Welcome to Set with Friends! This web app allows you to play Set, the popular real-time card game designed by Marsha Falco in 1974 (Wikipedia). The game is a race to find as many sets, or three-card triplets with a certain property, as possible from among the cards in the playing area. In this online variant, this is as simple as clicking on the three cards when you find a set, and the computer will handle all the details of dealing cards and keeping score.

If you haven't played before, don't worry! We'll explain the rules below.

Set is played with a special deck of 81 = 3×3×3×3 cards. You can see some examples of Set cards above. Each card has four features that distinguish it from the others: color, shape, shading, and number. For each feature, there are three variants, as shown in the example.

A set is a combination of three cards such that for each of the four features, the variants of that feature expressed by the three cards are either all the same or all different. For example, the three cards shown above form a set, because each feature is expressed in all three variants between the cards. You can also have sets where some features are different and others are the same. The three cards below also form a set.

In the example above, the three cards are identical in shading (outlined) and color (purple), while being all different in number and shape. In general, some subset of features could be all the same among the three cards, with the rest of the features being all different. You can verify a couple more examples of sets below.

However, a triplet of cards needs to be correct in all four features to be a set. The three cards below do not form a set, due to their color. Two of the cards are green while the third is purple, so the three colors are neither all the same, nor all different.

You should practice these rules a few times until you've mastered them.

To play Set, 12 cards are dealt from the deck. When a player finds a set, they take those three cards from the playing area, and three new cards are dealt to replace the ones that were taken. The game ends when the deck is empty and no more sets are available, and your score is equal to the number of sets you've found.

In some rare occasions, there will not be any sets among the 12 cards in the playing area. In these cases, the computer will automatically deal out 3 extra cards (for a total of 15), and play will resume normally. In even rarer cases when there are no sets among these 15 cards, additional cards will be dealt out in multiples of 3.

To indicate a set in the game interface, you can select three cards either by clicking, tapping, or using the following keyboard shortcuts, if you prefer.

That's all there are to the rules of Set, so head back and start playing!