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Roman Key Card Blackwood

Roman Key Card Blackwood (RKCB) is a slam bidding convention in bridge. 4NT asks for 'keycards' which are the 4 aces plus the King of trumps. Subsequent bidding can sometimes be used to ask if partner holds the Queen of trumps

Responding to Roman Key Card Blackwood

5♣0 or 3 key cards
51 or 4 key cards
52 key cards but no trump queen
5♠2 key cards with the trump queen
5NT5 key cards

The 5NT response is virtually never used as you should not be asking for key cards if you do not have any in your own hand.

The main purpose of using regular Blackwood (4NT asking for aces followed possibly by 5NT asking for kings) is to ensure that your partnership has at least three aces when bidding to the 6 level or indeed has all four aces should you attempt a grand-slam.

However, when you are to play in a suit contract, the presence or absence of the trump king and trump queen are almost as important as the four aces themselves. Take the following two hands:

Roman Key Card Blackwood in Bridge

5♠ showed three aces. The partnership has 32 high card points but terrible trumps. The slam must fail.

The solution is to play Roman Key Card Blackwood where the trump king carries the same importance as the four aces.

Subsequent Bidding

The bid of the trump suit at the 5 level by the 4NT asker is always a sign-off. The responder must pass (though see an exception in question 2 below).

After the 5♣ and 5 responses above, the 4NT asker can then find out about the presence/absence of the trump queen by bidding the next suit up which is not the trump suit.

Roman Key Card Blackwood in Bridge

This asks two questions:

  1. "Partner, do you have the trump queen?"
  2. "If you do, please tell me how many kings you have, but not including the trump king."

The responses are in steps: the higher your response, the better is the hand. Spades are trumps in the example shown so the responses would be as follows:

Responding to RKCB Queen ask:
5♠no ♠Q
5T♠Q but none of the 3 non- trump kings
6♣♠Q and 1 of the 3 non- trump kings
6♠Q and 2 of the 3 non-trump kings
6♠Q and all 3 non-trump kings

Note the first and more important question revolves around the trump queen. If it is not held, do not tell partner the number of kings.

What if the 4NT asker holds the trump queen, or gets an initial 5 or 5♠ response to 4NT and wants to ask for kings? The bid the asker makes is 5NT.

Responding to RKCB King ask:
6♣0 of the 3 non- trump kings
61 of the 3 non-trump kings
62 of the 3 non-trump kings
6♠all 3 non-trump kings

(The trump queen's position is no longer part of the question.)

Examples of Roman Key Card Blackwood

Roman Key Card Blackwood in Bridge

The same bidding up to 4NT. East's 5♣ shows 0 or 3 key cards. West knows one key card is missing but is still prepared to bid to the 6 level if East has the Q.

This is the hand from the top of the page. 5 asks the 2 questions and since East does not hold this card, they bid 5. West passes and this time the impossible slam is avoided.

Roman Key Card Blackwood in Bridge

5♠ shows 2 of the 5 key cards and the Q. The excellent 26 high card point slam is bid in comfort using RKCB.

Common Questions

Why do we keep referring to "non-trump kings"?

The reason is that the presence or absence of the trump king has been shown already in the response to 4NT. We do not need to show or deny it again.

How do I know whether my partner is showing 0 or 3 key-cards, or indeed 1 or 4?

The answer is often obvious from your own hand. If you hold 2 key cards and your partner shows 1 or 4, you know it must be 1 as there are only 5 key cards. Sometimes the bidding makes it obvious. If your partner had shown 20-22 high card points in the bidding, and then shows 0 or 3 key cards, you know it must be 3.

Occasionally, though, you cannot be sure. In those cases, sign off at the 5 level and if your partner has the higher number (3 or 4), they should raise to the 6 level. Remember, the asker should always have at least 1 key card.

Can one use RKCB in no-trumps, i.e. with no suit agreement?

No, you cannot as there is no trump king or queen. With no suit agreement, and the previous bid being 1NT, 2NT or 3NT, use 4♣ Gerber to check for aces with your normal responses.

How do I know what the trump suit is?

Trumps are normally agreed first, as in our two examples above. However, occasionally, it is the last bid suit before the 4NT bid:

Roman Key Card Blackwood in Bridge

Clubs will in this case be the agreed trump suit.

Can I use splinters and cue bids with RKCB?

Sure you can! Splinters and cue bids are a great help in hand evaluation and work well with RKCB.

Roman Key Card Blackwood 1430

Roman Key Card Blackwood 1430 is a variation of Roman Key Card Blackwood with a slight change in the meaning of the responses.

The normal responses to Roman Key Card Blackwood
  • 5♣ = 0 or 3 keycards
  • 5 = 1 or 4 keycards
  • 5 = 2 keycards without the Queen of trumps
  • 5♠ = 2 keycards with the Queen of trumps

With Roman Key Card Blackwood 1430, the responses are slightly different.

Responses to Roman Key Card Blackwood 1430
  • 5♣ = 1 or 4 keycards
  • 5 = 0 or 3 keycards
  • 5 = 2 keycards without the Queen of trumps
  • 5♠ = 2 keycards with the Queen of trumps