What are the main rules of game Sudoku?

The main rules of Sudoku are simple:

The Goal:

* Fill a 9x9 grid with numbers 1 through 9.

The Rules:

1. Each row must contain all the numbers 1-9.

2. Each column must contain all the numbers 1-9.

3. Each 3x3 sub-grid (or "block") must contain all the numbers 1-9.

Key Points:

* No number can be repeated within a row, column, or 3x3 sub-grid.

* The puzzle starts with some numbers already filled in.

* You must use logic and deduction to determine the remaining numbers.

How to Play:

1. Start with the easiest numbers to fill in. Look for rows, columns, or sub-grids where there's only one possible location for a number.

2. Use elimination. If a number is already present in a row, column, or sub-grid, you can eliminate it as a possibility for the remaining spaces.

3. Look for patterns. Try to identify areas where multiple numbers can only be placed in a limited set of locations.

4. Don't be afraid to guess. If you're stuck, make a logical guess and see if it leads to a solution. You can always erase and try again.

Remember:

* There is only one correct solution for each Sudoku puzzle.

* Sudoku is a game of logic and patience. Enjoy the challenge!