How to Play Dots and Boxes
Dots and Boxes is a pencil-and-paper game for two players. You start with a grid of dots. Players take turns joining two neighbouring dots with a line. Whoever draws the fourth side of a box claims it and moves again. When every line has been drawn, the player with more boxes wins. The French mathematician Édouard Lucas first described the game in 1889, and it has been a classroom favourite ever since.
Setup
- Draw a rectangle of dots. kawu offers 3×3, 5×5 (the default) and 7×7 boxes, which need 4×4, 6×6 and 8×8 dots.
- No lines are drawn at the start. The daily board is different: it starts with a few lines already drawn, the same for everyone that day.
- Decide who moves first. On kawu you can choose in the settings.
Taking a turn
On your turn, draw one line. It joins two dots that are next to each other, either across or up and down. Diagonal lines are not allowed, and you can't draw over a line that is already there.
On kawu, tap or click between two dots. The line under your pointer is previewed before you draw it. With a keyboard, the arrow keys move between lines and Enter or Space draws one.
Completing a box
If your line is the fourth side of a box, the box is yours. Your colour and letter go in it (P for you, C for the computer). Then you must draw another line. This can chain: if each new line completes another box, you keep going.
A single line can complete two boxes at once when it is the last side of both. You take both, but you still get only one extra line.
Your turn ends as soon as you draw a line that doesn't complete a box.
You never have to take a box. Sometimes it's better to leave one or two for your opponent; the strategy guide explains when.
End of the game
The game ends when every line has been drawn. By then every box has an owner. The player with more boxes wins. kawu's boards all have an odd number of boxes, so there is always a winner. On a board with an even number of boxes the game can end in a tie.
Board sizes
| Board | Dots | Lines | Boxes | Typical game |
|---|---|---|---|---|
| 3×3 | 16 | 24 | 9 | A minute or two; good for learning |
| 5×5 | 36 | 60 | 25 | The classic size, about five minutes |
| 7×7 | 64 | 112 | 49 | Long chains and a real endgame |
House rules and variants
- Who moves first. There is no fixed rule; take turns between games.
- Taking boxes is optional. That is the standard rule, and kawu uses it. Some casual players believe you must take every box you can. That makes the game much simpler, because the double-cross disappears.
- Pre-drawn border. Some people start with the outer edge of the board already drawn. This changes the opening but not the rules.
- Other grid shapes. Players sometimes use triangles or hexagons. kawu sticks to squares.
Playing on kawu
- Computer levels. Easy only avoids giving away boxes. Normal knows to give away the shortest chain and uses the double-cross. Hard plays the full chain-control strategy and calculates the endgame exactly.
- Two players. Tick Two players on this device in the settings to play a friend on the same screen.
- Undo and hints. Undo takes back your last line, and Hint shows the line the computer would draw.
- Daily board. Everyone gets the same 5×5 board with a few lines already drawn, against the normal computer. Try to take as many boxes as you can.
Once you know the rules, read the Dots and Boxes strategy guide. It explains chains, loops and the double-cross, which is where the game really starts.
Frequently asked questions
Do you get another turn after completing a box?
Yes. Whenever your line completes a box you take it and must draw another line. If that line completes a box too, you go again, and so on. Your turn ends with the first line that completes nothing.
What happens if one line completes two boxes?
You take both boxes, but you still get only one extra line. The bonus is per line drawn, not per box.
Do you have to take a box when you can?
No. Taking a box is never compulsory. Strong players sometimes leave the last two boxes of a chain for their opponent on purpose. This is the double-cross, explained in the strategy guide.
Can Dots and Boxes end in a tie?
Only on boards with an even number of boxes, such as 4×4 or 2×3. kawu's boards are 3×3, 5×5 and 7×7 (9, 25 and 49 boxes), so every game has a winner.
Who goes first?
Players usually agree or toss a coin. On kawu you move first by default; you can let the computer start in the game settings. The daily board is always played with you first.
Last updated 2026-10-17