Quarto is a board game for two players invented by Blaise Müller.

It is played on a 4×4 board. There are 16 pieces, each of which has four attributes:

1.large or small; 
2. red or blue (or some other pair of colors, such as light or dark stained wood); 
3. square or circle; 
4. with or without a hole. 
Players take turns to choose a piece which the other player must then place on the board. A player wins by placing their piece to make four pieces in a horizontal, vertical, or diagonal row, all of which have a common attribute (all small, all circular, etc).

Quarto is distinctive in that there is only one set of common pieces, rather than a set for one player and a different set for the other. It is therefore an impartial game.