Roman Key Card Blackwood

This convention is becoming increasingly popular at the DATEN club. It is still not played by the majority of members who use 'ordinary' Blackwood. Below is one popular version for those who might like to give it a try.


When the trump suit is agreed, we use the 4 aces and the king of trumps as the ‘key’ cards, effectively there are 5 'aces'. When the trump suit is not agreed, the ‘key’ suit is the last suit bid.

The responses to 4NT are as follows:

5 clubs = 0 or 3 key cards
5 diamonds = 1 or 4 key cards
5 hearts = 2 key cards
5 spades = 2 key cards + Queen of key suit

If the 4NT bidder then wants to enquire about kings, then 5NT asks. The responses are: -

6 clubs = 0 or 3 kings
6 diamonds = 1 king
6 hearts = 2 kings


There are only 3 kings, as the king of trumps has already been accounted for.

When the response to 4NT is 5 clubs or 5 diamonds response, the absence or presence of the queen of trumps is not known. we can find out about the queen by bidding 5 of the next suit up as an asking bid (not the trump suit which is a sign-off).

Let’s suppose that spades are trumps. The bid 4NT has received a 5 diamond (1 keycard) response. If asker then wants to ask about the trump Q, the bid is 5 hearts. The responses are as follows: -

5 spades = denies having the trump queen
5NT = i have got the trump queen.