Roman Key Card Blackwood (RKCB 1430)
Roman Key Card Blackwood upgrades plain Blackwood by counting five key cards — the four aces plus the king of trumps — and then locating the trump queen. It is the slam tool serious partnerships rely on.
Why Count Five Cards
Standard Blackwood counts aces and nothing else — yet most suit slams turn on two other cards: the king and queen of trumps. Roman Key Card Blackwood folds them in. It treats the trump king as a fifth ace (a “key card”) and adds a way to ask for the trump queen.
The result is one bid that answers the questions that actually decide the hand: are we missing two key cards, and do we hold the trump queen? See the wider context in our slam bidding guide.
The 1430 Responses to 4NT
The most popular version is “1430,” named for the meaning of its first two steps. Each reply shows a number of the five key cards.
Key-card responses (1430)
The Trump-Queen Ask
When partner’s reply did not already tell you about the trump queen (the 5♣ and 5♦ steps), you can ask for it directly.
After a 5♣ or 5♦ answer, bid the cheapest non-trump suit. That is the queen ask. Partner returns to the trump suit at the lowest level without the queen, or bids something else — usually showing a side king — to promise the queen. Knowing whether the trump suit is solid is often the difference between a safe small slam and a hopeless one.
A Worked Example — RKCB in Action
Hearts are agreed after 1♥–3♥, and you, the opener, hold a hand worth driving toward slam:
Counting key cards, you hold three: the trump king (♥K), the ♠A and the ♦A. You also hold the trump queen yourself, so the queen is not a worry. You bid 4NT.
Partner replies 5♣ — 1 or 4 key cards. It cannot be 4 (you hold three of the five), so it is one. That makes four of five key cards present, with only one missing, so you bid 6♥. Because you own the trump queen, the suit is rock-solid and the slam is excellent.
Beyond the Basics
♠ The 5NT king-ask
- Shows all key cards are present
- Asks partner to show specific kings
- Aims the auction at a grand slam
✗ Watch out for
- Voids — use the special void responses you have agreed
- Forgetting which suit is trumps — you must count the same king
- Confusing 1430 with 3014 mid-auction
Common RKCB Mistakes to Avoid
- Counting the wrong king. Only the king of the agreed trump suit is a key card. Side-suit kings do not count toward the five.
- Mixing 1430 and 3014. Pick one with your partner and never switch in the middle of an auction.
- Forgetting the queen ask. After a 5♣/5♦ reply, use the cheapest non-trump bid to check the trump queen before committing to slam.
- Bidding RKCB with no agreed trump suit. Without a fit, neither player knows which king to count — agree the suit first.
Key Takeaways
- Five key cards = four aces plus the king of trumps.
- 1430 replies: 5♣ (1/4), 5♦ (0/3), 5♥ (2/5 no Q), 5♠ (2/5 with Q).
- The cheapest non-trump bid after 5♣/5♦ asks for the trump queen.
- 5NT confirms all key cards and asks for kings — a grand-slam try.
- Always agree the trump suit and your 1430 vs 3014 choice first.
Related Guides
Frequently Asked Questions
The five key cards are the four aces plus the king of the agreed trump suit. Treating the trump king as an ace is what makes RKCB so accurate for suit slams.
They swap the meaning of the first two responses. Playing 1430, 5 clubs shows 1 or 4 key cards and 5 diamonds shows 0 or 3; playing 3014 it is the reverse. Pick one and write it on your card.
After a 5 clubs or 5 diamonds reply, bid the cheapest suit that is not trumps. Partner signs off in the trump suit without the queen, or bids beyond it to promise the queen.
For suit slams, yes. The trump king and queen decide most slams, and RKCB locates them in one ask. Keep plain Blackwood only until keycards feel comfortable.
A follow-up of 5NT confirms the partnership holds all the key cards and asks partner to show specific kings, with a grand slam in mind.
RKCB needs an agreed trump suit so both players count the same king. If the auction is ambiguous, the last genuinely supported suit is trumps — agree a default to avoid a counting disaster.