Doubles and Redoubles - Every bridge player employs the call of double, but the meaning can be different in many cases. The call can be different from partnership agreement to partnership agreement, and the call can actually change in meaning during the auction. The attempt has been made to present a list of officially designated doubles, which have been designed and developed over the years of the evolution of the game of bridge.

Experienced bridge players, bridge theorists, and bridge pioneers have devised, developed, defined, and even modified such tactics for the bridge player. The command of this basic feature is a fundamental knowledge and a priority for all bridge players.

This call has so many meanings in the game of bridge, and a quantum of ambiguity among players is practically a given and understandable. The call of double is the subject of many bridge-related articles and the requirements are perhaps not always written or etched in stone. However, the attempt is made to provide guidelines, according to which the call can and should be made.


The following calls are all employed in some conventions and treatments, and this call must be understood by your partner. Therefore, a partnership agreement is essential.

It cannot be maintained that each double is unique, but every time this call is made, certain defined interpretations and understandings accompany it.

In time, there will be yet more doubles, and yet more interpretations, and yet more understanding of their meanings. But we leave that to the future, and shall deal now only with the present.

Following are a few officially designated doubles, but the list is by no means complete.

Active Double
This is a call employed in competitive auctions, which strongly implies additional offense strength in case partner may wish to continue to compete. This particular double also indicates strongly the willingness to defend the contract of the opposing side.

Bubble Double
This designation is from the Dutch bidding system, commonly referred to as MAF or M.A.F., which is an acronym that could have several different translations such as: Majors Always First or Multi's Are Favorite, and stands for two its characteristic properties. The dutch word "maf" (or "maffe" as adjective to nouns in certain cases) may be an adjective or an adverb. This word is used when English-speaking people would say "sluggish(ly)", "queer(ly)","dul(ly)", or  "funny (funnily)". As a matter of fact maf is all four jointly, so the translation is also really "maf" indeed.

The Bubble Double is employed after Weak No Trump openings and other openings that bubble up out of empty hands such as the Precision 1. It signifies at least one 4-card Major suit and fewer than 10 high card points, and denies a 5-card suit. If the partner of the doubler passes, then the partner converts the double to a penalty double. Otherwise the partner will bid.

Business Double
This designation is / was often employed in early stages of the game of bridge to designate a low-level penalty double. However, the circumstances are that the opposing side makes an opening bid, partner doubles for takeout, and the advancer converts the takeout double for penalty. Frequently the final score would be greater than had the partnership competed for either a partscore or even a game contract. An example follows.

1   Double   Pass   Pass This pass by South converts the takeout double to a business double.

Competitive Double
The Competitive Double was designed to allow the bridge player to invite partner either to bid game, to give partner the chance to sign off in a partscore, or to simply pass for penalty.

Cooperative Double
A cooperative double is a double that provides the partner the option, information for deciding to, or the opportunity of passing for penalties or to continue bidding.

Cuebid Double
A double that sends the same message a cuebid would have sent had the intervening opponent not bid. For example: 1 Club - 1 Spade - 2 Clubs — Double used with the same fundamental meaning as 1 Club - 1 Spade — pass - 2 Clubs. This concept was devised by Mr. Marshall Miles, who used the following example:

West North East South
1 2 Double Pass
2 Pass Pass 3
Pass Pass Pass

The double of East is the equivalent of cuebidding 2 Diamonds. East could not cuebid because the immediate opponent bid the suit first. Because East has only 3-card support in Spades, East uses the cuebid double instead of bidding directly 3 Spades, which in the method employed by Mr. Marshall Miles, would show an invitational raise with at least 4-card support.

To use this method, the defenders give up either the natural penalty double or the responsive double. However, Mr. Marshall Miles states that the cuebid double will come up more often and be more useful. Employing this method, South’s bid of 3 Diamonds promises either additional values in shape or additional values in strength.

Delayed Double
This is a term for the call of double by a player, who has passed previously in a competitive auction. The significance of this double can have different meanings as established by the partnership agreement, such as penalty or as one-round forcing.

Dobi Double
These doubles were originated with Mr. Melih Öhdil of Turkey. Source. According to the author the doubles were named in memory of his lovely dog Dobi. These doubles are employed following an opening by the opposition of a strong 1 No Trump.

Do Something Intelligent Double
The shortened abbreviation for this double is DSI, which refers to a double by one opposing player meaning that partner should do something intelligent. Essentially the double refers to a low and even a high-level double, which shows / promises cards and is properly considerd cooperative. The player, in a competitive auction employs this type of double when there is no clear action possible otherwise. The exchange of information, however, does not refer to a penalty double, but rather to determine the best action to be taken in the continuation of the competitive auction.

Fisher Doubles
This is the designation for a lead directing double of a No Trump game contract asking for a Minor suit lead, developed by Dr. John Wyatt Fisher, Jr. M.D. of Dallas, Texas, United States. The concept of the Fisher Double is that the opponent, who is not on lead, doubles for the lead of a certain suit, either Clubs or Diamonds.

Informatory Double
Once used to describe what is now the Takeout Double. This term was first applied to a Takeout Double and was employed as such. The designation lost its significance over time as the game evolved.

Inhibitory Double
A psychic maneuver in a competitive auction. The goal is to intimidate the opponents. The Inhibitory Double can also take the form of a double of a forcing bid after one partner has already overcalled as in the following example: 1 Heart-2 Clubs-2 Spades-double. Normally, the 2 Spades bid by the partner of the opener is forcing in standard style. The doubler should indeed have a very poor hand but with moderate support for his partner who overcalled with 2 Clubs. The double can also show length in the fourth unbid suit Hearts, as in the Snapdragon convention.

Lead Directing Double
The employment of this double enables one partner, who is not on lead, to lead a certain and particular card against either a No Trump contract or a suit contract.

Liberty Double
The Liberty defense mechanism versus the Multi offensive mechanism is used when the opponents opening bid has multiple weak possibilities with no known suit. This defense mechanism is designed to increase the possibility of penalties while also providing, at the same time, some blocking bids. The main feature is the Liberty Double made directly over the Multi bid.

Lightner Double
The lightner double is a lead-directing double made by the defender not on lead of a slam contract. The concept was developed by the bridge pioneer Mr. Theodore A. Lightner in the year 1929.

Low Level Doubles
This information has been authored by Mr. Larry Cohen and posted on his Mr. Larry Cohen also refers to these doubles also as DSI Doubles, which means that the player should Do Something Intelligent. He also admits to designations such as Card-Showing or Cooperative.

Maestro Doubles
This conventional method is used after an opponent opens the auction with 1 No Trump. The range of the No Trump does not affect the effectiveness of this conventional method. However, it should be kept in mind that this particular conventional method is mostly employed by those partnerships employing No Trump defenses along the line of and similar to Hamilton, Cappelletti, and/or especially Astro in any form.

Maximal Doubles
The official designation is maximal double as described in The Official Encyclopedia of Bridge authored by the American Bridge Contract League, Edition 6, page 289. The identical concept is also official designated as maximal overcall double by other authoritative and sponsoring bodies since this type of double only occurs in competition and generally for only two specific bidding sequences. The designation maximal double overcall is also employed to describe this concept.

Mini-Lightner Double
The origin of this conventional method is unknown. As with the original concept of the lightner double, the mini-lightner double can be employed at the four and at the five level in the game of bridge. This is generally the case when the opponents see the strong possibility of a suit contract being declared.

Negative Double
Mr. Alvin Roth and Mr. Tobias Stone developed the Roth-Stone system, which included the negative double and which also defined the present day parameters of this particular double. The original designation was Sputnik, named for the Russian satellite launched by the Soviet Union October 4, 1957.

Off Shape Takeout Double
Also designated as Minimum Off Shape Takeout Double. This is basically a takeout double made with a holding, which does not correspond to the traditional shape or pattern for a takeout double.

Optional Doubles
The origin of the optional double is unknown and has been modified since the first concept. The optional double, which is generally considered a cooperative double, is used to show a specific shape and a minimum of points to defeat the final contract of the opponents in all probability, and promises support for the partner for any unbid suit. This optional double provides the advancer with the option of either passing for penalty or continuing to compete.

Panther Double
Described, devised, promoted, and published by Mr. Zia Mahmood in the year 1993. The panther double is considered a psychological double, which may cause the opposing side to consider a less secure contract. As the prey runs from the panther, so may the opponent run from the better contract. The presentation is in .pdf file format, which will be automatically opened in a new window. This informatilon can be found on the Internet and has only been archived and preserved on this site in .pdf file format for future reference.

Parking Lot Redoubles
The source for this particular double is The Bridge World, June 1987, Volume 58, Number 9, and authored by Mr. Jerold (Jerry) Fink.

Penalty Double
The origin of the penalty double is unknown. However, it is known that the penalty double is older than the organized game of bridge with its scoring methods devised in the late 1920s and early 1930s. In the card games preceding such scoring methods the penalty double was effective in acquiring a larger score and was mainly devised to painfully punish their opponents for their audacity in competing.

Responding Doubles of 1NT Responses and Rebids
This is a contribution of Mr. Marvin French of San Diego, California, United States, to whom we are indebted. This is a revised version of the original article, which appeared in Popular Bridge magazine of June 1977, and in The Bridge Bulletin of ACBL in February 1995, page 93. This information is presented in .pdf file format and will be automatically opened by your browser in a new window.

Responsive Doubles
This concept was devised by and originated with Dr. F. Fielding-Reid of Dania, Florida, United States. After an opening, a takeout double by partner and a two- or three-level raise by the partner (responder) of the opener, the partner (advancer) of the takeout doubler can also double, thereby providing and communicating descriptive information about his hand. This action is known as a responsive double.

Sohl Doubles
The origin of this call of double is unknown, but it has been rumored to be a double employed at colleges and universities, especially in The Netherlands. The origin for the designation for this double is also unknown, but is believed to be the surname of a bridge player and has no relation to the lebensohl conventional method. Source is from website for the M.A.F. (MAF) Bidding System located on the web and in The Netherlands.

Snap Dragon Doubles
During its course of development and/or employment this concept it also acquired the designation of Fourth Suit Double. The reason for this designation is that the Snap Dragon Double can only be triggered by the player in the fourth seat after the three previous players have bid a suit.

Stripe-tailed Ape Double
In the days of yore when the scoring methods of the game of bridge was evolving a certain Mr. Sam Scaffidi in cooperation, collaboration and possible conspiracy with Mr. John Lowenthal discovered that if the opponents doubled at the five level when the other two players were definitely heading towards a makeable slam contract, then the slam bidders might possibly consider playing at the five level doubled.

Sucker Double
The sucker double is not a conventional method, competitive or otherwise, but rather a tactic employed by a player. It is the designation of a freely bid game or slam contract by a player, who relies completely on defensive high card strength. A disadvantage to such a double is the fact that the double seldom results in more than perhaps a small profit when played against good opponents. Conversely, the end result can result in a complete disaster for the partnership when the double assists the declarer to make the contract by finessing, for instance, the player, who doubled. However, it will prove more the case that the declaring side has unknown distribution strength, or even a void to compensate for the lack of high card points.

Support Doubles - Support Redoubles
The concept of the support double and also the support redouble was devised by Mr. Eric Rodwell, and is a method that enables the opening bidder to clarify or show precisely the degree of support of the suit of the partner or responder. This generally occurs in a competitive auction, in which an opponent interferes at a low level.

Takeout Double
This is the designation for a low-level double in certain circumstances requesting partner to bid an unbid suit. Doubling on the one-level and giving it the interpretation of a penalty double is certainly neither reasonable logic nor reasonable bridge.

Strategic Double
According to the publications of Mr. Ely Culbertson, who introduced the designation into the game of bridge in the early 1930s, a strategic double promises 3 honor tricks with strength distrubuted in three suits or in at least two suits with a fair biddable suit. This terminology is no longer employed.

Responses to a Takeout Double by Your Partner
The responses to a takeout double are dependent upon the situation. For example, the situation must be clear as to whether the advancer has previously passed or whether has the responder bid over the takeout double. The more preferred responses are presented to the bridge player and these responses are based upon the holding itself.

Thrump Doubles
Instead of describing the Thrump Double independently the author contributed this informative description.. The following description is by Mr. Marty Bergen, who invented and devised the Thrump Double and its application. In case the visitor or bridge student would like to contact Mr. Marty Bergen, he/she can do so by visiting the (website) of Mr. Marty Bergen.

Tolerance Redoubles
This is the designation used for an action in a competitive bidding situation devised by Mr. John Ross and which was published in the year 1997 in the magazine The Bridge World, issue May 1997, page 28.

Note: The concept is also known under the designation of Munson, which was devised by Kitty Munson Cooper, and which is sometimes referred to as tolerance redoubles. The redouble promises shortness, as in one or two cards maximum, including the Ace or King. Following the redouble the overcaller's spot-card lead in his overcalled suit is suit preference for the side suit, to which a shift should be made.

Unpenalty Double
The origin of this action is unknown. This is the terminology for a conventional double, whereby the double of a slam contract promises no defensive tricks. This action permits the partner to judge more accurately whether to sacrifice. The general guideline is that with one or more defense tricks, the partner



If you wish to include these features, 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.