Join the dots, close boxes and go again. Play the computer on Easy, Medium or Hard, or take turns with a friend on one screen. Three board sizes.
Dots and Boxes is played on a grid of dots, and the player with the most boxes at the end wins. On your turn you draw one line between two neighbouring dots, across or down. If your line is the fourth side of a box, you claim that box and must draw another line. One line can close two boxes at once and counts for both. If your line closes nothing, the turn passes. The game ends when all the boxes are claimed. A 3 by 3 board has 16 dots, 24 lines and 9 boxes, a 4 by 4 board has 40 lines and 16 boxes, and a 5 by 5 board has 60 lines and 25 boxes. The 3 by 3 and 5 by 5 boards have an odd number of boxes, so they cannot end in a draw; the 4 by 4 board can end 8 to 8. After the last box the game is over and there is no extra turn. Purple moves first unless you change Starts.
Tap or click a gap between two dots to draw a line. Each line has an invisible area around it so that it is 36 pixels wide to hit, even though it is drawn thin, and near a dot the tap goes to whichever line is closer. Lines are purple or teal for the player who drew them, and a claimed box shows who owns it as text (You, CPU, P1 or P2) as well as a colour. The last line drawn has a dark outline. Undo takes back your last line; against the computer it also takes back the lines the computer drew after it. With a keyboard, the arrow keys move a cursor over the lines and the boxes between them, skipping the dots, and Enter or Space draws the line under the cursor. A screen reader announces each line by the two dots it joins, whether it is drawn, and who owns each box. The score, the turn and every box claimed by the computer are announced.
Easy draws a random undrawn line, so it often hands you boxes. Medium closes a box whenever one has three sides drawn. Otherwise it draws a line that does not give a box its third side, and when every line does, it gives away the fewest boxes, counted by working out how many you could take in a row. Hard plays the same way with two additions. When it is about to take the last two boxes of a chain and doing so would leave it with no safe line and a sacrifice of 3 boxes or more, it plays the far end of the pair instead, a move called double-dealing: you take 2 boxes and then you must open the next chain. When it has to give boxes away, it prefers a line that leaves two separate boxes, so you cannot double-deal back. In the tests Hard won at least 36 of 40 seeded games against Easy on every board size, and won more games than Medium on 3 by 3 and 4 by 4. It is not a perfect player and does not search ahead beyond these rules.
A line that gives a box its third side lets your opponent claim it, so early on both players draw safe lines, those that do not make a third side. When the safe lines run out, the player to move must open something and give boxes away. A chain is a row of boxes with two sides drawn each; opening it lets the opponent take every box in it. A chain of 3, if opened at an end, gives your opponent 3 boxes. The opponent can take 1 box and then play the far end of the last two to give 2 boxes back, which forces you to open the next chain. That is the double-deal, and it is how a player keeps control of the end of the game. Counting the chains before the safe lines run out is the heart of the game. Short chains of 1 or 2 are the cheapest to give away. The game in progress, your settings and your record against the computer are saved in this browser.
By claiming more boxes than your opponent. You claim a box by drawing its fourth side. On a 4 by 4 board of 16 boxes, 9 is enough to win and 8 to 8 is a draw.
Yes. Closing a box, or two at once, means you draw another line. Your turn only passes when a line closes nothing, and there is no extra turn after the very last box.
Instead of taking the last 2 boxes of a chain, you draw the line at the far end. Your opponent takes those 2 boxes with one line and then has to move again, usually opening the next chain for you.
3 by 3 boxes has 24 lines and 9 boxes, 4 by 4 has 40 lines and 16 boxes, and 5 by 5 has 60 lines and 25 boxes. The grid of dots is one larger each way.
Tap the gap between two dots. Each line has a 36 pixel tap area around it, so you do not need to hit the thin line exactly. Undo removes your last line if you tapped the wrong one.
It never gives a third side while a safe line exists, takes boxes, and double-deals when that keeps control. In the tests it won at least 36 of 40 seeded games against Easy, but it does not look ahead further than those rules.
No. Moves are processed in your browser and not uploaded. The game in progress, your settings (mode, size, level and who starts) and your win record are saved in this browser's storage only. The page counts visits with Google Analytics, never your moves.