The rules of bridge

This page describes contract bridge as defined by the international laws of the World Bridge Federation (WBF). The rules should not be confused with bidding conventions, which are agreements between partners: they are covered separately, on the Bidding page.

The deck and the players

The game is played with a 52-card deck, without jokers. The four suits are spades ♠, hearts ♥, diamonds ♦ and clubs ♣. In each suit, the cards run from the ace (highest) down to the two: ace, king, queen, jack, 10, 9... down to 2.

The four players are named after the compass points. North and South are partners, sitting opposite each other; so are East and West. Each player is dealt the 13 cards of a hand; the four hands together make up a deal.

Tricks

A trick consists of four cards, one from each player, played clockwise. The first player chooses the suit. The others must follow suit if they can; otherwise, they may play any card. The trick goes to the highest card of the suit led, unless someone has played a trump: the highest trump then wins. The winner of the trick leads to the next one. A deal has 13 tricks.

The bidding

Before play, the players call in turn, starting with the dealer. Each player may:

• bid a level and a denomination, for example "1♥" or "2NT";
• pass;
• double the opponents' last bid, or redouble the opponents' double with their own bid.

Each bid must be higher than the previous one: a higher level, or the same level in a higher denomination. The ascending order is clubs, diamonds, hearts, spades, then no-trump. After 1♥, you can bid 1♠ or 1NT, but not 1♦. The bidding ends after three consecutive passes; if all four players pass right away, the deal is thrown in (a "passed-out" deal).

The contract, trump and no-trump

The last bid becomes the contract. The level indicates the number of tricks to win beyond six: a contract of 4♠ requires 10 tricks out of 13, a contract of 3NT requires 9. Level 1 therefore requires 7 tricks, and level 7 requires all of them.

The denomination names the trump suit: in 4♠, spades beat all the other suits. At no-trump (NT), there is no trump suit: only the highest card of the suit led wins the trick.

Declarer and dummy

The declarer is the player on the winning side who first named the denomination of the contract. The player to their left leads (plays the first card). The declarer's partner then lays their cards face up on the table: this is the dummy, whose cards the declarer plays. The other two players are the defenders.

On this deal, North opens 1NT and South raises to 3NT: North was the first to name no-trump, so North becomes declarer. East, on North's left, leads; South is the dummy. With all cards visible, this contract makes 10 tricks, one more than the 9 required.

Vulnerability

A vulnerable side earns more if it makes a game or a slam, but pays more for its undertricks. In duplicate, vulnerability and dealer are set by the board number, following a 16-board cycle. The first four:

In rubber bridge, a side becomes vulnerable as soon as it has won a game. In Chicago, a four-deal cycle applies.

Scoring

In duplicate, each trick bid beyond six is worth 20 points in a minor suit (♣ ♦), 30 in a major suit (♥ ♠) and at no-trump (40 for the first one). If these trick points reach 100, the contract is a game: 3NT, 4♥, 4♠, 5♣ or 5♦. A bonus is added: 50 for a part-score, 300 for a non-vulnerable game, 500 if vulnerable. A small slam (level 6) adds 500 or 750, a grand slam (level 7) adds 1,000 or 1,500.

An undoubled undertrick costs 50 points per trick short (100 if vulnerable). Doubled, it costs 100, then 200, 200 and 300 for each further trick, or 200 then 300 per vulnerable trick; a redouble doubles these amounts. In tournaments, scores are then compared across the tables that played the same deal, in matchpoints or IMPs.