Dots and Boxes is a 2-player pencil-and-paper game in which the players take turns to fill in lines of a grid, claiming each square of which they fill in the 4th side. The aim is to claim as many squares as possible.

Dots and boxes (also known as Boxes, Squares, Paddocks, Pigs in a Pen, Square-it, Dots and Dashes, Dots, Line Game, Smart Dots, Dot Boxing, or, simply, the Dot Game) is a pencil and paper game for two (or more) players, first published in 1889 by Édouard Lucas.

Starting with an empty grid of dots, players take turns, adding a single horizontal or vertical line between two unjoined adjacent dots. A player who completes the fourth side of a 1×1 box earns one point and takes another turn. (The points are typically recorded by placing in the box an identifying mark of the player, such as an initial.) The game ends when no more lines can be placed. The winner of the game is the player with the most points.

The board may be of any size. When short on time, 2×2 boxes (created by a square of 9 dots) is good for beginners, and 5×5 is good for experts.