How to play dots and boxes
The board starts as a grid of dots. Players take turns drawing one line between two dots that sit next to each other, across or down. If your line completes the fourth side of a box, you claim that box, it fills with your color, and you must draw another line straight away. The game ends when every box is claimed, and whoever owns more boxes wins.
Choose a board from 3×3 to 6×6 boxes. Play the computer at three levels or a friend on the same screen. To draw a line, tap or click near it; on a keyboard, Tab moves between lines and Enter draws the one in focus. The score boxes show the count and whose turn it is.
Strategy tips
Early game: do not hand out the third side
A box with three sides drawn is a gift to the next player. At the start, draw lines that leave every box with two sides or fewer. These are called safe moves. Eventually the safe moves run out, and someone has to give the other player boxes.
Chains and loops
By the time safe moves run out, the open boxes usually form chains (a row of boxes where taking one opens the next) and loops (chains that close on themselves). A chain of three or more boxes is called a long chain. When a player has to open one, the other player can usually take the whole thing.
The double-dealing move
This is the key idea of the game. When your opponent opens a long chain, take every box except the last two. Then, instead of taking those two, draw the line at the far end of the chain. Your opponent gets two boxes with one line, but then has to move again and open the next chain for you. You give up two boxes to keep control. With a loop, you leave four boxes instead of two.
Give away the small stuff first
When you have to open something, open the shortest chain. If it is a chain of two, draw the line between the two boxes, not at the end. That way your opponent cannot use the double-dealing trick on you.
The chain rule
Expert players count long chains well before safe moves run out. On any given board size, one player wants the number of long chains to end up odd and the other wants it even, because that parity decides who will be forced to open the first long chain. If the count is going the wrong way for you, try to merge two chains into one or split one in two while you still have safe moves.
Variants
Some players use rectangular boards, which change the parity of the chain count. Others play to a target score, or make the player who closes a box skip the bonus move, which turns it into a very different and simpler game. In a popular classroom version, kids write their initials inside the boxes they win, just as this board marks them.
For another quick duel, try Tic Tac Toe or Four in a Row.
Questions
Do I get another turn after closing a box?
Yes. Whenever your line completes a box (or two boxes at once), the box is yours and you must draw another line. Your turn ends only when you draw a line that closes nothing.
Do I have to take a box when I can?
No, taking a box is optional. Sometimes it is better to leave the last two boxes of a chain for your opponent so that they have to move next. That trick is called a double-dealing move.
How do I tap a line on a phone?
You do not need to hit the line exactly. Each line owns the whole diamond-shaped area around it, so tapping anywhere between two dots, closer to that line than to any other, draws it.
How good is the Hard computer?
Hard avoids giving away boxes, understands chains and double-dealing, and plays the last part of the game perfectly by checking every possibility. On small boards it is tough to beat.