Play Dots and Boxes online

It's a strategy game for two or more players that needs nothing more than a grid of dots. Players take turns joining two neighboring dots, and whoever closes the last side of a small square claims it. Most people learn it on scrap paper at school, though there's far more thinking in it than first appears.

Start with an empty grid and take turns drawing one straight line, across or down, between two dots that sit side by side. If your line closes a box, it becomes yours and you move again. Carry on until every box is taken, then count. The rules page walks through a full sample game if you'd like to see one.

There's no paid version, no locked boards and no trial period. Every size, every difficulty level and the daily puzzle are open to everyone from the first visit. All you need is a web browser.

Neither. The game opens the moment the page loads, on a phone, tablet, laptop or Chromebook. Installing it to your home screen is available as a shortcut, but it's entirely optional.

Choose vs Computer in the game settings and the computer takes the second seat. It runs on your own device, so replies come almost instantly and a patchy connection won't slow it down. You can change the difficulty between games whenever you like.

That depends on the level you pick. Easy plays loosely and will hand you boxes, which suits children and first-timers. Medium avoids obvious gifts, while Hard and Expert understand chains and work out the final stretch of the game exactly, so expect a real fight.

Switch the mode to Pass & Play and hand the device back and forth. It handles two, three or four players, each with their own color on the scoreboard. The two-player page has a board already set up for exactly that.

It does, and that bonus move is what makes the game so tense. After you close a box you must draw again, which may close another box, and so on. A single turn can sweep up a whole row if your opponent left it open.

You claim both of them. A line can sit between two squares that each already have three sides, so it finishes the pair together. You still get only one extra move afterward, not two.

Under the standard rules, taking a box is your choice. Strong players sometimes leave the last two boxes of a chain for their opponent so they can grab the next, bigger chain themselves. That trick is called a double-cross, and the strategy guide shows exactly when it pays off.

Own more boxes than anyone else when the grid is full. In practice that means avoiding the third side of a box for as long as you can, and when you're forced to give boxes away, giving the fewest. The strategy guide turns that idea into habits you can use in your next game.

In the classic game, only when the boxes can be split evenly. On a board with an odd number of boxes, such as 5×5 with 25, two players can't finish level. A 4×4 or 6×6 board has an even count, so a draw is possible, and with three or four players a shared top score can happen on any size.

Neither seat wins on its own; the board size and the way the chains form matter more. Strong players use the long chain rule: the first player wants the number of dots plus the number of long chains to come out even, and the second player wants it odd. It sounds abstract, but after a few games you'll find yourself counting chains without trying.

For a first game or a short wait, 3×3 is quick and easy to read. The board that loads by default, 4×4 on phones and 5×5 on bigger screens, is long enough for chains to matter but finished in minutes. When you want a slow, thoughtful match, go for 6×6 or the 10×10 marathon.

The French mathematician Édouard Lucas described it in 1889 under the name La Pipopipette. Lucas is better remembered for the Tower of Hanoi puzzle, which he published a few years earlier. More than a century later, the American mathematician Elwyn Berlekamp wrote the standard book on how to play it well.

The name changes with the playground. In the US you'll hear Boxes, Squares, the Dot Game or Pigs in a Pen, while many Australians and New Zealanders call it Paddocks. In Mexico it's Timbiriche, and the original French name was La Pipopipette.

It's pure skill. There are no dice, no cards and nothing hidden; both players can see the whole board at all times. Luck only seems to play a part when one person spots a chain trap and the other doesn't.

Only on small boards. In 2012, researchers Joseph Barker and Richard Korf showed that a 4×5 board ends in a tie when both sides play perfectly, and smaller boards were worked out before that. Boards of 5×5 and up are still too large to solve completely, which is why people keep finding new ideas in them.

The game was built for touch first. The board resizes to fit your screen, starting at 4×4 on phones so the dots stay easy to hit, and you can tap or drag to draw lines. Choose Install the app from the menu and it opens full screen like any other app.

Children of five or six can pick up the rules in a minute, and the game quietly practices counting, spatial thinking and patience. Older kids discover that planning ahead beats grabbing every box, a lesson that travels well beyond games. Teachers will find lesson ideas and a tournament bracket on the classroom page.