A two-player card duel. Race Nova to empty your pile.
You sit across the table from Nova, and you are both racing to do the same thing: empty your pile before the other one does. It plays in a couple of minutes, and it is harder than it looks.
Four foundation stacks sit between you. They climb one suit at a time, 1 through 10, and only a 1 can start an empty one — so the 1s in your hand are worth more than they look.
Nova's discard pile is the other way out. You can play onto it whenever your card is exactly one higher or one lower, and there the suit does not matter at all. A 6 will take a 5 or a 7.
If a card can go to a foundation, it must go to a foundation.
Play it to Nova's discard instead — or draw a new card while a playable one is sitting there in the open — and that is a Tivitti. You forfeit the turn, and Nova gets a free run at the table.
It is the rule that makes the game a game. Once you are watching for it, you start seeing the board the way Nova does.