Conventions overview

In this section, you will find all the conventions that can be selected in Jack. Their descriptions are brief. For more thorough discussion, consult bridge literature, such as the ACBL's Official Encyclopedia of Bridge or Amalya Kearse's Bridge Conventions Complete.

Acol strong two

2, 2 and 2 openings are strong, promising eight or nine tricks. Game-forcing hands and strong balanced hands with at least 23 HCP are opened 2.

Acol two clubs

2 is artificial and forcing, showing a hand strong enough to force at least to within one trick of game, and usually stronger. This 2 opening is typically combined with Weak two bids in the other suits, or Multi 2 and Muiderberg.


A conventional defence after the opponents open 1NT, available in both the direct and passout positions, using these artificial overcalls:


A conventional defence after the opponents open 1NT, available in both the direct and passout positions, using these artificial overcalls:

With five spades and four or five hearts the correct Asptro bid is 2, with five hearts and four spades the correct Asptro bid is 2.


A conventional defence after the opponents open 1NT, available in both the direct and passout positions, using these artificial overcalls:

Australian Stayman

2 asking bid after a 1NT opening.

Opener responses:
2 minimum with 4-4 in the majors
2 minimum with four hearts and not four spades
2 minimum with four spades and not four hearts
2NT minimum, no four-card major
3 maximum, no four-card major
3 maximum with 4-4 in the majors
3 maximum with four hearts and not four spades
3 maximum with four spades and not four hearts


3 after partner has opened 2NT. Opener bids a five-card, or his cheapest four-card, suit.

Benjamin opening

In the Benjamin complex, the 2-opening is the traditional Acol strong two and the 2-opening is game-forcing. The cheapest response, 2 to 2 or 2 to 2, is artificial and negative.

Note: The auction 2 - 2 - 2NT shows a balanced 23-24 HCP and is not forcing.

The Benjamin 2 and 2 openings can be combined with various meanings for 2 and 2, like Muiderberg or Weak two.

Bergen raises

A scheme of support-showing responses to first- and second-seat (five-card) major-suit openings:

This convention can be combined with Jacoby 2NT and splinters to show game-forcing hands with four-card support.


4NT asks for aces or key cards. There are several Blackwood variations. The most popular is Roman Keycard Blackwood.


A conventional defence after the opponents open 1NT, available in both the direct and passout positions, using these artificial calls:


A conventional defence after the opponents open 1NT, available in both the direct and passout positions, using these artificial overcalls:

Checkback Stayman

After opener rebids 1NT, 2 is artificial, promising at least invitational values and asking opener to show undisclosed major-suit length. See also New Minor Forcing, Ping-Pong and Roudi.

Competitive double

A double that is not for penalties, but shows a hand too strong to pass that has no descriptive bid.


A conventional defence after the opponents open 1NT, available in both the direct and passout positions, using these artificial calls:


A method for coping with intervention over Blackwood.

In Roman Keycard Blackwood, of course, key cards rather than aces.


An artificial 2 response by a passed hand that asks a major-suit opener if he has full values. A 2 reply by opener shows a shaded opening. See also Reverse Drury.

Ekren 2

A conventional 2 opening that shows 5-11 HCP and 5-4, 5-5 or 6-4 in the majors. There are many variations. A 2NT response asks for further description as shown in the chart below.

Note: in fourth position Ekren 2 shows exactly 5-5 in the majors and 10-12 HCP.

Opener's rebids after a 2NT response:
2 - 2NT



HCP = 5-9, unknown 5-4 in the majors


HCP = 5-9, 5-5 in the majors


HCP = 5-9, 6-4 -


HCP = 5-9, 6-4 -


HCP = 10-11, unknown 5-4 in the majors


HCP = 10-11, 5-5 in the majors


HCP = 10-11, 6-4 -


HCP = 10-11, 6-4 -

After a 3 or 4 reply, responder's 3 or 4 rebids asks opener to bid his five-card major.


The conventional use of jump shifts in competition to show the suit bid plus a fit for partner's suit; forcing for one round.

Flannery Two Diamonds

A 2 opening that shows 11-15 HCP with five hearts and four spades.

Flex 2 rebid

After an openingsbid of 1 or 1 opener can rebid an artificial 2. He has either clubs as a second suit or any strong gameforcing hand (onesuiter or twosuiter with the major he opened). Responder can ask for clarification with 2. This convention can only be used if the opponent do not overcall.


A weakness-showing 3 response to a 2NT opening that asks opener to bid 3 and is used to stop below game in a long suit. Responder passes or corrects to his suit if other than hearts. Opener may 'super-accept' hearts by bidding 3.

Fourth suit forcing

Responder's fourth-suit bid is forcing and presumably artificial, often used to create a further force when responder next bids three of a suit that has been bid previously by either partner.

Gambling 3NT

A 3NT opening based on a long solid minor. Opener has at most one queen in the other suits.


The use of 4 to asks for aces (or key cards) in auctions where 4NT would be quantitative.


A system of overcalls to show two-suiters.

Ghestem, modified

Like Ghestem, but with one exception. After 1, the Ghestem overcall to show the majors is not 3 but 3. This leaves 3 available for use as an intermediate jump overcall or weak jump overcall.

Good-Bad 2NT

A conventional use of 2NT in competitive auctions to distinguish between better and worse hands. As in the Lebensohl-convention, direct three-bids are stronger than the same bids mediated by 2NT bid. The 2NT bidder urges his partner to bid 3, which he'll usually pass or correct to his suit if other than clubs, but partner must take care not to bid 3 with a preference for a suit the 2NT bidder has bid earlier, or with any other hand not content to play in 3 facing a minimum hand with clubs.

Intermediate jump overcall

A single-jump overcall that is used to show a good one-suiter with sound opening-bid strength (usually 11-15 HCP).

Inverted minors

The use of a simple raise of a minor-suit opening in an uncontested auction as forcing, promising limit-raise values or better (at least 11 support points) in conjunction with weak jump raises.

Inverted minors in competition

After an intervening overcall in a suit, the treatment of a jump raise of opener's minor as weak and the single raise as forcing (promising limit-raise values or better). See Inverted minors.

Jacoby Transfers

The use of a minimum response in diamonds to show at least five hearts, and a minimum response in hearts to show at least five spades, after a natural opening in notrump (or opener's notrump bid as the first natural bid of the auction). Opener normally bids the major suit shown by responder at the lowest level, but may 'super-accept' with a fit and excellent values. The main advantages are letting the strong hand become declarer and assuring responder another turn to describe his hand further.

Jacoby 2NT

The use of a 2NT response by an unpassed hand as an artificial forcing raise (game values and four-card or longer support) to a major-suit opening. Several versions exist. In the most popular, responder denies shortness (by failure to splinter) and asks opener to show shortness in reply.


A conventional defence after the opponents open 1NT, available in both the direct and passout positions, in which 2 shows the majors. A 2 reply may be used to ask overcaller to bid his longer (or stronger if equally long) major.


The conventional use of a defender's first discard as discouraging in that suit and showing suit-preference between the other two suits (high showing the higher of the two, low showing the lower).

Leaping Michaels

Conventional 4 and 4 jump overcalls over opposing Weak 2 and 2 openings, showing strong two-suiters with the bid minor and the unbid major. This replaces the standard Michaels Cue Bid, and allows the cue bid to be used as a request for partner to bid 3NT with a stopper (presumably because the cue-bidder has a running minor suit).


A structure for showing different grades of hand after an opponent bids two of a suit over partner's 1NT. Three of a suit is forcing. With a hand not good enough to force, responder bids 2NT. Opener must reply 3, which responder passes with long clubs or corrects to his long suit if other than clubs. This 2NT response is also used to distinguish hands that have a stopper in overcaller's suit from hands that do not. In the most popular version, responder's direct jump to 3NT, or cue bid in overcaller's suit, denies a stopper, while the same bid mediated by 2NT shows a stopper. Note that when responder bids 2NTand follows with three of a suit higher than the suit bid by overcaller, he is inviting game. Good Bad 2NT works somewhat differently but is based on the same principle.

Michaels Cue Bid

A cue bid in a minor shows the majors and as played by most is based either on a hand with somewhat less than opening-bid strength or a very strong hand ; a cue bid in a major shows the other major and an unspecified minor for which partner can ask by bidding 2NT.

Minor-Suit Asking

A conventional use of 3 and 3 rebids by a Stayman bidder to show interest in a minor-suit slam. 3 ASKS about the minor suits of the 1NT bidder and is used on responding hands with a four-card minor; 3 SHOWS a five-card or longer minor.

Minor-Suit Stayman

When you play Jacoby Transfers, you do not need a natural spade response to a notrump opening. One popular treatment is to use 2 to ask a 1NT opener to bid a four-card minor if he has one, and 3 to ask a 2NT bidder for a four-card minor (implying slam interest).



An opening-lead convention, scorned by experts such as Mike Lawrence (author of the best book on Opening Leads),in which the middle ('M') of three low cards in a suit is led first, followed by the highest ('U' for 'Up') on the opening leader's next play in the suit and finally the lowest ('D' for 'Down').


A typical Dutch convention in which a 2 or 2 opening shows five cards in bid major and at least four cards in an unspecified minor with about 5-11 HCP.


A conventional defence after the opponents open 1NT, available in both the direct and passout positions.

The 2 overcall resembles a Multi 2 opening, the 2 and 2 overcalls are analogous to Muiderberg.

Multi-Landy (double)

A conventional defence after the opponents open 1NT, available in both the direct and passout positions. To Multi-Landy, add a double that shows an unspecified four-card major and a longer minor. Called 'Woolsey' in the United States after its inventor.

Multi 2

An opening bid of 2 which can be based on a Weak Two-Bid in either major or a balanced 25-26 HCP hand. Responder replies 2 for opener to pass or correct to spades with a Weak-Two hand, or 2 to show a raise of hearts (only). 3, 3 and 4 responses are similarly 'for correction'.

Strong responses include 3 or 3 (natural, game-forcing and short in both majors) and a 2NT relay (14 HCP or more), to which opener replies:

3 = weak two in hearts, minimum
3 = weak two in spades, minimum
3 = weak two in spades, maximum
3 = weak two in hearts, maximum
3NT = 25-26 NT
The Biedermeier convention cards swap the meanings of opener's 3 and 3 replies.


A conventional use of 4 to show a 'strong' 4 opening and 4 to show a 'strong' 4 opening.

Negative Double

A conventional takeout double by the responder to an opening one-bid following an intervening overcall in a suit; promising at least four cards in an unbid major (when there is one), both minors when only majors have been bid, both majors when the overcall is 1, exactly four spades (as most play it) when the overcall is 1. After a 1NT opening, many pairs use Negative Doubles of three-level overcalls, some also of two-level overcalls. Pairs that use Negative Doubles must agree to which overcalls they apply (most commonly, to overcalls through 3).

Negative Free Bids

Some pairs reverse the treatment of doubles and new-suit responses over intervening suit overcalls. Playing Negative Free Bids, a new-suit response shows at least five and is non-forcing (7-11 HCP). With a better hand, responder must start by making a Negative Double.

New Minor Forcing

A variation of Checkback Stayman in which after a 1 opener rebids 1NT, responder's 2 (promising at least invitational values and asking opener to show undisclosed major-suit length) is used as the artificial inquiry, allowing 2 to be played as weak and natural. See also Checkback Stayman, Ping-Pong and Roudi.


OBARBIDS stands for 'Opponents Bid And Raise, Balance In Direct Seat.' Using this treatment, you can double or overcall on shaded values after a simple raise of an opening bid to two.


A conventional use of a 2NT response to a weak two that asks opener to indicate the quality of his hand and his suit.

Rebids by opener after 2NT (but note that many pairs swap the meanings of 3 and 3 replies):
2/2 - 2NT



Minimum with a bad suit


Maximum with a bad suit


Minimum with a good suit


Maximum with a good suit


After opener rebids 1NT, 2 is conventional and forces opener to bid 2. Responder can now rebid his major (a one-round force showing at least invitational values) to seek three-card support and inquire further as to opener's strength. See also New Minor Forcing, Checkback Stayman and Roudi.

Protective double

Another name for a balancing takeout double, often made liberally by opener when playing negative doubles, in hopes of catching partner with a penalty pass.

Puppet Stayman after 1NT

2 asks opener for a four-card or five-card major suit. Responder shows at least invitational values. See the 3 response in the Puppet Stayman (Dutch variation) below.

Puppet Stayman (Dutch variation)

After an 2NT opening responder has the following options:

In reply to 3, opener rebids 3 to show at least one four-card major and 3 or 3 to show a five-card major.
If opener rebids 3 responder may continue:

Quantitative 4NT

Any natural 4NT bid that shows more than game values and therefore slam interest. The standard meaning of notrump raises.


A cheap artificial bid that asks partner for further information.

Responsive Doubles

Conventional double after a takeout double by partner and a raise of opener's suit by responder. A responsive double over a minor shows both majors, a responsive double over a major shows both minors. Also used by many as takeout for the unbid suits after an overcall and responder's raise. Each pair must decide through what level to play responsive doubles.

Reverse Drury

An artificial 2 response by a passed hand that shows a limit raise of opener's major. A 2 reply by opener is artificial and promises at least some game interest. To reject game, opener rebids two of his major, or (in some partnerships, two of a lower four-card major). See also Drury.


A convention method of discarding to show suit preference. A high card asks for the higher-ranking suit, a low-card for the lower ranking suit. The trump suit is skipped and the other suits are treated as a circle, so a high spade shows clubs or, if clubs are trump, diamonds.

Roman Keycard Blackwood

In this Blackwood variation, the king of the trump suit is counted as if it were an ace, so there are five 'keys,' and provision is made for showing the queen (or nearly equivalent extra length) in the trump suit.


Another version of Checkback Stayman.. After opener rebids 1NT, 2 is artificial and asks for more information. The 2 bidder has at least invitational values and is usually seeking three-card support in his major. See also New Minor Forcing and Ping-Pong.


A convention that employs transfer bids starting with 2NT after an opponent overcalls partner's 1NT opening. A transfer 'into' overcaller's suit serves as a Stayman request for an unbid four-card major. 3 is forcing to game but denies four cards in an unbid major and denies a stopper, so that a jump to 3NT implies a stopper in overcaller's suit. An improved version swaps the meanings of 3 and 3 when the overcall is 2.


'RUNT' stands for 'Really Unusual No Trump,' a 1NT overcall that shows a light (9-11 HCP) takeout double with 9-11 HCP and requires the abandonment of standard 1NT overcalls showing strong balanced hands with stoppers.


An opening-lead convention in which from two or more touching honors the second-highest rather than the highest is normally led.

Sandwich Notrump for Takeout

The conventional use of a 1NT overcall after both opponents have bid as a distributional takeout showing the two unbid suits, thus reserving a takeout double for hands with more high-card strength and (usually) less shape.


A convention that swaps the meaning of responder's 3 and 3 rebids after a 1NT or 2NT opener denies a major in reply to Stayman, so that each shows (at least) game values with five cards in the unbid major while implying four cards in the major that responder bids. The purpose and effect is to let the strong hand declare when a 5-3 fit in the unbid major exists.


A double-jump in a new suit, or four of opener's minor, that shows primary support for the last-bid suit and shortness in the suit of the jump. When you play 'reverses' as forcing (the modern treatment), you can use a single-jump reverse as a singleton splinter so that a double-jump reverse can be a void splinter.


An artificial response to notrump openings (or notrump bids as the first natural bid) that uses the cheapest club bid to ask opener to bid a four-card major if he has one. There are many versions, but in the standard version, responder promises at least one four-card major. Most modern pairs play that with two four-card majors, opener replies in hearts.


A version of Stayman in which the 2 response to a 1NT opening does not promise a four-card major himself. This version enables pairs that use a direct 2NT 'raise' artificially replace the natural 2NT raise by a 2NT rebid following the reply to Stayman.

Stayman with 2NT (or 3NT) reply

A version of Stayman in which opener rebids in notrump when he has two four-card majors. Responder, who presumably has at least one four-card major, can then transfer to the major suit in which he wants to play.

Support Doubles and Redoubles

A conventional double by opener that shows a three-card raise, perhaps with extra strength, of responder's major after the next player makes a non-jump bid at or below the level of 2, allowing explicit raises to promise four-card support. Each pair must decide in which auctions Support Doubles apply. Do they apply to 1NT overcalls and overcalls in opener's minor? Do they apply to raises of overcalls and replies to takeout doubles? Most pairs that play Support Doubles also use opener's redoubles of takeout doubles with the same meaning. Opener's failure to make a Support Double or Redouble when applicable suggests (but does not guarantee) fewer than three cards in responder's major.

Texas Transfers

The use of 4 as a transfer to 4 and 4 as a transfer to 4 in response to 1NT or 2NT openings.

3 as Puppet Stayman after a 1NT opening

The use of a jump to 3 to ask for a four-card or five-card major in response to 1NT. See Puppet Stayman (Dutch Variation).

Transfers to minor suits

Many versions are possible, but in the most popular, a 2 response to 1NT shows clubs and a 2NT 'raise' shows diamonds. Some play that opener can show excellent support for responder's minor by rejecting the transfer and making the cheapest bid instead in reply. (Pairs that use minor-suit transfers in this way also play Stayman-relay to handle responding hands that merely want to invite 3NT.

Transfers to minor suits after 2NT

Transfers to minor suits after a 2NT opening (or first natural bid) are usually simpler, 3 showing clubs and 4 showing diamonds, as few are willing to play a 3NT 'raise' as artificial.


The 2NT jump-response over an intervening double of partner's suit opening is commonly played as showing a limit raise (or better).

Unusual NT

A popular conventional use of a 2NT jump overcall, usually based on a distributional hand with little defensive strength but sometimes based on a very strong hand, to show the two lowest unbid suits.


After a 1 opening responder bypasses a four-card or longer diamond suit with less than game values in order to bid a four-card major regardless of suit quality. In conjunction with this treatment, after 1 - 1 opener rebids 1NT routinely with a balanced hand and a four-card major, relying on responder to introduce a four-card major if he has one, so that opener's major-suit rebid always shows an unbalanced hand.

Weak jump overcall

The treatment of jump overcalls as weak and mainly obstructive. A commonly-used range in high-card-point terms is 5-9, but players vary according to personal style.

Weak jump shift

The treatment of jump-shift responses as weak, promising a long suit while denying sound responding values.

Weak jump shift in competition

The treatment of jump-shift responses as weak over intervening overcalls.

Weak Two-Bids

The treatment of some or all opening two-bids (excluding 2 and in many partnerships also excluding 2) as showing somewhat less than normal opening-bid high-card strength but with a good six-card suit. Standards for Weak Two-Bids vary greatly.

Weak 2 and 2 with five- or six-card suits

A 2 and 2 opening based on 6-11 HCP and five or six cards in the opened suit. With a strong hand responder can bid 2NT to ask for more information.

Note: in fourth position 2 and 2 show six-card suits and 10-12 HCP.

Openers rebid after 2NT:
2/2 - 2NT



6-8 HCP and five cards


6-8 HCP and six cards


9-11 HCP and five cards


9-11 HCP and six cards