A bridge game starts once the bidding phase ends and a final contract is determined between the four players. The players use a deck of 52 cards. Each player holds 13 cards that are called the "hand".
A bridge game consists of several units called "deals". A deal consists of two phases: the "bidding phase" followed by the "play of the hand".
A bid is a bet to take the specified number of tricks above six, in the specified strain. Two conditions must be met for a bid to prevail over another one: either the bid made is a bet to take more tricks, whatever the strain is, or it is a bet to take the same number of tricks but in a stronger strain.
Here is the card order for each suit: Ace - King - Queen - Jack - 10 - 9 - 8 - 7 - 6 - 5 - 4 - 3 - 2.
The suits are assigned value with clubs the lowest and notrump the highest: clubs, diamonds, hearts, spades, notrump. The trump suit is the suit named in the final bid, other than notrump. A card of the trump suit is a winner over any card of a plain suit, when you can’t or can no longer follow suit.
In bridge, you count tricks (up to 13), not points.
The players play in turn and are obliged to play a card of the same suit as the one led. The highest card in the suit led wins the trick. If a player is out of the suit led, he can "discard" (i.e. play a card of another suit) or "ruff" (i.e. use a trump) if he wants to.
Each player plays a card in turn so the trick consists of four cards placed face up on the table. The highest card wins the trick and the winner of the trick plays first at the next one.
In rubber bridge, a side becomes "vulnerable" when it has already won one game and is thus subject to doubled penalties. When you are vulnerable, premiums and penalties are much higher. The other side is "non-vulnerable".
In contract bridge, which is the modern variant of bridge, the vulnerability of each side varies from one deal to another based on the number of deals. Vulnerability aims at diversifying opposition situations and making the game more interesting.
The different combinations of vulnerability (love all, game all, unfavourable, favourable) are rotated. When you are vulnerable, you are said to be "red". When you are not vulnerable, you are said to be "white".
These points are allocated for the tricks taken in a successful contract only. Overtricks are counted separately.
If declarer makes his contract, the number of tricks taken (over “book”, i.e. over trick 6) is counted and multiplied by the contract suit factor. Points for each trick required and taken are scored as follows: 20 points in clubs and diamonds, 30 points in hearts and spades, 40 points for trick 7 in notrump and 30 points per trick over trick 7.
These points are multiplied by two or quadrupled respectively if the contract has been doubled or redoubled.
There are 4 types of premiums in bridge: overtrick bonus, part-score bonus, game bonus and slam bonus.
You get an overtrick bonus for taking tricks in excess of those required to fulfil the contract. Overtricks are also called "extra tricks". They are not taken into account in the calculation of game and slam bonuses. They carry premium values if the contract has been doubled or redoubled.
You get a part-score bonus when the contract required is below the game level, i.e. a trick score of fewer than 100 points. A bonus of 50 points called "part-score bonus" is then automatically awarded.
A game bonus is awarded when the contract required has reached or exceeded 100 points, the contract being considered as a game here. Bonuses of 300 and 500 points respectively are given to non-vulnerable and vulnerable sides. The game bonus replaces the part-score bonus. These premiums can’t be cumulated.
Slam bonuses are divided into two categories: small slam and grand slam. A small slam is a contract requiring declarer to make six-odd, or 12 tricks in all. A grand slam is a contract requiring declarer to win all 13 tricks (7-level).
Just as in the case of the game bonus, the slam bonus can vary according to the side’s vulnerability but not whether the contract has been doubled or redoubled. This bonus is added to the game bonus.
The bonus for a small slam is 500 points when not vulnerable and 750 when vulnerable.
The bonus for a grand slam is 1000 points when not vulnerable and 1500 when vulnerable.
Here we are talking about a factor weighing heavily in point calculation. When the contract is "successful", trick points won are multiplied by two or quadrupled respectively if the contract has been doubled or redoubled.
If the contract is not fulfilled, a double or a redouble increase the number of points scored by the defence, making penalties significantly greater for declarer.
In a bridge game, if declarer is not able to take the number of tricks agreed, the contract “fails”. In that case, the penalty points are scored on the opponents’ side (the side that defeated the contract). Penalties depend on the number of missing tricks, declarer’s vulnerability but also whether the contract has been doubled or redoubled.
Some players use an easier and quicker way to calculate points. It is a scoring system that counts bridge points according to the contract and tricks.
This exhaustive table lists undertrick and overtrick values.
|Each extra undertrick
over undertrick 3
|Overtricks||20 or 30||100||200||20 or 30||200||400|
|Each extra undertrick
over undertrick 3
|Overtricks||20 or 30||200||400|