How to play
- Players take turns drawing one line between two dots next to each other, across or down. Tap or click the gap between the dots.
- Draw the fourth side of a box and it’s yours: your initial goes inside. Then draw another line.
- One line can finish two boxes at once. You get both, and still one more line.
- When every line is drawn, the player with more boxes wins. Each board has an odd number of boxes, so there’s no tie.
The extra turn, and the house rule
In the usual rule, finishing a box means you must draw again, and you keep going for as long as each line finishes another box. That rule is what makes the game deep: a player can take a whole row of boxes in one turn, and sometimes it pays to leave a few for the other player.
Some people learned the game with a house rule: the turn always passes, even after you finish a box. To play that way, choose Two players and No extra turn in New game. Against the computer the usual rule always applies.
Board sizes
Small is 3 × 3 boxes, a game of a few minutes. Medium is 5 × 5, and Large is 7 × 7, where long chains of boxes make the end of the game a real fight. On a phone, the Large board still leaves about a finger’s width between dots.
Strategy
Safe lines
A line is safe when it doesn’t give any box its third side. Early in the game both players draw safe lines, because a box with three sides is a gift: the other player draws the fourth side and takes it. Sooner or later the safe lines run out, and someone has to give boxes away.
Chains and loops
By then the boxes have joined into chains, rows of boxes where taking one opens the next, and loops, chains that close into a ring. Whoever has to draw in a chain gives the whole chain away, so the player who must move when the safe lines run out usually opens the smallest chain first.
Leaving the last two
The key move of the game: when you’re taking a long chain, take every box but the last two, then draw the line at the far end of the chain instead of finishing it. The other player gets those two boxes, but then has to move and open the next chain for you. Giving away two boxes to keep control often wins many more. With a loop you leave four. This is called double-dealing.
Counting chains
So the real fight in the middle of the game is over who will have to open the first long chain, of three boxes or more. On these boards there’s a handy rule of thumb, the long chain rule: the player who draws first wants an even number of long chains at the end, and the second player wants an odd number. Good players steer toward their number by joining or splitting chains while safe lines are still left.
Playing the computer
Easy takes a box only some of the time and often leaves boxes for you. Medium takes every box it can, avoids drawing a box’s third side while it has any choice, and when it must give boxes away, gives the fewest it can. Hard plays for control: it counts the chains and loops, plans who will have to open the first one, and will turn down the last two boxes of a chain to keep control. It thinks for up to a second and a half.
Choose whether you draw first or second. Undo takes back your last line and everything the computer drew after it. A win after using undo is counted separately in Statistics.
A short history
The game was described in print by the French mathematician Édouard Lucas in 1889, who called it la pipopipette, and children have played it on squared paper ever since. It goes by other names too, such as Boxes, Squares and Paddocks. The mathematician Elwyn Berlekamp worked out much of its strategy and wrote a book on it, The Dots and Boxes Game. The ideas of chains, control and leaving the last two come from that line of work.
Keyboard
| Left and right arrows | Move along a row of lines |
|---|---|
| Up and down arrows | Move between the top and the left side of each box, down a column |
| Enter or Space | Draw the line under the cursor |
Playing on a phone
On a phone, tap Play to open the game on the whole screen, and the back button or ✕ to return to the page. Tap the gap between two dots to draw the line there. A tap right on a dot is ignored, so a slightly wrong tap never draws the wrong line.
Accessibility
The whole game works with a keyboard, and each line drawn is read out to screen readers with who drew it and what it completed. Boxes carry each player’s initial as well as their color, so you never need to tell the colors apart.
Your game is saved
The game in progress is kept in this browser as you play, so you can close the page and carry on later. Your statistics against the computer are kept here too. Nothing is sent anywhere.
Questions
Who goes first in Dots and Boxes?
Either player can. Against the computer you choose in New game. With two players, the first name in New game draws first.
Do you have to draw again after finishing a box?
Yes, in the usual rule. Finishing a box gives you another line, and you have to draw it, even if it gives a box away.
Can Dots and Boxes end in a tie?
Not here. Every board has an odd number of boxes, 9, 25 or 49, so one player always has more.
Why did the computer leave me two boxes?
That’s double-dealing. By leaving you the last two boxes of a chain, the computer makes you move next, and your next line opens another chain for it. It’s usually a sign it has worked out that it’s winning.
Does the computer play the same way every time?
No. When several lines are equally good it picks one at random, so games differ.
Can two people play on one phone?
Yes. Choose Two players in New game, type your names, and pass the phone between turns. Games between two players don’t count in your statistics.
More to play
- Sudoku: Fill the grid so every row, column and box holds 1 to 9.
- Queens Puzzle: Place one queen in every row, column and colored region.
- Minesweeper: Open every square without a mine. The numbers tell you where they are.
- 2048: Slide the tiles and join equal numbers. Can you make 2048?
- Double Drop: Drop numbered blocks into five columns. Equal blocks join and set off chains.
- Memory Match: Turn over two tiles at a time and find every matching pair.
- Snake: Steer the snake to the food and grow longer. Don’t hit the wall or your tail.
- Checkers: Jump and capture across the board, and crown your kings. Also called draughts.
- All games
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