In the early days of the evolution of the game of bridge the bridge players in England adopted the concept of opening the auction with a bid of 3 No Trump. The parameters of this opening bid were not exactly precise, although defined to a certain degree. It is from this concept that the Gambling 3 No Trump conventional method is derived.

Note: The conventional method of Gambling 3 No Trump is presented elsewhere and only the Acol version of this opening bid is described below. The present concept of Gambling 3 No Trump is the result of expanding, extending, and modifying the original concept with additional features, which can vary between partnerships.

The parameters for an opening Acol 3 No Trump bid is that the bid promises a seven-card or longer Minor headed by the AKQ, and no more than a Queen and a Jack outside the Minor suit. The following example presents a holding meeting all the requirements for an Acol 3 No Trump opening bid in its most early version.

Acol Three No Trump Opening Bid
South A6 K7 J3 AKQJ854
Bid		Meaning
3 NT		In the most early version the bid promises a long, solid Minor suit with stoppers in at least two side suits.

The reader should take note that an opening bid of 3 No Trump does not promises a range of 25-27 high card points, balanced distribution, and game. In order to show such a holding the partnership agreement is to bid as follows.

Acol Three No Trump Opening Bid
South AKJ KQ9 QJ98 AKQ
Bid		Meaning
2		An opening bid with multiple meanings as defined by the partnership. This is generally considered to be an strong, artificial, and one-round forcing opening bid. The partner may not pass.
3 NT		Whatever the response method is of the partnership a rebid by the opener of 3 No Trump promises a range of 25-27 high card points, balanced distribution, and game.

Parameters

The concept of a 3 No Trump opening bid has not been definitively established. Rather the parameters were set by the partnership. Therefore, partnership agreements regarding the amount of outside strength differed considerably. One version is that there be absolutely no outside strength and other agreements insisted on at least stoppers in two outside suits.

It is of note that the partnership agreement remained valid in second seat following an opening by an opposing player. Another variation of the concept included the fact that the agreement could be separately defined if the opening 3 No Trump bid were made in the fourth seat. The following example shows the multiple agreement of the partnership, whose understanding is that the opening bid promise at least two stoppers in side suits.

West		North		East		South
Bid								Meaning
Pass		Pass		Pass		3 NT		An Acol 3 No Trump bid in fourth seat, which promises only a long Minor suit and no outside stoppers in any of the other suits. Note that this is the agreed understanding, not the actual holding.
						84 Q6 AKQJ753 103

One unalterable, immutable, and inflexible agreement regarding the concept is that no agreement should or would permit the 3 No Trump opener or overcaller to have a void in any side suit. This agreement was later expanded to include the understanding that the holding also contain no side singleton unless the singleton were the Ace of that side suit.

Note: The above definition has been altered by partnerships over the years to include the holding of a singleton even if the side suit singleton is not the Ace.

Responses

The following response method is from the new, revised, and expanded edition of The Official Encyclopedia of Bridge, as published by the American Contract Bridge League in the year 1971.

4 :	Shows extreme weakness and the wish to play at the four level in the suit of the opener. If the suit of the opener is not Clubs, then the opener corrects to Diamonds and the responder passes.
4 :	This response is forcing for at least one round. There are several agreements as to the partnership continuances. One agreement is that the opener bid his longer Major suit holding in order to comply with the forcing bid. Any rebid by the responder is then considered to be a slam try or at least slam invitational.
4:	This response is natural and shows an independent and self-sustaining Heart suit. The opener is requested to pass.
4 :	This response is natural and shows an independent and self-sustaining Spade suit. The opener is requested to pass.
4 NT:	In the most early version this bid is conventional since any and all responses must be down graded owing to the fact that the opener has shown with the opening bid the possession of one Ace. Therefore, a response by the opener to 4 No Trump, asking for Aces, of 5 Clubs shows 1 Ace; a response of 5 Diamonds shows 2 Aces; a response of 5 Hearts shows 3 Aces.
5 :	Over a 3 No Trump opening bid this bid can show, by partnership agreement. the wish to play in a game contract of the suit of the opener. If the suit is Clubs, then the opener passes; if the suit is Diamonds, then the opener corrects. (Note: a second attached definition is that the bid is preemptive in nature and offers the partnership a probable and profitable sacrifice.
5 :	This response is natural and establishes the final contract. The reason behind this first response is the fact that the responder holds an honor, either the Ace, King, or Queen, in Clubs. This fact allows the responder to deduce that the long Minor suit of the opener cannot be Clubs and therefore must be Diamonds.
6/7 :	The responder bids either a small slam or the grand slam in Clubs. The opener either passes if the long Minor suit is Clubs, and corrects if the long Minor suit is Diamonds.

Defense Method

Although the concept of the Acol 3 No Trump opening bid is rarely employed in the more present-day bridge community, the presentation of a defense method to such an opening bid as defined above is mandatory. The following defense method is only a suggested and recommended method, which has been accepted by most sponsoring organizations. To some degree this defense method has similarity with the Astro conventional method, which is employed as a defense method following either a weak or strong No Trump opening bid.

Double:	A double is for penalty and partner must pass.
4 :	Promises Hearts and an unspecified Minor suit, specifically the Minor suit not intended by the opener. The advancer, or the partner of the overcaller, relays with 4 with insufficient support in Hearts and better support for the unspecified Minor suit. The overcaller then bids the unspecified Minor suit. With Heart support the partner bids Hearts.
4 :	Promises Spades and a second unspecified suit. The Advancer, or the partner of the overcaller, relays with 4 with insufficient support in Spades and better support for the unspecified second suit. The overcaller then bids the second suit. With Spades support, the partner bids Spades.
4 :	Natural. To play. Non-forcing.
4 :	Natural. To play. Non-forcing.

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.