Duplicate Bridge (ACBL) Rules Explained

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Duplicate Bridge (ACBL) Rules Explained | OpenSourceSports

Full Rulebook(20 sections)

Plain-English summary drawn from the official rulebook — great for getting started. For competitive or formal play, see the Complete Rulebook. Hover any rule to see its source sentence.

Overview

Duplicate Bridge is a trick-taking card game for four players, split into two partnerships — North-South against East-West. Because the same deal is played more than once, pairs win by comparing how well they did holding identical cards rather than by the luck of the deal. Hands are preserved in a board and passed bet…

How to win

IMP scoring — Each board's total point difference converts to IMPs on a fixed scale (+ variants)
Scoring the deal — Declarer scores if the contract makes; defenders score if it fails. Vulnerability raises both.
Each contestant is compared with everyone who played the same board; Two scoring units for each score inferior to…
Scoring table — Score each deal by Law 77's table, which sets trick scores, premiums and penalties
Contract decides scoring — Declarer's side scores if it makes the contract; defenders score if it fails

Cultural norms — not in the rulebook. These are widely understood traditions and expectations among experienced Duplicate Bridge players. Not enforced by referees; enforced by the game’s community.

🚨 Cardinal Rule— Serious violation — may trigger retaliation or social exclusion

Practice "active ethics" — resolve ambiguity against yourself
— Beyond merely avoiding rule violations, experienced duplicate players are expected to interpret any doubt about a legal or ethical question (e.g., whether partner's hesitation could have suggested a call) in the way least favorable to their own side. This concept, popularized in ACBL bridge writing by editor Edgar Kaplan, goes further than what the written Laws technically require.(Most emphasized in club and tournament play among experienced partnerships.)[1]

⚠️ Strong Expectation— Most experienced players will take notice and be upset

Never criticize or berate partner during the session
— Complaining about, correcting, or scolding partner's bid or play at the table — during the round rather than afterward — is considered a serious breach of bridge etiquette. Disagreements or lessons are expected to wait until the post-mortem discussion after the round or match has ended.(Especially enforced in partnership and team events where a hostile table atmosphere is seen as poor sportsmanship.)[1]

📋 General Expectation— Generally expected; soft social enforcement among regulars

1. Introduction

Duplicate Bridge is a trick-taking partnership card game for four players. The four players at each table constitute two partnerships, North-South against East-West (Law 4).

What makes it "duplicate" is that the same deal is played more than once: hands are preserved in a board and passed between tables, so pairs are compared on how well they did with identical cards rather than on the luck of the deal.

These are the Laws of Duplicate Bridge, 2017 Revised Authorized Edition, drafted by the World Bridge Federation Laws Committee and promulgated in the Western Hemisphere by the American Contract Bridge League, effective 25 September 2017.

2. The Deck

Composition

Played with a pack of 52 cards, consisting of thirteen cards in each of four suits (Law 1A)
The suits rank downward in the order spades (♠), hearts (♥), diamonds (♦), clubs (♣) (Law 1A)
The cards of each suit rank downward: Ace, King, Queen, Jack, 10, 9, 8, 7, 6, 5, 4, 3, 2 (Law 1A)

The Cards Themselves

The Regulating Authority may require the face of each card to be symmetrical (Law 1B)
The backs of all 52 cards in a deck should be identical, so no card is identifiable from the back (Law 1C)

Duplicate Boards

Each deal is held in a board with four pockets, one per hand (Law 2)
The board designates the dealer and which side is vulnerable, so every table plays the deal under identical conditions
Boards are numbered, letting the same deal be compared across the whole field

3. Setup & Deal

Partnerships & Seating

Four players per table form two sides, North-South and East-West (Law 4)
In pair or team events contestants enter as pairs or teams and keep the same partnership throughout a session; in individual events partnerships change during the session (Law 4)
The Director assigns an initial position to each contestant at the start of a session (Law 5A)

The Shuffle

Before play starts, each pack is thoroughly shuffled (Law 6A)
There is a cut if either opponent so requests (Law 6A)

The Deal

Cards are dealt face down, one at a time, into four hands of thirteen cards, each placed face down in one of the board's pockets (Law 6B)
No two adjacent cards from the deck shall be dealt into the same hand (Law 6B)
The recommended procedure is to deal in rotation, clockwise (Law 6B)
A member of each side should be present during the shuffle and deal (Law 6C)

4. Gameplay (Auction & Play)

The Auction

The auction period begins for a side when either partner withdraws his cards from the board (Law 17A)
The player designated by the board as dealer makes the first call; thereafter each player calls in turn clockwise (Law 17B, 17C)
A bid designates a number of odd tricks — tricks in excess of six — from one to seven, plus a denomination. Pass, double and redouble are calls but not bids (Law 18A)
A bid supersedes a previous bid if it names the same number of odd tricks in a higher-ranking denomination, or a greater number of odd tricks in any denomination (Law 18B)
A bid that supersedes the last bid is sufficient; one that fails to is insufficient (Law 18C, 18D)
Doubles and redoubles increase the scoring stakes of the contract (Law 19)

End of the Auction

The auction ends when, one or more players having bid, there are three consecutive passes — the last bid becomes the contract (Law 22A)
If all four players pass, the hands are returned to the board without play, and there is no redeal (Law 22B)

The Play

After three passes, the defender on presumed declarer's left makes the opening lead face down (Law 41A)
Before it is faced, the leader's partner and the presumed declarer may ask for a review of the auction (Law 41B); dummy's hand is then spread
The player who leads to a trick may play any card in hand; each other player in turn plays a card, and the four cards constitute a trick (Law 44A, 44B)
Each player must follow suit if possible — this obligation takes precedence over all other requirements (Law 44C)
A player unable to follow suit may play any card (Law 44D)
A trick containing a trump is won by the highest trump; a trick without one by the highest card of the suit led (Law 44E, 44F)
The winner of each trick leads to the next (Law 44G)

5. Scoring & Winning

The Deal Score

Each deal is scored from the Duplicate Bridge Scoring Table (Law 77), which sets trick scores, premiums and penalties
Declarer's side scores if it makes the contract; the defenders score if it fails
Vulnerability, shown on the board, raises both the bonuses and the penalties

Matchpoint Scoring (Law 78A)

Each contestant is compared with everyone who played the same board
Two scoring units for each score inferior to yours, one for each equal score, and zero for each superior score
This is the standard method for pairs events — beating the field on a board matters more than the size of the margin

Other Methods

International Matchpoint (IMP) scoring: the total point difference on each board is converted to IMPs on a fixed scale (Law 78B) — standard for team events
Total point scoring: the raw point totals are aggregated (Law 78C)
The Conditions of Contest announce which method applies before play (Law 78D)

6. Variants & House Rules

Event Formats

Pairs events, normally matchpointed, are the most common club format
Teams events compare two tables playing the same boards in opposite directions, normally scored in IMPs
Individual events change partnerships during the session (Law 4)

Rubber Bridge

The social ancestor of the duplicate game: hands are dealt and played once, with no board and no comparison
Scoring runs across a rubber rather than per deal, so the Laws of Duplicate Bridge do not apply in full

The Director

The Director is the official representative of the Tournament Organizer and is responsible for on-site technical management (Law 81A, 81B)
The Director — not the players — has the responsibility for rectifying irregularities (Law 81C)
Call the Director as soon as an irregularity is noticed; players should never agree a remedy between themselves

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