Noughts and crosses on a bigger 5 by 5 board

Noughts & Crosses in Games by Zaweba has a bigger board. As well as the usual 3 by 3 grid, you can play on a 5 by 5 board, where you need four in a row to win a round. Either way it's best of five against the computer, drawn in chalk on a blackboard, and it's free and offline.

The 3 by 3 game is one most people can play to a draw without thinking. The bigger board changes that completely. With twenty-five squares and four in a row to make, there's room to set traps and room to fall into them.

Rounds, boards and series

You draw crosses and the computer draws noughts, taking turns to mark an empty square. On the 3 by 3 board, three in a row across, down or diagonally wins the round. On the 5 by 5 board you need four in a row. A game is five rounds, with you and the computer taking turns to start, and whoever wins more rounds takes the series.

To play, click an empty square to draw your cross. Noughts & Crosses is on the Board games shelf of Games by Zaweba, and you choose the board size on the title card before you start.

Why the bigger board is more interesting

On a 3 by 3 board, careful play from both sides always ends in a draw. That's fine for young children learning about lines and taking turns, but it doesn't last long for adults.

On the 5 by 5 board, there are many more lines of four, and they overlap in lots of ways. You can't simply block every threat as it appears, because by the time a line of three is showing, there may already be two ways to finish it.

Playing the 5 by 5 board well

Start near the middle. The centre squares sit on more possible lines than the edges or corners, so they give your crosses more chances to connect.

Build open lines. A line of three with empty squares at both ends is much stronger than one blocked at one end, because the computer can only block one side.

Make two threats at once. The surest way to win a round is to place a cross that sets up two different lines needing just one more. The computer can only stop one of them.

Block early. Don't wait until the computer has three in a row. When it has two in a line with space on both sides, it's often time to step in.

Use your starts. Because you take turns starting, the rounds you begin are your best chances to win. Play them boldly and be more careful in the rounds where the computer goes first.

For children and adults alike

The 3 by 3 board is a perfect first strategy game for a child, and the chalkboard look makes it feel like a classroom game. The 5 by 5 board gives older players a real contest. Both are in the same game, so the whole family can use it.

Esc pauses, F1 explains the rules again and F11 fills the screen. Games by Zaweba keeps your plays, wins and best score for each game and mode, so your records on the two board sizes stay separate.

If you want more lines to make

Drop Four on the same shelf is a four-in-a-row game in an upright frame, where discs fall to the bottom of each column. Mill is nine men's morris, all about lines of three, and Dots & Boxes is another pencil-and-paper classic against the computer.