Basic Rules:

Each sudoku puzzle consists of a 9x9 grid containing numbered clues in various positions on the board. The object of this game is to fill all empty squares with a number 1 through 9 such that these numbers appear only once horizontally across, vertically across, and within each 3x3 box.

For a more detailed explanation and tips, click here.

If you want to select a puzzle by number, you can do so here.