The object of the game is to clear the tableau by removing cards in sets of three. Once a set is made it is removed from the tableau and three news cards are dealt in its place. When there are no valid sets remaining on the tableau the game is over.

A card has four properties: number, shape, color and fill. Each one of these properties may have one of three different values. For example, a card will possess one, two or three shapes which will be either rectangles, ovals or diamonds. These shapes will be colored red, green or blue and will be either solid, shaded or empty.

A valid set consists of cards where each property either matches across all three cards or is different across all three cards. Taking number as an example, in a valid set each card must have either the same number as the other two cards in the set or a different number from both other cards. Similarly, for color, in a valid set all three cards must have the same color or all three colors must be represented.

To form a set, select three cards by touching them. If the set is valid the cards will disappear and three new cards will be dealt in their place. If not, the tableau will shake but the cards will remain selected. To deselect a card touch it again.