| The auction | | | | There are 35 possible bids, which include all |
| | | | combinations of 5 denominations and 7 levels |
| The auction determines the declaring side and | | | | (7-13 tricks). Thus to bid, a player is |
| the final contract, which consists of the | | | | effectively stating they expect their |
| denomination and level (number of tricks). | | | | partnership to win at least 50% of the |
| Only one of partners of the declaring side, | | | | available tricks in the pack (50% x 13 tricks |
| referred to as declarer, will play the hand, | | | | = 6.5 tricks) if allowed to play the named |
| while the other will become the dummy (i.e. | | | | contract. |
| doing nothing). In addition, if the final | | | | |
| contract is doubled (by the opponents) or | | | | A player wishing to bid must make a bid that |
| redoubled (by the contracting partnership) | | | | is higher than the preceding bid. A bid is |
| the scoring of the hand is increased, whether | | | | higher if it specifies any denomination on a |
| the contract is made or defeated. | | | | higher level, or a higher-ranked denomination |
| | | | on the same level. The denominations are |
| During the auction, each player makes a call | | | | ranked, from lowest to highest, as clubs , |
| at his turn, which must be one of the | | | | diamonds , hearts , spades , and no trump |
| following: | | | | (NT). Thus, after a bid of 3, bids of 2 or 3 |
| | | | are not allowable, but 3or 4 are. Thus, 1 is |
| Bid (stating a level and a denomination) | | | | the lowest possible bid, followed by 1 etc, |
| | | | while 7NT is the highest possible bid. It |
| Double (when the last call other than pass | | | | should be noted that the primary purpose of |
| was a bid by an opponent) | | | | the early bids is to communicate between |
| | | | partners rather than to determine the final |
| Redouble (when the last call other than pass | | | | contract. |
| was a double by an opponent) | | | | |
| | | | A double can be made only after the opponents |
| Pass (when unwilling to make one of the three | | | | have made a bid. At its simplest, this states |
| preceding calls, i.e. "abstain") | | | | that the player is so confident that the |
| | | | opponents cannot make their bid during play |
| (Note: although technically incorrect, the | | | | that the player is willing to double their |
| word "bid" is also often used informally in | | | | score if they do and the penalty if they do |
| place of "call") | | | | not. However, in modern bridge, the double is |
| | | | often used in conventional sense, to ask |
| The auction starts with the dealer and | | | | partner to bid or to pass information to |
| proceeds clockwise with each player, having | | | | partner. A "redouble" is a bid which can be |
| first evaluated their hands, making a call in | | | | made only following an opponents' "double"; |
| order. The auction ends when 3 successive | | | | it increases the points scored yet further. |
| passes occur after a bid, double or redouble | | | | In practice the redouble can also be used |
| (or if all 4 players pass in the first | | | | systemically for other purposes. Double and |
| round). | | | | redouble are in effect only until the next |
| | | | bid, i.e. any subsequent bid invalidates |
| A bid specifies how many tricks the bidder | | | | them. |
| believes that the partnership can take using | | | | |
| both their hands, and with which strain as | | | | Once the auction ends, the last bid (together |
| trump. Any bid starts with the assumption | | | | with any double or redouble that followed it) |
| that the bidder can make at least six tricks, | | | | becomes the contract, and the level of this |
| called book, plus the stated number of | | | | bid determines the number of tricks required |
| additional tricks. So the bid includes a | | | | to achieve the contract and its denomination |
| level (from one to seven, representing how | | | | determines what suit, if any, will be trumps. |
| many tricks beyond six the bidder proposes to | | | | The pair that did not win the contract is |
| make) and a denomination (also called | | | | called the defense. The pair that made the |
| strain), which is either a suit or "no | | | | last bid is divided further: the player who |
| trump". For instance, "3 hearts" asserts that | | | | first made a bid in the denomination of the |
| his partnership can take nine tricks (book | | | | final contract becomes the declarer and their |
| plus three) with hearts as the trump suit. | | | | partner becomes the dummy |