These notes are reproduced with the permission of Tony Haworth who has produced many bridge tuition pages at the Porthcawl Duplicate Bridge Club and here.
The notes have been modified to make them interactive. If you make an incorrect bid three times you will be able to see the correct bid.



-         Many slams depend upon one of the pair holding the trump king. With Ordinary Blackwood, this usually cannot be determined below the 6-level

-         The presence or absence of the trump queen can never be determined with Ordinary Blackwood.

Roman Key Card Blackwood, which evolved from the ace asking mechanisms of the great Italian teams of the 1960’s, is a refinement of ordinary Blackwood, and is based on aces, and the king of trumps. In addition, it enables the presence of the trump queen to be investigated for exploring the possibility of a grand slam.

Trump Agreement

It is of the utmost importance for the partnership to have agreed upon the trump suit before initiating Roman Key Card Blackwood (I would stress that partnerships do use different criteria – these are my personal recommendations). To overcome any ambiguity, apply the following rules in sequence (to assist in understanding the sequences. The eventual RKCB bidder is shown in pink).

  1. Any explicit suit agreed
    1♠ - 3 - 4NT is RKCB with spades as trumps
    1♣ - 1- 3 - 4NT is RKCB with diamonds as trumps
  2. Any implicit suit agreed
    1NT - 2 (Stayman) - 2 - 4NT is RKCB with hearts as trumps
    1 -  4 (splinter) – 4NT is RKCB with spades as trumps
    1 - 2NT (Jacoby) - 3 - 4NT is RKCB with hearts as trumps
    Since a 1NT or 2NT opener effectively has all the suits, I would also include any transfer suits following a 1NT or 2NT opening bid
    1NT - 2 (transfer to spades) – 2 - 4NT is RKCB with spades as trumps
    ….2NT - 3 (transfer to hearts) - 3 - 4NT is RKCB with hearts as trumps
  3. The last naturally bid or implied suit by the responder to 4NT (some players define this as the weaker hand, but this definition can become confusing)
    1♦ - 1 - 1 - 34NT is RKCB with hearts as trumps (the last naturally bid suit by responder).
    1 - 2 - 3 - 4 - 4NT is RKCB with hearts as trumps

For experienced players the above three rules should determine the trump suit in the majority of cases. However if due to lack of sophistication within the system, one further rule can be added

  1. The last naturally bid suit by the 4NT bidder
    2♣ - 2 - 2♥ - 3NT – 4NT is RKCB with hearts as trumps (responder hasn’t bid any suit naturally, so now reverts to the 4NT bidder who has bid hearts).

Note – the agreed trump suit doesn’t necessarily mean that this is the suit of the final contract. It can be used as a means of finding out about the king of that suit.


The responses include the king of trumps as a fifth ace, the preferred option being ‘1430’ (but some players do play ‘3014’) i.e.

5 - 1 or 4

5 - 0 or 3

5 - 2 (or 5) without the queen of trumps

5 - 2 (or 5) with the queen of trumps (or its equivalent – e.g. a 5-card suit implying a probable 10-card fit))

In these responses there can be ambiguities (e.g. 1 or 4), but either the previous bidding, or the 4NT bidders holding itself, usually makes it clear which is the most probable alternative.

(There is an advantage in playing different responses depending on whether a major or a minor is the agreed suit. With a major as the agreed suit play ‘1430’, but with a minor play ‘3014’. However only consider this with experience of the standard 1430 approach).

To progress to a slam, players should ensure that they have at least 4 out of the 5 key-cards (unless there are useful voids). Even then, a slam should be avoided if it can be determined that the partnership is missing one keycard and the trump Q.

If holding all five key-cards between the partnership, the 4NT bidder can then ask for kings by bidding 5NT. Remember that in response to this bid, ignore the king of trumps – it has already been accounted for in response to the 4NT bid (expert partnerships still use the bid if missing one key-card, primarily to assess whether 6NT would be a better contract at pairs).

Queen Ask (this can be adopted at a later stage)

Following 5 or 5, a bid of the next suit up is the queen-ask (usually used in investigating the possibility of a grand slam). (Special case – if hearts is the agreed trump suit, following a 5 bid (0 or 3), 5 is now the queen-ask opposite 3, but must be passed opposite 0).

The responses to the queen ask are: (by the trump queen we mean the queen or its equivalent (e.g. a 5-card suit – i.e. a 10+ card fit)):

Without trump queen, bid the trump suit at the lowest level.

With trump queen, bid 5NT with no other control (i.e. king).

With trump queen and another king, bid the suit containing the king.

If the trump suit is available at both the 5-level and the 6-level (usually the case with a major), then with the trump queen and no other king bid 5NT with something ‘extra’ (e.g. useful other queen(s)), whereas bid 6 of the trump suit with nothing ‘extra’

Void Showing (only when more experienced)

In the build-up to 4NT, players can usually show voids via cue-bids. However if this not the case, various modifications to the responses to 4NT can show voids. The method I prefer is to start the responses at 5NT when holding a useful void (judgement required – but a void in say opener’s first suit would probably not be useful). So 5NT shows 1 or 4; 6 shows 3 or 0 etc. (Care is needed with this approach if the agreed suit is a minor).

Asking For Other Kings

Various methods exist, but initially just use the standard approach, i.e. 5 = 1 king, etc. But remember there are only three kings available, since the trump king has been accounted for (or not) in response to the original 4NT bid. With experience other responses are better, my preferred choice being:

- bid six of the agreed trump suit with no other king;

- with one king, bid the suit of that king as long as it is lower ranking than the agreed trump suit (otherwise bid as if no other king);

- with two kings, bid the suit that doesn’t have the king

Examples (West the opening bidder):
(The bidding sequences take a simplistic approach up to the 4NT bid. Better sequences are available by way of cue bids etc. The examples concentrate solely on the use of RKCB).

(Note: Where a deal is to be bid you will first see the dealer's hand and after you have made a bid the next hand will be shown and you may bid that hand. When bidding has finished the complete deal will be shown.)

a) W S A H A87654 D K6 C AK87 E S K5 H KJ32 D QJ54 C 652 1H - 3H - 4NT (hearts) - 5C (1 ace or HK) - 6H
b) W S AJ1098 H Q D KQ3 C AK82 E S KQ75 H J1043 D A62 C 54 1S - 3S - 4NT (spades) - 5S (2 aces/SK and SQ) - 6S
c) W S AJ1098 H K D KQ3 C AK82 E S K7652 H AJ43 D 76 C 54 1S - 3S - 4NT (spades) - 5S (2 aces/SK and SQ) - 6S

In response, the 5-card spade suit is the equivalent to holding the SQ.

d) W S AQ7643 H AKQ7 D 8 C AK E S 1095 H 83 D KQ952 C Q74 2C - 2D - 2S - 3S - 4NT (spades) - 5D (0 or 3, obviously 0) - 5S

Two key-cards are missing - at best the slam depends on a finesse.

e) W S AQ87432 H 9 D AK106 C A E S 965 H AK854 D 52 C K54 1S - 2H - 3S - 4S - 4NT(spades) - 5C (1 or 4, obviously 1) - 6S

With one key-card missing the grand slam is not attempted.

f) W S A3 H AK97 D 83 C AK763 E S KQ954 H Q652 D AJ7 C Q7 1C - 1S - 2H - 4NT (hearts) - 5C (1 or 4, but obviously 4) - 6H

With Ordinary Blackwood the HK is concealed - West could be missing HK (having CJ, instead, making the slam less likely).

Queen Ask examples (g - j)

g) W S AKJ1043 H AQJ6 D 9 C AK E S Q52 H K87 D A1062 C 1073 2C - 2D (negative at this stage, but no other bid) - 2S - 3S - 4NT (spades) - 5C (1 ace or SK) - 5D (queen ask) - 5H (SQ and HK) - 7S

If responder had shown the DK in response, West would probably settle for 6S.

h) W S A5 H 10963 D A7 C AQ854 E S 6 H AK852 D KQ862 C K3 1C - 1H - 3H - 4NT (hearts) - 5D (0 or 3) - 5H (queen ask opposite three, sign-off opposite none) - 6H (confirms three key-cards, but denies the queen) - Pass
i) W S AK752 H J9764 D A7 C A E S 6 H AK852 D KQ862 C 53 1S - 2H - 4C (cue bid, agreeing hearts) - 4NT (hearts) - 5D (0 or 3) - 5H (queen ask opposite three, sign-off opposite none) - 5S (confirms three key-cards, and with the five-card suit, shows the equivalent of the queen, and also SK) - 7H
j) W S 8 H KQJ9654 D KQ82 C 5 E S A74 H A7 D A3 C A9762 4H - 4NT - 5C (1 or 4) - 5NT (for kings) - 7H

West knows that East must have all four aces to be asking for kings. If he held DSKQJx he would bid 7NT, but one diamond may need to be ruffed.

The following examples make use of my preferred methods - others are available.
k) W S A875 H AK62 D K64 C AK5 E S 4 H QJ43 D AQJ85 C 1087 2NT - 3C - 3H - 4NT (hearts) - 5C - 5NT - 6S - 7H

The 5C showing 1 or 4 (obviously 4), confirms all five keycards are held. East now asks for kings. West's response, being at a level higher than the agreed trump suit, now shows that he doesn't have SK and also has the other two kings. East can now be reasonably sure of all thirteen tricks.

l) W S AQJ854 H K8642 D A3 C E S K H AQJ9 D KQ9842 C 53 1S - 2D - 3H - 4NT (hearts) - 6C - 7H

Having agreed hearts, the 6C response shows 0 or 3 and a useful void (starting the sequences at 5NT, the 6S is equivalent to a 'normal' 5D showing 0 or 3). The only useful void is clubs, so the grand slam can be bid with confidence.