The deck. Forty cards in four suits — denari (coins ◆), coppe (cups ♥), spade (swords ♠), bastoni (clubs ♣) — ranked 1 through 10. A card's value is its number.
A turn. Play one card from your hand. If it captures, your card and what it caught go to your pile. If it captures nothing, it stays on the table for the taking.
Capture. Your card takes a single table card of equal value, or any set of table cards whose values sum to it. The forced single: if a lone table card equals your card, you must take that single — you can't reach past it for a prettier sum.
Scopa. Clear the whole table with a capture and you sweep — a point, marked then and there. (Not on the hand's final card.) Cards left on the table at the end go to whoever captured last.
The four points + sweeps. Most cards (≥21). Most coins. The settebello — the 7 of coins. And the primiera, scored on a scale that doesn't match rank: a 7 is worth 21, a 6 worth 18, an ace 16, then 5,4,3,2 descending, and every face card just 10. Your best card in each suit, summed — so a low 7 outweighs a king. Ties award nothing. Game runs to 11.
I learned this game one afternoon and got bitten by the forced single and a misfiled 7. This is the thing I wished existed afterward.