Rules
UltraSet is even more advanced and challenging version of you favorite game Set!
You should be familiar with original game rules to understand what Set of 3 cards is.
But instead of looking for a single set, your task is to find 4 cards such that one pair of them makes set with the card that makes set with another pair. And this extra card may even no be present on the table!
The deck consists of 81 cards varying in four features: number (one, two, or three); symbol (diamond, squiggle, or oval); shading (solid, striped, or open); and color (red, green, or blue). Each possible combination of features (e.g., a card with three striped green ovals) appears precisely once in the deck. There is always at least one UltraSet on the table.
Examples of UltraSets:
Yellow card makes Set with first 2 cards as well as with last 2 cards and may be not even present on the table!