Bridge

PLAYERS AND CARDS
There are four players in two fixed partnerships. Partners sit facing each other. It is traditional to refer to the players according to their position at the table as North, East, South and West, so North and South are partners playing against East and West. In PlaySite Bridge, players are not referred to as "North, East, South and West" Instead, the players' usernames are used, and partners still sit across from each other. The game is played clockwise.

A standard 52 card pack is used. The cards in each suit rank from highest to lowest: A K Q J 10 9 8 7 6 5 4 3 2.

DEAL
The dealer deals out all the cards one at a time so that each player has 13. Turn to deal rotates clockwise.

BIDDING
There is next an auction to decide who will be the declarer. A bid specifies a number of tricks and a trump suit (or that there will be no trumps). The side which bids highest will try to win at least that number of tricks bid, with the specified suit as trumps.

When bidding, the number which is said actually represents the number of tricks in excess of six which the partnership undertakes to win. For example a bid of "two hearts" represents a contract to win at least 8 tricks (8 = 6 + 2) with hearts as trumps.

For the purpose of bidding the possible trump suits rank as follows: no trumps (highest), spades, hearts, diamonds, clubs (lowest). A bid of a larger number of tricks always beats a bid of a smaller number, and if the number of tricks bid are equal, the higher suit beats the lower. The lowest bid allowed is "one club" (to win at least 7 tricks with clubs as trumps), and the highest is "seven no trumps" (to win all 13 tricks without trumps).

It is also possible, during the auction, to "double" a bid by the other side or to "redouble" the opponents' double. Doubling and redoubling essentially increase the score for the bid contract if won and the penalties if lost. If someone then bids higher, any previous doubles and redoubles are cancelled.

The dealer begins the auction, and play passes clockwise. At each turn a player may either:

• make a bid, which must be higher than the previous bid if any
  
• double, if the previous bid was by an opponent, and has not already been doubled
  
• redouble, if the previous bid was by one's own side and has been doubled by an opponent, but not yet redoubled
  
• pass, which indicates that the player does not wish to bid, double or redouble on that round, but a player who has passed is still allowed to bid, double or redouble at a later turn.

 North     East     South     West 
 pass      1 heart  double    3 hearts 
 3 spades  pass     4 spades  pass 
 pass      pass 

PLAY
The player to the left of the declarer leads to the first trick. Immediately after this opening lead, the dummy's cards are exposed.

Play proceeds clockwise. Each player must if possible play a card of the suit led. A player with no card of the suit led may play any card. A trick consists of four cards, and is won by the highest trump in it, or no trumps were played by the highest card of the suit led. The winner of a trick leads to the next.

Dummy takes no active part in the play of the hand. Whenever it is dummy's turn to play, the declarer plays one of the dummy's cards. Dummy is not permitted to offer any advice or comment on the play.

SCORING
As its name suggests, rubber bridge is played in rubbers. A rubber is the best of three games. A game is won by the first team to score 100 or more points for successful contracts, over several deals if necessary.

A side which has already won one game towards the current rubber is said to be vulnerable. A side which has not yet won a game is not vulnerable. A side which is vulnerable is subject to higher bonuses and penalties than one that is not.

Scores for successful contracts are entered below the line, and count towards winning a game. Other scores, such as bonuses for tricks made in excess of the contract (overtricks), or penalties for tricks short of the contract (undertricks) are entered above the line, and do not count towards winning the game.

Score for Making the Contract

For a successful contract, the score below the line for each trick (in excess of 6) bid and made is as follows:

• If trumps are Clubs or Diamonds, 20 per trick.
  
• If trumps are Hearts or Spades, 30 per trick.
  
• If there are No Trumps, 40 for the first trick, and 30 for each subsequent trick.
  
• If the contract was doubled the above scores are doubled. If it was doubled and redoubled, they are multiplied by 4.

Because of the difference in score, clubs and diamonds are called the minor suits and hearts and spades are the major suits.

SLAM BONUS
A contract to make 12 tricks is known as a small slam. A contract to make all 13 tricks is called a grand slam. For bidding and making a slam, declarer's side get an extra bonus above the line, depending on their vulnerability, as follows:

• Slam Bonus Small Slam Grand Slam
  
• Not Vulnerable 500 1000
  
• Vulnerable 750 1500

If the contract was doubled or redoubled, the bonus for overtricks does not depend on the trump suit, but does depend on whether the declarer's side was vulnerable as follows:

• Score per Overtrick Doubled Redoubled
  
• Not vulnerable 100 200
  
• Vulnerable 200 400

• Undertrick Penalty Not vulnerable Vulnerable
• Not Doubled (Each Undertrick) 50 100
• Doubled (1st Undertrick) 100 200
• Doubled (2nd & 3rd Undertricks) 200 each 300 each
• Doubled (4th+ Undertricks) 300 each 300 each

GAME AND RUBBER
A side that accumulates 100 points or more below the line has won a game. A new line is drawn under the scores. Anything the opponents had below the line does not count towards the next game they start from zero again.

Notice that, starting from zero and in the absence of doubles, to make a game in one hand you need to succeed in a contract of at least three no trumps, four spades, four hearts, five clubs or five diamonds.

The side which first wins two games wins the rubber. For this they get a bonus of 700 if they won it two games to zero, or 500 if it was two games to one. Both sides scores are then totaled and the side with the higher score wins the difference in money (if playing for money) from the side with less.

PARTNERSHIP AGREEMNT AND CONVENTIONS
As in most card games, partners are forbidden to convey information to each other directly. However, there is considerable scope for partners to exchange information within the rules of the game by their choice of bids or cards played.

The bidding mechanism is such that if a player makes a bid (or double or redouble), it is always possible for the player's partner at their next turn to override that bid with a higher bid. This makes it possible for partners to assign arbitrary meanings to bids. Bids which can be taken at face value that is they convey a genuine wish to play a contract to take the relevant number of tricks or more with the trump suit stated are called natural. Bids which carry an agreed meaning other than this are called artificial or conventional.

For example if we are partners, we might agree that a bid of one club by me shows a strong hand, but has nothing to do with wanting clubs as trumps. Provided that we both understand this, you will not leave me to play a contract of one club, but will make some other bid, natural or artificial.

The main restriction on agreements between partners about the meaning of bids is that all such agreements must be declared to the opponents. A bidding system is a comprehensive set of partnership agreements about the meanings of bids.

Players should declare their system (if any) at the start of a session. In addition, any player, at their turn to bid or at the end of the auction, may ask for and be given an explanation of the opponents' bidding agreements. The explanation should be given by the partner of the player who made the bid in question.

Similar considerations apply to the play. Partners may agree on the meaning of the choice of card played in certain circumstances. For example we may agree that when leading from a sequence of adjacent high cards such as K-Q-J we always lead the highest. Again, the opponents are entitled to know about such agreements. They may be asked about during the play.

In rubber bridge one does not often come across complicated systems and partnership agreements. One is often playing with an unfamiliar partner, or in an informal setting. Complicated agreements are more often encountered in duplicate bridge, where the players are often long-standing partners who have devoted considerable effort to their system.