The Acol System is used by many bridge players around the world, and is employed mainly in British tournament play. It is a different system than the American 5-Card System, which employs the agreement that a Major suit opening bid demands at least a 5-card suit.

The Acol System was the brain-child of various bridge players, among whom were Mr. Maurice Harrison-Gray, Mr. Iain Macleod, Mr. J. C. H. Marx, Mr. Terence Reese and Mr. S. J. Simon. The history of the Acol System is rather unique in that it was first employed in 1934 in a relatively small North London Bridge Club located on Acol Street, and hence the name. The bridge players mentioned above relied heavily on the early writings about the Game of Bridge written by Mr. Ely Culbertson.

If the visiting bridge player wishes to improve his understanding of this particular bidding system, then the purchase is strongly recommend of the following publication authored by Mr. Patrick Jourdain in the year 2005. which is available at Amazon or Baron Barclay: ISBN-10: 0713489715.


Following are several basic guidelines, conventional methods, and approaches, which are employed in the basic Acol System. The list is definitely incomplete, but the idea is to understand the basics first, and that is the sole purpose and intention of this web presentation.

Since one of the cornerstones of the Acol bidding system is the flexibility of the opening of 1 No Trump the player should always pay particular attention to the approach agreed upon by the opponents. The range of the values of the No Trump bid may vary considerably depending on the state of vulnerability and sometimes even on the opening seat.

The weak No Trump is applied when the players are not vulnerable. The original No Trump range was 13-15 high card points, but this range has been reduced to 12-14 high card points over the years. As a precaution always make a quick review of the convention chart to ascertain the 1 No Trump range(s).
The strong No Trump is applied when the players are vulnerable. The original No Trump range was 16-18 high card points, but this range has also been reduced to 15-17 high card points. As a precaution always make a quick review of the convention chart to ascertain the 1 No Trump range(s).
Some bridge partnerships apply the weak No Trump and the strong No Trump at any vulnerability. As a precaution always make a quick review of the convention chart to ascertain the 1 No Trump range(s).
Limit Raises and No Trump Responses
Both limit raises and No Trump responses are generally not game-forcing in the basic form of the Acol bidding system. After an opening bid of 1, a response of 2 No Trump or 3 is encouraging, but not game-forcing. Each response shows about 11 high card points.
Jump rebids are not forcing unless they are in a new suit.
If the opening is one of a suit, then the required strength and Quick Trick ability can be slightly lower than in American methods, especially if the opener holds a 6-card suit.
Two-Over-One responses were originally made even on weak hands with about 8 points, but are presently played using the strength required for traditional American Standard, which is approximately 10 high card points. However, some Acol players feel that this response is forcing to at least 2 No Trump.
Fourth Suit Forcing bids are used conventionally by most Acol bridge players.
A strong, artificial 2 Clubs opening bid means an artificial strong opening and is forcing to 2 No Trump.
An Acol Two-Bid is forcing for one round.
Gambling 3 No Trump equals a long and strong Minor suit with at least two other suits protected with a stopper.
A 4 No Trump Opening is a bid asking for specific Aces. The partner may not have passed previously when this bid is applied.

Optional Agreements of the Partnership

Acol Direct King Convention
Baron Slam Try
Culbertson 4-5 No Trump
Gerber Convention
Grand Slam Force
Interest-Showing Bids
Kock-Werner Redouble
Responsive Double
Roman Blackwood
Roman Two Diamonds
Short-Suit Game Try
Stayman Convention
Strong No Trump After Passing
Trial Bid
Unusual No Trump
Void-Showing Bids

All of these optional agreements can be found on this site by returning to the Conventions web page and performing a search with the provided Google site search feature.

Also, any bridge player interested in the Acol bidding system has a large selection of publications, which deal solely with this approach.



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.