Dots and Boxes
Take turns drawing edges between the dots; complete a box to claim it and earn another move.
Complete the fourth side of a box to claim it and move again.
How it works
- Pick a grid size from 3×3 to 6×6 boxes and choose two players on one device or a match against the computer.
- Tap the gap between two neighbouring dots to draw that edge — the tap area is generous, so precise aiming is not needed on phones.
- Close the fourth side of a box to claim it in your colour and take an immediate extra turn; whoever owns the most boxes when the grid is full wins.
Frequently asked questions
- What are the rules of Dots and Boxes?
- Players alternate drawing a single horizontal or vertical edge between two adjacent dots. Whenever your edge completes the fourth side of a 1×1 box, you claim that box and must move again straight away. When every edge is drawn the player with more boxes wins, so the grid never ends in a stalemate unless the box count is exactly tied.
- Why do I get another turn after completing a box?
- That extra turn is the core classic rule and the whole reason the game has depth. It lets you run a chain of boxes in one go once a corridor opens up, and it makes the endgame about who is forced to open the next chain. This tool follows the standard rule and grants an immediate additional move for every box you close.
- How strong is the computer opponent?
- The vs-computer mode is deliberately an easy level for casual play. It uses a simple safe-edge heuristic: it grabs any box it can complete, otherwise it avoids drawing the third side of a box so it does not hand you a free one, and only sacrifices when no safe edge remains. It does not plan chains ahead, so a thoughtful human can reliably beat it.
- What is the best strategy to win at Dots and Boxes?
- Avoid drawing the third side of any box, because that lets your opponent complete it. In the endgame the key idea is the double-cross: instead of taking every box in a long chain, leave the last two for your opponent so they are forced to open the next chain for you. Controlling who opens chains matters far more than grabbing early boxes.
- Does the game run offline and keep my data private?
- Yes. Everything — the board, the scoring and the computer opponent — runs as JavaScript inside your browser with no network requests. Nothing is uploaded and no account is needed, so once the page has loaded you can keep playing even without a connection, and your games stay entirely on your device.
About this tool
Dots and Boxes is the classic pencil-and-paper game, rebuilt here as a clean, mobile-first browser version you can play free with no app and no sign-up. Start from a grid of dots and take turns drawing one edge at a time between neighbouring dots. Close the fourth side of any small square and it becomes yours, filled in your colour, and you get to move again. When the last edge is drawn the player with the most boxes wins, and a banner shows the result with an instant rematch button.
You can choose the board size from 3×3 up to 6×6 boxes to control how long a game lasts, and switch between two players sharing one device or a quick match against the computer. The vs-computer mode is an easy opponent built on a safe-edge heuristic: it always takes a box when one is available, otherwise it prefers edges that do not create a three-sided box, and it only gives a box away when it has no safe move left. That makes it a friendly practice partner rather than an expert.
The board is drawn as scalable vector graphics so it stays crisp at any size, and each undrawn edge has a wide invisible tap target, which keeps play comfortable on a phone where thin lines would be hard to hit. The score updates live as boxes are claimed, the status line always shows whose turn it is, and a new-game control lets you restart or change the grid size at any moment without reloading the page.
Beyond being a fun way to pass time on the same device, Dots and Boxes is genuinely good for teaching tactical thinking. A useful tip once you know the basics: watch for chains of boxes and learn the double-cross, where you deliberately leave the final two boxes of a chain so your opponent is forced to open the next one. Everything runs client-side in your browser, so nothing is uploaded and the game keeps working offline once loaded.