Klondike Solitaire

The same rules as the regular Sudoku apply. Place numbers on the board such that each row, column, and nonet has one of each. Each day, there is a new puzzle to solve. Start with the most straightforward puzzles on Mondays and see if you can make it to the hardest ones on Sundays.

If you're new to the game, here are three basic strategies you can use to improve your solving skills:

Start by looking for cells that contain only one possible number. When you find one, fill it in and then look for more.

Next, look for numbers that appear only once in a row, column, or 3x3 box. When you find one, fill it in and continue searching for more.

Use the process of elimination to help solve the puzzle. For example, if you know that a number can only be in one row, column, or 3x3 box, you can eliminate that number as a possibility from all the other cells in that row, column, or 3x3 box.

The most important thing to remember is that Sudoku is a logic puzzle. Therefore, you should avoid guessing or using trial and error for the best results in solving your puzzle. Instead, use logic to eliminate possibilities and find the correct numbers.

Advanced Sudoku Techniques

Sudoku is a number puzzle game where you need to rely on your logic and process of elimination to succeed. The goal is to fill every row, column, and square on the grid with the numbers 1 through 9. However, there's a catch; you can't repeat any number in a row, column, or square. So, while it may be tempting to guess which number goes where, you should use the process of elimination instead.

The two techniques shared below will be of interest to players who are ready to start tackling more difficult puzzles.

The X-wing

This method is used to eliminate potential candidates for a specific cell. For example, it's used when you can spot a rectangle formed by a single candidate in your notations. For this method to work, parallel pairs of sides on the rectangle must have the candidate in exactly two spots.

To use this technique: look for three cells, A, B, and C, where A and B share two possible numbers, B and C share two possible numbers, and A and C share one possible number. Then, if you find an XY-Wing, you can eliminate the shared possible numbers from all other cells in the same row, column, or 3x3 box.

Swordfish Method

Just like the x-wing method, the swordfish is used to eliminate a candidate from specific cells. Still, instead of using two rows or columns like the x-wing, the swordfish uses three rows or columns. Think of it like overlapping rectangles without the intersecting lines.

To use this method, look for three rows or columns containing three cells with the same three possible numbers. Next, you can eliminate those numbers as possibilities from all other cells in the three rows or columns.

Whatever your Sudoku skill level, from beginner to advanced, you can enjoy a brain-boosting free online sudoku game anytime.