Os and Xs is a logic puzzle where you must fill the grid with X and O symbols without making three-in-a-row.

How to play

The objective of Os and Xs is the opposite of Tic Tac Toe / Noughts and Crosses - you must fill the grid with X and O symbols without placing three Xs or Os in an unbroken line (horizontally, vertically or diagonally) anywhere on the grid.

Tap an empty square in the grid to select it, then select either "X" or "O" to enter it. If you think you've made a mistake, you can tap a filled square to switch it to the opposite symbol, or tap the button for the entered symbol to clear it.

Usually, some grid squares will be already contain Xs or Os at the start of the puzzle, and you can use these to determine what your first moves should be.

Some squares on the grid are filled in solid color - you cannot place Xs or Os in these spaces, and they don't count toward the total Xs or Os in neighboring squares.

Extra help

If you're stuck on a puzzle, you can use coins to buy hints.

Hints can be used by tapping on the relevant icon in the status bar area at the top of the screen.

The cost (in coins) to use each hint is printed under its icon.

■ Help (Solve Cell)
If there are no errors on the grid, this hint will automatically make the next logical move, filling in one X or O symbol.

■ Check for errors
Use this hint to highlight all the cells with incorrect values.