Source: Long ago a cue bid of the opponent’s suit in a competitive auction was used to show a stopper, inviting partner to bid notrump.  Today that style is referred to as an “Eastern Cuebid”as opposed to a “Western cuebid” which denies a stopper. This is an easy way to remember the Western Cuebid: A Cuebid at the 3-level asks partner to bid 3NT with a stopper in the opponents’ suit. First Example:
 West  East
K 7 J 10 3 A K 10 A J 10 9 4 A J 10 4 3 K 6 J 8 5 2 K 8
West North East South
1 1 1 2
3 Pass 3NT Pass
Pass Pass
West’s bid of 3 is the Western Cuebid.  Opener does not have spade support nor a heart stopper, but would like to play in 3NT if responder has a heart stopper.  East has a heart honor and bids 3NT to show it. Second Example:
 West  East
J 7 6 2 A K 10 9 7 2 K J 4 A K 8 2 10 8 5 J 8 A 10 9 8
West North East South
1 Pass 1 2
3 Pass 3 Pass
4 Pass Pass Pass
3by East is the Western Cuebid.  3NT would be a good contract if opener can control the heart suit.  Note that opener’s rebid of 4denies both a heart stopper and also denies support for responder’s suit. These two examples show you that the Western Cuebid can be used by either the opener or the responder. Here are some generally accepted agreements and refinements you should consider…

Western Cuebids Are Only Used at the 3-Level

 West  East
A K Q 10 9 6 3 A K K J 10 7 8 5 3 A J 8 Q J 9 7 2 9 2
West North East South
1 1 2 2
3is not a Western Cuebid because hearts have already been agreed as trumps.  In this particular auction the cuebid shows first round control of spades and an interest in slam.

Other Agreements

Opponents Bid Two Suits When the opponents have bid two suits, a cue bid is not the Western Cuebid, but instead shows a stopper in the bid suit.  Partner is asked to bid 3NT with a stopper in the other suit. After a Takeout Double After partner makes a takeout double of a minor suit, a cuebid at the 4-level shows at least 4-4 in the majors and asks the doubler to choose the best one. The Jump Cuebid You will need to discuss this with your partner and reach an agreement, as there is no “standard” rule for it, but here are threee possible methods:
  • Always   Anytime you cuebid at the 3-level it is the Western Cuebid
  • Minor Opening   A jump cuebid of an opponent’s suit after partner has opened a minor is the Western Cuebid
  • Major Opening   A jump cueid of an opponent’s suit after partner has opened a major is a Splinter bid showing a singleton or void and good support for opener’s suit with some slam interest – not the Western Cuebid