How to play dots and boxes
- Take turns drawing lines. Players take turns joining two neighbouring dots with a horizontal or vertical line. On a phone, press near the line you want — the closest free line lights up — and lift your finger to draw it.
- Close a box to claim it. Whoever draws the fourth side of a box wins that box (it is filled with their colour) and must draw another line straight away.
- Keep going until the grid is full. One line can sometimes close two boxes at once. The game ends when every line is drawn.
- Most boxes wins. The player with more boxes wins. Boards with an odd number of boxes (3×3 and 5×5) can never end in a draw.
On a touch screen you never have to hit a thin line exactly: the whole area around a line counts, the line you are about to draw is shown in your colour, and you can slide your finger before lifting it. With a mouse, hover to preview and click to draw.
Strategy 1: never draw the third side
A box with three sides is a free gift: the next player closes it and moves again. In the opening and middle game, only draw lines that leave every box with at most two sides. Our Normal computer follows this rule strictly — it never hands over a box while a safe line still exists.
Strategy 2: count the chains
Sooner or later the safe lines run out and the board breaks into chains (rows of boxes with two open sides, ending at the edge) and loops (chains that close on themselves). Drawing any line inside a chain lets your opponent take the whole chain.
- Give away the smallest thing first. When every line costs you boxes, open a single box or a 2-chain before you open a long chain.
- Open a 2-chain in the middle. Drawing the line between the two boxes leaves two separate boxes, so your opponent can’t use the double-cross trick on them.
- Long chains decide the game. Chains of three or more boxes are where most points are scored. The player who is forced to open the first long chain usually loses — so in the middle game, try to steer the number of long chains in your favour.
Strategy 3: the double-cross (all but two)
When your opponent opens a long chain, you don’t have to eat all of it. Take every box except the last two, then draw the line at the far end instead. Your opponent gets those two boxes with a single line — a double-cross — but then has to move again, which means opening the next chain for you. Losing 2 boxes to win the next 3, 4 or 5 is the key trade of the whole game.
Keep this “control” to the end: each time you double-cross you give away two boxes, so it only pays while the chains you will win are longer. In the very last chain, take everything.
Board sizes and the computer
Every board below is playable here. The computer columns come from 200 test games per size between our Normal computer and two weaker players, alternating who moves first: our Easy level, and a “greedy” player that always takes a free box and never draws a third side but knows nothing about chains.
| Board | Dots | Lines | Boxes | Normal vs Easy (wins) | Normal vs greedy (wins) |
|---|---|---|---|---|---|
| 3×3 | 16 | 24 | 9 | 183 / 200 | 184 / 200 |
| 4×4 | 25 | 40 | 16 | 191 / 200 | 183 / 200 |
| 5×5 | 36 | 60 | 25 | 194 / 200 | 199 / 200 |
The gap against the greedy player shows how much chain play is worth: avoiding third sides is not enough on its own. If you can beat Normal on 4×4, you are playing real dots and boxes strategy.
More two-player games
Looking for another game to play with a friend on one device? Try gomoku (five in a row) or the three-lane duel Block Battle. For solo thinking games, play peg solitaire or the box pushing puzzle. Chinese speakers can use the 点格棋 page, which shares the same saved game.