The rules of 4x4 Sudoku are the same as the rules of regular Sudoku, with the following differences:
The puzzle is played on a 4x4 grid, instead of a 9x9 grid.
There are only 4 numbers to choose from (1, 2, 3, and 4).
Each row, column, and 2x2 block must contain each of the numbers 1, 2, 3, and 4 exactly once.
4x4 Sudoku is a simpler puzzle than regular Sudoku, but it can still be challenging. If you are a beginner to Sudoku, I recommend starting with 4x4 Sudoku puzzles. Once you have mastered 4x4 Sudoku, you can then try regular Sudoku puzzles.
Here are some tips for solving 4x4 Sudoku puzzles:
Start by looking for clues in the existing numbers. For example, if a number appears only once in a row, then it must be the missing number in that row.
Look for patterns in the numbers. For example, if a number appears in two of the three rows in a 2x2 block, then it must also appear in the third row.
Use elimination to rule out impossible numbers. For example, if a number appears in a row and a column, then it cannot also appear in the corresponding 2x2 block.
Be patient and persistent. 4x4 Sudoku puzzles can be challenging, but they are also very satisfying to solve.