This defense method against a No Trump opening by the opponents was devised by Mr. Peter James Wallis of Brisbane, Australia. The visitor should, however, review the information included below, which supports Mr. Brian G.H. Wallis of England as the first person to devise the concept.

Note: Any substantiating information from the bridge community would be greatly appreciated as well as any additional and relevant information, including photographic material as well as confirming sources.

Note: The guidelines are outlined below. The overcalls generally promise either a two-suited holding or the overcall is natural.

Important Information

Note: Some partnerships have agreed that the distribution of the holding, when overcalling could / may be reduced to 4-4 in both Major suits regardless of the state of vulnerability, otherwise the distribution is generally 5-4, 4-5, or 5-5 depending on the state of vulnerability. This is entirely a partnership agreement in all employed variations of the concept.

Source: Bridge: Classic and Modern Conventions, authored by Mr. Dan Dimitrescu and Mr. Nicu Kantar, Edited by Mr. Magnus Lindkvist, published 2001, Publisher: Example Product Manufacturer, page: 1579, ISBN-10: 9163110997 / ISBN-13: 978-9163110993.

Note: According to an email message from Mr. Richard Fleet, dated September 27, 2011, this concept was developed by another bridge player. The email message is quoted below without change:

This convention was actually invented by an Englishman, Brian G. H. Wallis, who attended both the same school (Manchester GS) and the same university (Cambridge) as I did. He invented the convention around 1973 simply because he wanted to experience the EBU licensing procedure! A number of Cambridge players took up the convention and played it successfully, including the eminent partnership of John Armstrong and Graham Kirby.

Note: This information cannot be independently verified nor can any such reference be found to substantiate that this is the original concept of Mr. Brian G. H. Wallis. Any assistance regarding this information would be greatly appreciated.

Important Information

On February 12, 2017, Mr. David (Dave) Harrison of the University of Cambridge enclosed in his email message to this website the following information, for which we are very grateful:

The original Wallis convention was devised by Brian Wallis, probably when he was a Cambridge University student in the early to mid 1970s. The variation known as Modified Wallis was devised by the English international Richard Fleet, very soon after the original version came into being.

The website of Mr. David (Dave) Harrison can be found at this source.

No Trump Overcall Outline

The overcalls, following a No Trump opening by the opponents, and their meanings are shown below.

2 : This is an artificial bid showing a Major-Minor two-suited holding. Either and or , or and or .
  The partner of the overcaller, the advancer, bids 2 NT, which is an artificial relay requesting additional information. As the reader can see from the other overcalls, this is the cheapest bid, which is artificial. New suits are for correction and only to play if the bid suit is one of the suits of the intervenor.
2 : Promises a two-suited holding in both Major suits.
  The advancer employs the following bids to invite and/or as natural or preemptive bids. These bids are by partnership agreement, but are strongly recommended by Mr. Peter James Wallis. (Note: the jump raise in both Major suits may be changed to the two level to show weakness, whereas a jump signifies a possible game contract, or the jump is purely preemptive per partnership agreement.)
3 : Artificial and also an invitational raise in Hearts.
3 : Artificial and also an invitational raise in Spades.
3 : Generally natural, but can be also preemptive by partnership agreement.
3 : Generally natural, but can be also preemptive by partnership agreement.
2 : Promises generally a 6-card plus Heart suit. Natural.
2 : Promises generally a 6-card plus Spade suit. Natural.
2 NT: Promises a Minor suit two-suited holding. The advancer relays to 3 and intervenor passes if Clubs is the suit. Otherwise the intervenor corrects to Diamonds.



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.