This is Extended Roman Key Card Blackwood.
The four usual responses to a RKCB are exactly the same in ERKCB!
So here are the complete ERKCB responses:
- 5C 3 or 0 Key cards
- 5D 4 or 1 Key cards
- 5H 2 Key cards
- 5S 2¦4 Key cards & the Queen of trumps
- 5N 3 Key cards & the Queen of trumps
- 6C 2 Key cards & a useful void
- 6D 3 Key cards & a useful void
The last bid above must not be made if the agreed suit is Clubs for obvious reasons
In Beta ACOL this is not quite all!
In sequences where 3-suited hands are announced then when the 3-suited
hand announcer bids 4NT ERKCB he implies not 5 key cards but 7!
The 4 Aces and the 3 Kings outside his shortage! (6KC if shortage is
not exposed.) Cue-bidding is not
recommended with 3-suited hands as system sequences carry the bidding
into the 4th level, so ERKCB is more practical and to be preferred.
There is another sequence where 7 KC is used: following 1NT - 3X ....
if the opener asks 4NT there are 7 (as he is known to be
Yet another sequence is 1X-JY...and either X or Y is agreed as trump
suit. Then it is recommended that 6 Key cards are taken into account: 4
aces and the Kings of 'X' & 'Y'. when the owner of the trump suit bids 4NT ERKCB.
4NT bidder should possess 3 KC if asking about 7 KC & 2 KC if asking about 6 KC & 1KC if asking about 5 KC.