What Is Contract Bridge and How Does It Work?

What “Contract” Means

Every card game in the bridge family is about winning tricks. What makes the modern game contract bridge is the role of the auction. Before a card is played, the two partnerships bid against each other to set a contract: a commitment to win a particular number of tricks with a particular suit as trumps, or with no trump suit at all.

The crucial rule is that you only earn the big rewards for tricks you bid as well as win. Bid 4♠ and make ten tricks, and you score the game bonus. Make those same ten tricks after stopping in 2♠, and you earn far less. The contract you commit to: not just the tricks you happen to take: is what the scoring rewards. That single idea shapes the whole game.

The Two Phases of a Hand

Contract bridge splits every deal into two clearly separated phases. Get the relationship between them clear and the game makes sense.

If you are new to either phase, our how to play bridge walkthrough covers both from the deal to the final trick, and our bridge scoring guide explains exactly why the bid contract matters so much.

How It Differs from Older Games

Contract bridge did not appear from nowhere. It is the latest in a line of trick-taking games, and seeing the lineage makes its rules feel less arbitrary.

Contract bridge, codified in the 1920s and refined ever since, made the decisive change: only tricks you contracted for count toward game and slam bonuses. Suddenly bidding accurately mattered enormously, and the rich bidding systems and conventions that define the modern game grew up to meet that need.

A Quick Example

Your side holds the values for game and an eight-card spade fit. You bid all the way to 4♠, contracting for ten tricks.

Win ten or more and the contract is made, scoring the game bonus. Win only nine and you go “down one”, conceding a penalty instead. The promise is binding: that is what “contract” bridge means in practice.

Is There More Than One Kind?

Contract bridge is a single game, but it is played in two main formats that differ only in scoring and organisation. Rubber bridge is the relaxed home version, played for a “rubber” of two games. Duplicate bridge is the competitive format used in clubs and tournaments, where every table plays the same pre-dealt hands so that skill, not luck, decides the result.

What Is Contract Bridge and How Is It Different from Other Card Games?

Contract bridge is the competitive form of bridge played at clubs, tournaments, and the world championship level. The "contract" part refers to the core mechanic: before play begins, your partnership bids to a specific number of tricks in a specific suit (or notrump). If you fulfill the contract, you score points. If you fall short, the opponents score points. The competition is not just about playing the cards well; it is about accurately predicting what you can accomplish before you know how the play will unfold.

What makes contract bridge different from most card games: the team element and the two-phase structure. Every hand has a bidding phase (the auction) followed by a card play phase. The bidding phase requires partners to communicate precisely about their hands using a structured language of bids, without saying anything that reveals their cards directly. The card play phase then requires both partnerships to apply their skill to executing or defeating the contract. Both phases require completely different skills.

Contract bridge is the basis for all serious bridge play worldwide. Whether you play rubber bridge at home, duplicate at a club, or online on BBO, you are playing contract bridge. Our how to play bridge guide covers the complete mechanics from the ground up.

What Does the Contract Actually Mean and How Is It Determined?

The contract is the final bid of the auction. It specifies a strain (clubs, diamonds, hearts, spades, or notrump) and a level (one through seven). The level indicates how many tricks above six the declaring side contracts to take. A contract of 3NT means the declaring side commits to taking 9 tricks (6 + 3) with no trump suit. A contract of 4 hearts means taking 10 tricks with hearts as trumps.

The level of the contract is won by the partnership that makes the last natural bid. After the auction ends (three consecutive passes after any bid), the highest bid stands as the contract. The partnership that made that bid is the "declaring side." The player in that partnership who first bid the strain that became the final contract is "declarer" and plays both their hand and the dummy.

Why six tricks are not counted: in the history of bridge, the first six tricks were considered automatic and not scored separately. The "book" of six tricks is assumed; the contract bidding and scoring only concern the additional tricks above six. A contract of 1-club commits to seven tricks total (book of six, plus one contracted trick). This convention is why bridge scoring can seem confusing until you understand the baseline assumption.

Contract Bridge Scoring: What Each Contract Is Worth

For the complete scoring reference with undertricks and doubled contracts, see our bridge scoring chart.

What Are the Roles of Declarer, Dummy, and Defenders?

Every bridge hand has four players in two fixed partnerships, but once the auction ends, the roles become asymmetric. The declarer plays both their own cards and the dummy's cards (the hand belonging to their partner, which is laid face-up on the table after the opening lead). The two defenders play only their own cards, but they cooperate to defeat the contract by sharing information through their leads and signals.

Declarer's role: win the auction through the bidding phase, then plan and execute the card play to make the contract. This involves managing entries between both hands, deciding when to draw trumps, and locating missing cards through inference and technique.

Dummy's role: lay all thirteen cards face-up after the opening lead, then sit quietly and not advise or comment on the play. Dummy can draw attention to possible revokes (failure to follow suit) but otherwise has no active role in the play. This can be frustrating for players who are used to playing their own cards, but dummy's silence is a fundamental rule.

Defenders' role: try to take enough tricks to defeat the contract, while sharing information with each other through a system of signals. The opening lead, the carding in each suit, and specific conventional signals (attitude, count, suit preference) are the language through which defenders communicate. See our defensive signals guide for how this communication system works.