The rules for a Sudoku puzzle are simple.
A number of squares is given and the rest has to be filled in.
When filled in properly (solved), each row, column and 3x3 region contains all of the digits 1 to 9.
This page does not give you any puzzles to solve. It will (try to) solve these puzzles for you.
Just fill in the given numbers/fields and click the Solve button below the square.
A new page will give you the solution and the rules used.
For more information regarding the solutions provided by these pages, see below the square.
I started this page when a few acquaintances had problems solving the puzzles published in a local paper.
I derived some rules to solve the puzzle (1a, 1b, 2a, 2b, 3a, 3b, ...). Also known as singlets, pairs, triplets, etc. Solving some puzzles myself, I came up with another rule, which I called the unnumbered one. Better known as 'locked candidates'.
See http://homepages.cwi.nl/~aeb/games/sudoku/ for a complete treatise on the subject. Check out the chapter 'Matching'.
For a lot of links referring to Sudokus check the topic Collection of solving techniques in the forum 'Advanced solving techniques' on www.sudoku.com.
Currently implemented are 1a, 1b, 2a, 2b and the unnumbered one. Surprisingly these seem to solve all the puzzles in the newspapers.
Not completely surprising a few puzzles were reported which are not solved by this page.
If this page does not solve your puzzle, please let me know which puzzle it is and where you got it from.
If you have any remarks or questions, you can always contact me.