There are certain mathematical calculations which enter into the bidding, the play and the defense procedure. These calculations are important in their application and should be used under the correct circumstances. They help in assisting and deciding which card to play, which defense and which offense strategy to use, and they keep the Line of Communication open, especially between the opponents. They should be used with accuracy due to their effectiveness. They can make the difference between a made contract or a set contract.

Note: one of the many definitions of the term is that a rule is an authoritative, prescribed direction for conduct, especially one of the regulations governing procedure in a legislative body or a regulation observed by the players in a game, sport, or contest, and also directions that define the way a game or sport is to be conducted.

There are several rules, and each one has its place at the bridge table. The attempt has been made to list those rules, which are perhaps universal. Also, the attempt has been made to list those rules, which are the result of practical experience and have been proven to be effective. The latter have been described in so-called one-liners, and we hope that the reader devotes his or her attention also to these general guidelines.

Note: The list on this web page is not alphabetical, but rather numerical.

Hamman's Rule
"When 3 No Trump is one of the alternatives, choose it." A quote by Mr. Robert (Bobby) Hamman. The idea behind this rule is that fact that a contract of 3 No Trump requires fewer tricks for a game contract and even if there is a winning defence, then the defenders may indeed may lead a most favorable suit, which allows the declarer to fulfill the contract.

Golden Rule
This particular bidding rule was postulated by Mr. Alan Truscott. This golden rule dominates as a fundamental principle and feature of most bidding systems, which state that any suit bid and rebid must be a 6-card suit.

Goldwater Rule
The satirical recommendation by Tournament Director Mr. Harry A. Goldwater that an opening lead out of turn should generally be accepted, since the player, who does not know whose turn it is to lead, usually does not know the correct lead either.

Note: Mr. Harry A. Goldwater was born in the year 1901 and is of Yonkers, New York, United States. As of the year 1957 he was an accredited national tournament director of the American Contract Bridge League. He became known as a legend owing to his immense knowledge of the Laws governing the rules of the game, for being patient, easy-going, outward-going, personable, and always friendly to all players of all levels.

Rule of Coincidence
This guideline or rule, generally for Tournament Directors, applies when one player has made a call which compensates for the mis-description of partner's hand. For example, a player overbids his hand by 3 high card points and partner underbids to compensate. In such a case it is apparent that an undisclosed partnership agreement exists.

In the case of computer online bridge the designation is abbreviated to: RoC. Since the Rule of Coincidence is not a part of the Laws of Duplicate Contract Bridge, but rather an added and subsequent feature employed to address the situation of restoring equity among the players, this feature has been debated as to its validity and application. (Note: see Glossary for additional information.)

Rule of Three Queens
In The Bridge World magazine issue of March, 2003, Mr. Danny Kleinman expressed the Rule of Three Kings, which states that the bridge player be alert to the possibility of playing in No Trump when a suit contract seems obvious and to let the possession of Queens sway the bridge player in close cases. Or, when the bridge player has 3 (or 4) Queens, make an extra effort to play in No Trump.

Trappist Rule
This suggestion is strongly endorsed by Kitty Munson Cooper, United States, in the year 1990 in a published article for the BOLS TIPS, which can also be found online at various sources. The rule is rather fundamental in the conduct of a bridge player, and as Kitty Munson Cooper formulated in 1990: Taking the Trappist Vow of silence eliminates many problems between two players at the table during the bidding sequence and the play technique either as defender or as declarer. By saving the analyses and also the possible, ensuing arguments for a later time will improve the concentration of the player and, as a result, reduce the rate of error or erratic play. This principle should be followed at all times.

Note: The designation of Trappist is defined as the Order of Cistercians of the Strict Observance (O.C.S.O.: Ordo Cisterciensis Strictioris Observantiae) is a Roman Catholic religious order of cloistered contemplative monastics who follow the Rule of St. Benedict. A branch of the Order of Cistercians, they have communities of both monks and nuns, commonly referred to as Trappists and Trappistines, respectively.

Note: Trappist monks generally speak only when necessary. Therefore, idle talk is strongly discouraged. According to St. Benedict, speech disturbs a disciple's quietude and receptivity, and may tempt one to exercise one's own will instead of the will of God. Speech that leads to unkind amusement or laughter is seen as evil and is banned.

Rule Of X-Plus One
This is a mathematical formula, devised by Mr. Ely Culbertson, to help in planning the play when the contract is No Trump. By an attempt to establish the long cards in a suit, estimate the number of losing tricks in the suit before it can be established and call it X. Add 1 to this number. The result is the number of stoppers in the opponent’s long suit needed to be able to turn the long cards into winning tricks.

Rule of Two
This is a guideline, which states that if the declarer is missing two touching honors, then it is preferable to finesse first for the lower honor. The possibility that there could be individual and special circumstances where this action would be incorrect is present. However, the mathematical percentages offer a higher success rate, as in the following examples:

Dummy: AQ10
Declarer: 542

The Rule of Two states that the declarer should first The Rule of Two states that thee the Ten for the maximum number of possible tricks.

Dummy: KJ1084
Declarer: 6432

The Rule of Two states that the declarer should first finesse the Jack.

Rule of Two and Three - Rule of 2 and 3
The concept of the rule of two and three is basically a general guideline employed by the bridge player in determining whether to make a preemptive bid, whether to overcall or overbid, whether to make that sacrifice, or to simply pass. The rule of two and three is a method of determining the better score. As proposed by Mr. Ely Culbertson for preemptive openings and overcalls, the partnership should be within two tricks of their contract, if vulnerable and deciding to sacrifice for the sake of a better score. If the partnership, however, loses three tricks while not vulnerable, then the partnership can also achieve a better score.

Rule of Four
This is an overall general acceptance of the belief that it is always better to play in a 4-4 fit rather than in a 5-3 fit, since the percentages of the possibility of being able to sluff several losers are higher. This also affects the bidding auction. Examples have been given to show that, when holding: S: AQ5, H: KJ74, D: A863, C: 62, and the partner opens with: 1 Spade, it is more prudent if the first response is: 2 Diamonds, instead of immediately raising partner in Spades. The possibility that the partner rebids: 2 Hearts, is present and would offer the partnership a preferable 4-4 split in Hearts with a known 5-3 split in Spades.

Rule of Five or The Five Level Belongs to the Opponents
The origin of this particular guideline or rule is attributed to Mr. Grant Baze. This is a general guideline adopted by many bridge players and which states that if the opponents, in a competitive auction, have reached the level of five, then the conclusion is that it is better to defend. This conclusion is based on studies, experience and mathematical percentages of the average results. The same principle can also be applied to low-level contracts at the three level. It is a rule or guideline, which is based on the law of averages.

Rule of Five and Five
During the 1980s the ACBL issued a policy governing the rules and regulations of ACBL sanctioned bridge events, generally sectional and regional tournaments, that Weak Two Bids should not contain fewer than 5 high card points and that the suit should be a holding of at least five cards or more, but no fewer than 5 cards. This has become known as the Rule of Five and Five.

Note: Also known as the ACBL Rule of 5 and 5, which was put into effect owing to the fact that Mr. Marty Bergen continually opened a Weak Two bid based on 4 and 4, a minimum of 4 high card points and a minimum of a 4-card suit. Once Mr. Marty Bergen complied with the decision of ACBL, then the restriction was withdrawn by ACBL.

Rule of 6-4-2 and Rule of 4-2-1
In his publication entitled More Bridge Brilliance and Blunders, 1975, Mr. Richard A. Miller published the following describing a method of counting ruffing tricks in the responding Hand. The following is an excerpt from that published work:

When partner opens the bidding and a trump suit has been established, the responder must evaluate his hand by combining his high card strength with his ruffing trick strength. Such strength may be expressed with the formula of Rule of 6-4-2 and Rule 4-2-1:

Short Suit 4 Trumps 3 Trumps
Void 6 points 4 points
Singleton 4 points 2 points
Doubleton 2 points 1 point

An additional point may be added for each trump over four. With two short suits, count only one, the shorter. The additional short suit is already counted in assigning one point to any length in the trump suit over four.

Ruffing or trumping values as shown in this table are counted by the responder only on the assumption that partner will become the declarer and his bid suit will be trump. Should subsequent bidding place the contract in No Trump, count assigned to ruffing tricks must be deleted and replaced with high card count and long suit count.

On the other hand, if the responder should originate a suit and become the declarer, the long cards are counted and the opener, who now is dummy, will count his ruffing tricks.

Notice that this count is the only one now in use that differentiates specifically between holding four trumps as against three trumps. That one trump, the fourth, can mean maximum efficiency in ruffing power and optimum contracts. The loss of the fourth trump can and does reduce the ruffing potential of the dummy hand and therefore the difference must be acknowledged in the basic formula.

The Rosetta stone from which these evaluation tables were derived is Charles H. Goren's The Standard Book of Bidding, published in 1944.

Rule of Seven - Rule of 7
The rule of seven was created and implemented separately by two bridge personalities. One is Mr. Robert Berthe of France, who is a published author of bridge book(s). Mr. Gerald Fox of Napa, California, United States, bridge expert, teacher, and author, also independently devised the rule of seven.

Rule of Eight - Rule of 8
The rule of eight was proposed by Mr. Mel Colchamiro and first published in The Bridge Bulletin of ACBL in October 2000, Page 85. When deciding to employ the rule of eight, the player first subtracts the number of Losing Tricks from the total number of cards contained in the two longest suits. The concept is based upon the result.

Rule of Eight or Rule of 8
This guideline or rule pertains to the suit quality when deciding to preempt. The player adds the number of cards in the longest suit and adds the number of honors in that suit. When the total equals eight, then the player should preempt on the two level. When the total equals nine, then the player should preempt on the three level.

In evaluating the holding and deciding to make the preemptive bid or not, the player should evaluate the holding according to the following guidelines. When assessing suit quality, the Jack and the Ten are counted only if the suit also contains a higher honor such as an Ace, King, or Queen. The suit has to contain at least 6 cards. For example: J108643 has a suit quality of 6 since the suit does not contain any honor higher than the Jack. The holding of KJ8653 has a suit quality of 8, or 6 cards in length plus 2 honors. The Suit Quality Test is useful when the quality of a suit is relevant to your bidding decision.

The suit quality should equal the number of tricks for which the player is bidding. Thus a weak two opening should have a suit quality of 8 or a 6-card suit plus at least 2 honors; a three level preempt should have a suit quality of 9 or a 7-card suit plus at least 2 honors or a 6-card suit plus at least 3 honors, and so on.

Rule Of N-Minus-One
This rule for squeezes was first published by Mr. Ely Culbertson in the book Red Book On Play. His definition of this rule states that the player should count the number of busy cards in the plain suits held by one opponent. This number is represented by the symbol N. Therefore, N minus 1 equals the number of uninterrupted winners the declarer needs for a squeeze.

Rule of Nine - Rule of 9
The origin of this rule is unknown, but it has been attributed to Mr. Ray Depue. The source of this information is no longer available online. Any additional information would be greatly appreciated. In certain auctions the opening bidder must determine whether to continue to compete after a low-level overcall has been made, which is then followed by two passes. The rule of nine allows the opening bidder to judge better the possibility of continuing to compete or whether to defend.

Rule of 9s and 10s
The origin of this rule has been lost in bridge history and can not longer be attributed to any one bridge player or bridge author. It simple developed as a method and was included in partnership agreements as a form of defense. It is sometimes referred to as Coded 9s and 10s.

Rule of Ten - Rule of 10
This mathematical concept originated back in the days of the game of Whist. This rule allows the partner, who leads the first card, to determine the distribution of that suit among all four players. The name of the originator is lost to history.

Rule of Ten - Rule of 10
This particular guideline, called also the rule of ten, applies to a competitive auction when one player contemplates to employ a penalty double even though the opponents have not bid a game contract.

Rule of Eleven - Rule of 11
The rule of eleven is a mathematical calculation, equation, formula. Its application becomes active, only when the player is absolutely certain that the lead is the fourth down from the suit lead. Once the bridge player, either defender or declarer, has ascertained this partnership agreement, then the bridge player begins counting. The principle behind the rule of eleven is the same whether the contract is a suit contract or a No Trump contract.

Rule of 11, 12, 13
This is a method of evaluating the value of 13 cards and whether to open the auction, compete in the auction, or to pass. This method was promulgated and/or devised by Mr. Richard A. Miller, the author of the books Point Count Bidding, published 1946, and which contained an evaluation method based on the Work Count for suit bidding: Aces = 4; Kings = 3, Queens = 2, Jacks = 1. It counted long suits, playing tricks, in the opening hand, assigning one point for the fifth and one point for the sixth card of a long suit, usually the opened one. To this it added the high card count, honor tricks, and suggested opening the bidding with:

11 points and six-card suit.
12 points and five-card suit.
13 points and four-card suit.

As the shape of the hand flattens out, the high card requirements go up. In effect the opening bid is made with 13 points each time with one point each being added for the fifth and sixth card of the long suit. Shape, or distribution plays an important part in suit valuation and the published article suggested that an opening bid may be made with 10 points in high cards when holding two 5-card suits provided that at least 8 of the points are located within the long suits. In evaluating the potential of the combined hands, partner will always assume that opener holds a minimum of 13 points, of which no more than three can be credited to the distributional factor.

Rule of Twelve - Rule of 12
The re-popularization of this lead from the era of Whist is attributed to Mr. Sven Welith and Mr. Seth Wenneberg, both from Sweden. Similar to the rule of eleven, which may determine the play of a card by partner, who knows that the lead card is the fourth highest card down as per partnership agreement, the rule of twelve is a mathematical calculation from the days of playing Whist when the lead card is the third highest card.

Rule of Thirteen or Rule of 13
This guideline or rule is applied when considering opening with a strong, artificial 2 Clubs bid, when the high card points of the holding do not exceed 22 high card points and the question remains whether to open with one of a suit or with a strong, artificial 2 Clubs bid. The concept is based upon adding the number of total defensive tricks and multiply by two. Defensive tricks are determined according to the following:

Ace: 1
Ace/King: 2
King/Queen: 1
King/x: 1/2
Queen/Jack/x: 1/2

Once this tally has been accomplished, then the player should add all length cards of more than three in a suit to the result. If this final result is then 13 or more, then the player should open with a strong, artificial 2 Clubs bid.

Rule of Fourteen - Rule of 14
In the words of the author the Rule of 14 does not assist the declarer to determine whether the conditions necessary for the squeeze to succeed exist, nor does the Rule of 14 indicate the proper technique for the execution of the squeeze. The Rule of 14 simply indicates that a squeeze is possible. (Note: there are various explanations of the Rule of 14, as well as other rules, on the Internet, and the interested bridge student should also review these explanations for a comprehensive rendering of the concept.)

Rule of Fourteen - Rule of 14
This particular Rule of 14 is presented by Mr. Harold Schogger. It states that if the responder wants to reply at the two level in a lower ranking suit, i.e. 2 Clubs or 2 Diamonds over the opening 1 Spade bid of partner with very minimum hands, then the responder should use the Rule of 14 to justify responding on as few as 8 high card points. (Note: the original online presentation has been deleted.)

If the responder is not certain, then the responder should apply the Rule of 14 as a guideline to determine the action taken. The guideline suggests that the responder add the number of high card points to the longest suit held, and if the total amounts to 14 or more, then the responder should bid on the two level. If not, then the responder should respond 1 No Trump with no support for partner. Several examples to clarify the difference:

Response: 2 Response: 1 NT

Note: Mr. Harold Schogger has also presented on YouTube a video explaining this particular Rule of 14. This video can be found at YouTube. This film is also presented on this site with a link directly to YouTube for the convenience of the visitor. This is an embedded film, which lasts 4:54 minutes.


14 Spade Guide
Sometimes referred to colloquially, and depending on the geographical region, as the 14 Spade Guide or Rule of 14, but see other Rules of 14 listed on the web page, which present different concepts. The 14 Spade Guide operates and is executed only in one specific auction / bidding situation.

Rule of Fifteen - Rule of 15
The Rule of 15 allows the bridge player, following three consecutive passes, in the fourth seat to better determine whether or not to open the auction by bidding.

Rule of Fifteen
This is a general rule applied by the Australian Bridge Federation to govern the opening of Weak Two bids. The guideline is that the Rule of 15 allegedly requires that the total of high card points and the number of cards in the two longest suits must equal 15 or more. This guideline is more fully explained by the ABF in their following clarifying statement:

The important issue is that ABF System Regulations apply to ABF Events. State Associations and individual clubs are not obligated to impose these regulations on their club members, although many choose to do so. ABF System Regulations are not esoteric. They are posted for players at all ABF events and are available for viewing on the ABF Website. Notification of System Regulations are the responsibility of sponsoring organizations.

At club level, it is the club which should undertake this responsibility and directors should be familiar with the regulations in force for events which they are called upon to direct. The specific bid which is cited above is not in breach of any regulations if it is registered with the director as a “Yellow System”. However the use of Yellow Systems is in itself subject to regulation but no restriction would have applied in the ANOT final, which was the subject of the article. In most ABF Tournaments, the lower half of the field is protected against Yellow Systems and, in any case, the legitimacy of opponents’ bidding agreements can be raised with the director, thereby providing added protection.

Note that directors have a responsibility to ensure that players have agreements which conform to the System Regulations but are powerless if non-offenders choose not to call their attention to breaches of these regulations.

Rule Of Sixteen or Rule of 16
The rule of sixteen is similar to the Rule of 15. The player in fourth seat after three passes should count his high card points and add them to the number of Spades in his hand, and if the total is 16 or more, then the player should open, even with less than a normal opening.

Rule of Sixteen or Rule of 16
This guideline or rule is employed by bridge partnerships in determining whether to raise a 1 No Trump opening to 3 No Trump. The responder counts the number of high card points and the number of cards beginning with the 8 and higher. If the sum of the high card points and the number of cards 8 and higher equals the number 16 or higher, then the responder should raise immediately to 3 No Trump or after employment of the Stayman and/or Jacoby Transfer conventional methods. As a result of this, the natural response of 2 No Trump by the responder may be employed for other purposes by the partnership.

Rule of Seventeen or Rule of 17
If the partner opens the auction with a Weak Two bid, the responder should add the number of high card points to the number of trumps in the holding, trumps being the suit of the Weak Two opener. If the total is at least 17 or higher, then the responder should bid game in the suit of the partner. Attributed to Mr. Zeke Jabbour.

Rule of Eighteen - Rule of 18
Only if the number of high card points added to the total of the two longest suits equal 18 plus, then the bid is acceptable by the World Bridge Federation for all sponsored tournaments.

Rule of Nineteen - Rule of 19
In the bridge community of England, the Rule of 19 is the appropriate guideline for determining whether to open the auction in fourth seat following three consecutive passes. The same parameters apply as the Rule of 18 as established by the World Bridge Federation. The number of high card points are added to the number of the two longest suits, and if the total equals 19 plus, then an opening in fourth seat is permitted according to the regulations of the English Bridge Union.

Note: This Rule of 19 is published by the English Bridge Union for agreements by partnerships and members of the English Bridge Union only regulated tournaments, which usually includes duplicate bridge events / games at affiliated bridge clubs. The
Rule of 19 states that an agreement may not be made to open one of a suit on a hand where the number of high card points plus the number of cards held in the longest two suits total fewer than 19.

Rule of Twenty - Rule of 20
This guideline or method, named the Rule of 20, is a method in determining whether a holding containing fewer than the standard 12 plus high card points is, despite this fact, worthy of an opening bid.

Rule of Twenty Two - Rule of 22
This rule is mostly used by those players who open light, and who must make a decision as to whether to open at all. This decision, as it turns out, can have the number 22 as its foundation.

Rule of Twenty Five - Rule of 25
This designation with the write-up is presented online by the Ascot Bridge Club, which is affiliated with the English Bridge Union. This write-up is presented without change in wording or font. This information is only preserved and archived on this site in .pdf file format for future refercne.

Rule of Twenty Six - Rule of 26
Mr. Harold Schogger, who is represented on the Internet at many and various sites, submitted the following Rule of 26, or the TSSSSR, as a contribution to bring this information to the visitors of Bridge Guys. We are thankful to Mr. Harold Schogger and appreciate his contribution very much. We have included this Rule of 26 verbatim and have changed nothing



If you wish to include this feature, or any other feature, of the game of bridge in your partnership agreement, then please make certain that the concept is understood by both partners. Be aware whether or not the feature is alertable or not and whether an announcement should or must be made. Check with the governing body and/or the bridge district and/or the bridge unit prior to the game to establish the guidelines applied. Please include the particular feature on your convention card in order that your opponents are also aware of this feature during the bidding process, since this information must be made known to them according to the Laws of Duplicate Contract Bridge. We do not always include the procedure regarding Alerts and/or Announcements, since these regulations are changed and revised during time by the governing body. It is our intention only to present the information as concisely and as accurately as possible.