How to play

A grid of dots is on the board. On your turn, draw one line between two neighboring dots, either across or up and down. When your line completes the fourth side of a box, the box is yours (it takes your color) and you must draw another line. When every box is taken, the player with more boxes wins. Choose a small 3 × 3 board for a quick game or a 5 × 5 board for a long one, and play against the computer or take turns with a friend on one screen. The newest line is shown in the accent color.

The computer has three levels. Easy plays random lines. Medium takes any box it can, and avoids drawing a third side of a box, which would hand you the box. Hard does that too, and when every move gives something away, it gives away as little as it can.

Tips

The game is about what happens when no safe lines are left. A box with three sides drawn is a gift to the other player, and long chains of boxes can be taken in one turn. Count the safe moves: if the number left is even or odd decides who will be forced to open the first chain, so try to change the count in your favor. When you are forced to give boxes away, open the shortest chain first. And when you take a long chain, you can sometimes leave the last two boxes by drawing the line that closes only one end (a “double-cross” sacrifice), keeping the move for yourself.