Spades is a four-player partnership card game built on a promise. Before each hand you bid how many tricks you expect to take, your partner does the same, and your team must take at least the combined total — no more is fine, but falling short costs you the lot. Spades are always trumps.
The tension is entirely in the bid. Underbid and you'll accumulate 'bags' that eventually cost you 100 points; overbid and you go set. Blind nil — bidding zero without looking at your hand — is the high-risk swing that can win a losing game.
Tricks taken beyond your bid. Each is worth one point immediately but accumulates — every ten bags costs you 100 points, so consistently overshooting your contract is punished.
Nil is bidding to take zero tricks, worth a large bonus if you succeed and a large penalty if you don't. Blind nil is the same bid made before looking at your cards, for double the stakes.
No — spades must be 'broken' first, meaning someone has played one when unable to follow the led suit. It stops a player leading trumps on the opening trick.