I can see you've not played before. Some people find sudoku highly addictive. It's in all the papers you know. Which newspaper has the best sudoku? The Mail says it's the best because it was the first. The Times says it's the best because its puzzles are the most elegant. The Telegraph says it's the best because their puzzles get harder during the week. The Independent says it's the best because it has three puzzles every day. The Guardian says it's the best because all its puzzles are handwritten, not computer generated. I suspect they're all much the same. Isn't this all a bit highbrow? Not at all. The Mirror started sudoku-ing yesterday. Even the Sun launched a daily puzzle this week (called Sun Doku), right next to a giant picture of Jade Goody saying "Even I can do it... I fink".
I've not played before. Can you ease me in gently? Sure. Have a go at this dgMini-SudokuTM puzzle. What are the rules? Every row, every column and every 2x2 box must contain the numbers 1, 2, 3 and 4. OK, so the missing numbers on the top row must be 3 and 4? That's right. But there's already a 4 in the last column? Yes, so there's only one place where the 4 on the top row can go. Ah, and the missing numbers in the bottom right box must be 2 and 3? That's it. I think I've got it now! Go on, see if you can finish the puzzle off.
OK, now I'm hooked. Where can I find sudoku to play online?
The Times and Telegraph let you print out all their puzzles.
There are four months of printable archives at the Daily Sudoku.
You can play interactively online here, here and here.
Tips on how to play can be found here, here, here and here (pdf).
You can download sudoku programs here (free) and here (costs).
If you want to 'cheat', there are grid-filling websites here, here, here, here and here.