# Sudoku Royal - Online Free Sudoku Game

Here's a nicely made online free sudoku game. This Sudoku Royal game follows the standard rules of sudoku.

This game is part of the free online brain games collection.

To begin, click the Small, Medium, or Large button under the picture of the game. This opens the game in a pop-up window.

See below for a summary of the rules. For advanced techniques, visit the Sudoku Instructions page.

## Online Free Sudoku - Instructions

If you like this game, you might enjoy Daily Sudoku.

Use your powers of logical deduction to determine the numbers missing from each row and column.

Note: If you want to print out sudoku to solve with pen or pencil, see my 100 Free Printable Sudoku Puzzles page.

Sudoku is a popular number puzzle game. Brain games like sudoku train mental abilities including logic and visual perception.

Sudoku Royal. From the game developer:

Do you think you are a sudoku master? You have 4 difficulties to choose from. Try to pass even the extremely challenging levels. Train your brain with this classic version of sudoku, improve your logic and your memory.

Features: Four difficulties to choose from; Endless game; Four color themes; Hint button.

Instructions: The common rules of classic sudoku apply. Choose a square and then click on the number you want to fill.

Complete the whole 9x9 game board correctly and pass the level. Use pencil mode to take notes or you can also use the hint button.

## Old Instructions

Note: The instructions below are for the old Adobe Flash version of the game.

HOW TO PLAY. In standard sudoku (including this online game), you are presented with a 9 by 9 grid divided into 9 three-by-three boxes.

Numbers between 1 and 9 are scattered throughout the grid, with many spaces blank.

The numbers are not scattered randomly. Rather, they are part of a unique solution for the puzzle.

Your job is to figure out the missing digits, keeping the following rules in mind:

• The numbers 1 through 9 can only be used once in each row.

• The numbers 1 through 9 can only be used once in each column.

• The numbers 1 through 9 can appear only once within each 3-by-3 box.

• The sudoku puzzle has one unique solution.

To enter a number in the grid, first click the number in the number listing on the left. This highlights the number. Then click the location in the grid where you want that number to appear.

For example, suppose you've figured out that a 5 should be placed in one of the blank squares in the grid. Click the 5 in the number listing, then click the space where you want the 5 to go.

STRATEGIES. There are two basic sudoku strategies I use all the time: 1) the "sure thing", and 2) elimination.

1) The sure thing strategy is easy to perform in an online free sudoku game. To use this strategy, look for situations where it's possible for only a single number to be placed.

Consider the screen image at left. This was taken from the online free sudoku game above.

Notice how I've placed a black 5 in the 3x3 box on the right side of the puzzle. A 5 is the only possible entry for that position.

Why? Because the two red 5's I've circled, plus the existing numbers in the 3x3 box, eliminate all open positions except one.

Remember, according to the rules you can only have one number each between 1 and 9 in each row, column, and 3x3 box.

One of the circled 5's eliminates that row, while the other circled 5 eliminates that column. The box where I entered the black 5 was the only available spot in that 3x3 box.

2) The elimination strategy requires the use of pen and paper, so it's not really conducive to online free sudoku games (at least not this version).

The idea is to figure out the multiple possible entries for an empty square, then lightly pencil in those possibilities. As you work through the puzzle, you figure out which numbers are the actual solution.

If you really want to try the elimination sudoku strategy, you might need to get some blank 9x9 sudoku paper and copy down the puzzle from this online free sudoku game.

Or print out some of my free printable sudoku puzzles.

Sudoku is one of my favorite number puzzles. I've got Sudoku puzzle books that I often dip into when I feel like solving sudoku on paper rather than playing online free sudoku games. The one by Will Shortz is particularly nice.

If you haven't played much sudoku, I encourage you to give this math puzzle game a chance. It's a fun game that can help keep your brain sharp.

Published: 07/15/2014
Last Updated: 06/11/2020

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Sudoku  /  Word Search

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