Dots & Boxes

Take turns joining two neighbouring dots with a line. Close the fourth side of a box and it is yours, and you go again. When every line is drawn, whoever owns the most boxes wins.

The board is a square of dots. On your turn you join two dots that are next to each other, up and down or side to side. That is the whole move.

When your line closes the fourth side of a small square, that box is yours - and you go again. Keep closing boxes and you keep the turn, which is how one good move turns into six.

One line can close two boxes at once. You score both, and you still get exactly one more turn - not two.

Play until every line on the board is drawn. Whoever owns more boxes wins; the same number each is a draw.

The trick worth knowing: a line that gives a box its third side is an invitation. Your opponent takes that box, then the next one, then the one after that. Late in a game the player who runs out of safe lines first is usually the one who loses, so save the safe moves.

Before you start, pick the size of the board and who you are playing. Two players share one phone and take turns; the computer plays at Easy, Medium or Hard - Hard counts how many boxes each line would hand over and picks the cheapest one.

Touch: tap anything on the board to use it. Every button and key is at least 44px tall, so it works with a thumb. The squares of a board are as big as the screen allows - on a small phone some of them are smaller than that, which is why the keys and the number pad, not the squares, are what you type with.

Keyboard: Tab moves between the controls and Enter or Space activates the one you are on. That covers the buttons the game screen always has - Pause, Restart and this page's link - as well as anything the board adds.

Pause stops the clock and freezes the board; Restart gives you a fresh one. Both players use the same device, taking turns - whose turn it is is always named on screen.

Your score is the points you have when the game ends. Higher is better.

Play as often as you like. Every game is saved on this device, and your best turns up on the scoreboard.