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Roman Key Card Blackwood (Key Card, RKC, RKCB, 0314, 1430) is a variation of the Blackwood convention. It is used when the partnership has agreed to a trump suit and is interested in slam. A 4NT bid asks partner how many "key cards" he holds. A key card is any ace or the trump suit king.

There are two versions of RKC: 0314 and 1430 ("Fourteen-Thirty"), which refer to the step responses below.

Responses to 4NT

Playing 0314

Responder's Bids Meaning
5Shows 0 or 3 key cards.
5 Shows 1 or 4 key cards.
5 Shows 2 or 5 key cards without the queen of trumps.
5 Shows 2 or 5 key cards with the queen of trumps.

Playing 1430

Responder's Bids Meaning
5 Shows 1 or 4 key cards.
5 Shows 0 or 3 key cards.
5 Shows 2 or 5 key cards without the queen of trumps.
5 Shows 2 or 5 key cards with the queen of trumps.

The 4NT bidder can usually (!) determine if responder has 0/3, 1/4, or 2/5 key cards.

Void-showing responses

If responder has a void, she can make one of the following bids to describe her hand.

Responder's Bids Meaning
5NT Shows an even # of key cards and a void somewhere.
6 Shows an odd # of key cards and:
  • A club void if clubs aren't trumps, or
  • A void in any other suit if clubs are trumps
6 Shows an odd # of key cards and:
  • A diamond void if hearts or spades are trumps, or
  • A void in hearts or spades, if diamonds are trumps
6 Shows an odd # of key cards and:
  • A heart void if spades are trumps, or
  • A spade void if hearts are trumps

Asking for Kings (5NT)

A 5NT rebid asks partner for kings. It is a grand slam try, and should only be bid if the partnership holds all 5 key cards and the queen of trumps.

There are two ways to play 5NT:

  1. To ask partner to bid his cheapest (non-trump) king.

  2. To ask partner how many kings he holds (standard Blackwood responses):
      6 shows 0 kings.
      6 shows 1 king.
      6 shows 2 kings.
      6 shows 3 kings.

An example auction playing RKCB with the 5NT "cheapest" king-ask:


4NT (1)
5NT (3)
6 (5)

5 (2)
6 (4)

  1. RKCB for hearts.
  2. 2 key cards without the Q.
  3. Asking for partner's cheapest king.
  4. Showing the K.
  5. Signing off because of the missing K.

Asking for the Trump Queen

Sometimes the 4NT bidder wants to know the location of the trump queen, but hears a 5 or 5 reply. These responses don't indicate whether responder holds the queen of trumps. So, the 4NT bidder can bid the cheapest non-trump suit to ask this question. The responses to the queen-ask are as follows.

Responses to the Queen Ask Meaning
Bidding the trump suit   No trump queen
5NT The trump queen without any side-suit kings
Bidding any non-trump suit   The trump queen AND the king of that suit

An example auction playing RKCB 1430 with a queen-ask:


4NT (1)
5 (3)

5 (2)
5 (4)

  1. RKCB for spades.
  2. 1 key card.
  3. Asking for the Q.
  4. Denies the Q.

Why You Should Play 1430 vs. 0314

American expert Marty Bergen says that he asked 60 top pairs which Blackwood variant they use. 8 use plain Blackwood, 8 use RKC 0314, and an overwhelming 44 use RKC 1430. 1

Why is this? Eddie Kantar, author of "Roman Keycard Blackwood: The Final Word", theorizes that RKCB is usually used when a "strong" hand is interested in slam, and wants to ask the "weak" hand for key cards. As a corollary:

"One of the beauties of using Roman Key Card Blackwood instead of regular Blackwood is that it allows the 4NT bidder to ask partner whether he holds the queen of the agreed suit, as well as for other goodies. (Ed. note: See 'Asking for the Trump Queen', above.) To do this economically the asker needs room. The optimal response to 4NT, therefore, is 5 (as opposed to 5) allowing a follow-up bid of 5 to become the queen-ask.

"Playing 0314, a 5 response shows zero or three. '3' is a highly unlikely response when the stronger hand asks the weaker hand, so the 5response figures to show "0".

"After a zero response the asker usually signs off. The end result is that a 5 response seldom leads to any further asks.

"Playing 1430 the 5 response shows one or four. It doesn't take a rocket scientist to work out that it shows '1'. Now if the asker wishes to ask for the queen, 5 is available. This lower step is especially important when hearts is the agreed suit. Now the queen-ask can be made beneath the five level of the agreed suit.

"Playing 0314, the '1' response is 5, preempting the asker out of a lower-level queen-ask if hearts is the agreed suit. Clearly 1430 works best when the strong hand asks the weak hand."2

RKCB In Competition

See ROPI when the opponents double 4NT. Redouble shows 0, 3 or 5 keycards while Pass shows 1 or 4 keycards.

There are a number of ways to show key cards if 4NT is overcalled. One way is called DOPI, which stands for "Double = 0 (or 3 or 5) key cards, Pass = 1 (or 4)." The cheapest available bid shows two key cards, the second-cheapest bid shows three key cards, and the third- cheapest bid shows four.

Another method of showing key cards is DEPO, which stands for "Double = Even number of key cards, Pass = Odd number of key cards."

Other Considerations

  • It is important to agree with partner when RKC is on, and when it is off. Sometimes one player wants to just ask his partner how many real aces he holds, and this can cause a lot of confusion at a precariously high bidding level.

  • In short, RKCB can get very complicated. That is why Kantar was able to write a 244-page book about it. It requires a healthy amount of partnership discussion.


Roman Key Card Blackwood was initially based on Roman Blackwood, a Blackwood variant that was used by the famous Italian Blue Team in the 1960s. American expert Eddie Kantar is credited with popularizing the "key card" nature of the convention thereafter.

External Articles


1 Bergen, Marty (2008). Slam Bidding Made Easier. Note: Mention "BRIDGEBUM" when buying this book directly from Marty to get 2 softcover books free.

2 Kantar, Eddie (2003). "A Key Question." ACBL Bulletin, January 2003.

See also

  • Baby Blackwood
    A conventional 3NT ace-asking bid after a major-suit fit is found.

  • Blackwood
    The original 4NT convention invented by Easley Blackwood to ask for aces.

  • Gerber
    The convention for asking for aces in no-trumps slam auctions.

  • Grand Slam Force
    A 5NT bid as a conventional grand slam try.

  • Roman Blackwood
    The Italian variation of Blackwood upon which RKCB is based. The responses to 4NT include the rank and colors of the four aces.

  • DEPO
    A conventional Blackwood or Gerber response after interference: Double = Even, Pass = Odd.

  • DOPI
    A conventional Blackwood or Gerber response after interference: Double = 0, Pass = 1.

  • ROPI
    A conventional Blackwood or Gerber response when the opponents double: Redouble = 0, Pass = 1.