Two players take turns making marks on squared paper. One draws crosses and moves first, the other draws noughts. A mark can go in any empty square. The first to get five of their own marks in a row, vertically, horizontally or diagonally, wins. Six or more marks in a row win too. If neither player has room left for five marks in a row, the game is a draw.
Watch your opponent's lines as closely as your own. If your opponent has three marks in a line with a free square at both ends, block the line straight away, or it will become a four that can no longer be stopped. If you make two dangerous lines at once, your opponent can block only one. Make a new mark close to your other marks, and it will be in several lines at once.