The Acol Bidding System is not a Standard Bidding System as the Five Card American Standard Bidding System. This means that the Acol Bidding System is rather interpretable and allows a stronger latitude in flexibility according to the partnership agreement. We would like to present a General Structure of the Acol Bidding System in order that the bridge player, who would like to learn, has a general concept of the meanings behind the bids.

The General Structure of the Acol Bidding System

Opener: With 5+ card suits, open the higher ranking longer suit
  With only 4 card suits, such as a 4-3-3-3 distribution, open the 4 card suit. If you wish to guarantee a 5-card 1 Spade opener, the opener will then open 1 Club with 4 Spades, and this is the only situation when you will only have 4 Spades.
  with a 3-4-4-2 touching distribution, open the higher suit. The exception is when your holding are Hearts and Spades as in the distribution of 4-4-2-3, and the general rule is to open 1 Heart.
  with a 4-4-1-4 distribution, open the suit immediately below the singleton. The exception is the 4-4-4-1 distribution, then the opening should be 1 Heart.
Responder: A non-reverse change of suit rebid by opener is non-forcing, if the responder bids at the One Level, but is forcing if the responder has made a 2-over-1 response.
  Any change of suit rebid by the responder is forcing except over opener's 1 No Trump rebid.
Opener's Rebid: A non-reverse change of suit rebid by opener is non-forcing, if the responder bids at the One Level, but is forcing if the responder has made a 2-over-1 response.
  A reverse by opener is forcing for one round with 16+ points and at least 5-4 distribution and the first suit will be longer.

The following principles are major in the general principles of the Acol System. Much of this has to be learned by heart, but once it is memorized, then the auction proceeds with both partners acting as one. Even with the 5-Card American Standard we had to memorize certain guidelines and principles to show length and strength.

Fourth-Suit Forcing is generally forcing, except in the following bidding auction:

Opener   Responder
1   1
1   1
1. In this instance, a 1 No Trump rebid shows 15+ high card points and is generally forcing.
2. However, rebids by the responder at the two level are non-forcing over 2 / 2 / 2 by the opener.
3. Three-Level rebids are generally forcing.

Any possibly ambiguous bid by the opener or responder shows values or length in that suit. This is called fragmenting, rather than splintering, which means that the bid is indicating a stopper, rather than asking for a stopper.

Note: To fragment means to show a Stopper. To Splinter is asking for a Stopper, and this is very important to remember.

Over 3 of a Major, when there is a known fit in the Major, 3 No Trump is a natural bid, if Three of a Major is Non-Forcing. But it is a Trump Cue if Three of a Major is forcing.

Over 3 of a Minor, Three No Trump is always at least a suggestion to play.

A simple raise of responder's 2-over-1 is Invitational, that is Non-Forcing. A Jump raise to 4 of a Minor is Generally Forcing and suggests slam interest. Hands worth "3-5" Minor raise must find another bid.

The auction 1 Spade - 2 Hearts promises 5 cards in Hearts, but 2 of a Minor promises only a 4-card suit.

A new suit at the Four Level, after partner has shown strength, is a cuebid showing a hand too strong to raise partner's last bid suit directly.

The following bidding auctions should clarify this principle:

Auction Opener   Responder   Meaning
1. 1   1    
  3   4   Shows a strong Heart raise.
2. 1   1    
  3   4 /4   The rebid by responder is a cuebid, and Hearts is the agreed upon suit.
3. 1   2    
  2       Forcing bid for one round.
4. 1   1    
  3       This bid is invitational.
5. 1   2    
  3       This bid is game forcing.
6. 1   2    
  3       This bid is invitational.
7. 1   1    
  2   2 /3   Either of these rebids by responder is not encouraging, Non-Forcing.
8. 1   1    
  2   2   Indicates a 4-card Spade suit and is game forcing.
9. 1   1    
  2   2 NT   This bid is invitational.
10. 1   1    
  2   3   This bid is forcing for one round.
11. 1   1    
  2   3   This bid is game forcing, because opener has reversed.

In the bidding sequence:

Opener   Responder   Meaning
1   1    
2   3    
3   3   The last bid by the responder is an attempt at slam.
3 NT       This is a Trump Cue.

In the bidding sequence:

Opener   Responder   Meaning
1   3    
3 NT       This bid gives the responder a choice of the better contract.

These examples show the general principles of the auction using the Acol System. Many of them must simply be memorized. It is not surprising that many bridge players incorporate some/many of the guidelines used in the Acol System. We must remember that many intelligent minds went into devising new methods of bidding and thereby creating new Bidding Systems. Many of these methods and treatments and conventions have become intermixed with other Bidding Systems, and bridge players around the world use them without always realizing that they are an integral part of different Bidding Systems.



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.


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