Players: Four, in two partnerships.
Cards: A standard deck of 52. In each suit, the cards rank: A (high), K, Q, J, 10, 9, 8, 7, 6, 5, 4, 3, 2. Spades are always trump.
Deal: The entire deck is dealt out, one at a time.
Bidding: There are thirteen possible tricks to win. Starting with the dealer, each player in turn bids the number of tricks he expects to win. His bid, plus his partner's bid, make up the contract of the partnership. The total does not have to equal thirteen tricks.
A player may elect to bid Nil, indicating the intention to win no tricks. After a player bids Nil, he discards three cards from his hand, face down on the table. If his partner has bid, his partner gives him three cards from his hand and picks up the three discards; otherwise, the partner waits until after he has bid for the exchange.
Before looking at his hand, a player may bid Double Nil and exchange cards as with Nil. Note that Double Nil also doubles the bonuses or penalties. If both partners bid Nil (or Double Nil), then there is no exchange of cards.
Play: Player to the left of the dealer leads first and may lead any suit except spades. Spades cannot be led until they have been broken by a spade discard on a previous trick (unless that player has only spades left in their hand to lead). Players must follow suit if possible. A trick is won by the highest trump card played. If no trump is played, the highest card of the led suit wins the trick. Tricks are kept by the player winning them.
Scoring: The object of the partners is to fulfill their contract. If one partner has bid Nil, he and his partner's contracts are scored seperately, then the scores are combined.
Tricks count 10 points each for partners making their contract. If the contract was not made, tricks in the contract count 10 points each against due to being set. (Negative scores are possible). Tricks won in excess of the contract count 1 point each. A bid of Nil scores 100 points if made and loses 100 points if set. Double Nil is worth 200 if made, and penalized 200 if set.
If both partners bid Nil (or Double Nil), the partnership receives 200 points if both make their contracts, but there is no score if either or both are set.
A game consists of 500 points. If both sides exceed 500 points on the same hand, the side with the higher total score is the winner.
All the rest of the bidding, play, and scoring are as in the basic rules given above.
This page graciously borrowed from "Big-D's House of Cards", at http://w3.one.net/~dbarker/cards/spades.html.