The truly great games are those with simple rules. QUADREL is a perfect example of this, adapting the famous four color theory. It may be played alone against the computer or by two people. The principle of the game is to take turns to paint in a picture frame consisting of different sized boxes. As there are a fixed number of colors, the difficulty lies in the fact that two identical colors must not be placed side by side. The loser is therefore the one who cannot respect this rule with his remaining colors, or exceeds his allotted time.