So blackwood is a method of finding how many aces the partnership has….but using RKCB you can find out the aces, the king of trumps and the queen of trumps…all useful cards for a slam. You can also go on to find out about other kings.

  • 3 – singleton clubs


So this assumes you’ve agreed a suit fit…let’s say the bidding has gone…


In this example 2 diamonds was a game force (some people play this as a weak 2 in diamonds). Here 4NT would be RKCB agreeing spades.

The first bid looks at the four aces, the king of trumps and the queen of trumps. So it counts the King of trumps as the 5th Ace…clearly it’s an important card when looking for a slam.

The responses to 4NT are:-

  • 5♣ = 1 or 4 This shows one or four aces
  • 5 = 0 or 3 This shows none or three aces
  • 5 = 2 or 5 This shows two or 5 aces
  • 5♠ = 2+Q This shows two aces plus the queen of trumps

This style of RKCB is known as 1430 and is commonly accepted to be the best way of playing it….


  • 5♣ = 0 / 3 This shows none or three aces
  • 5 = 1 / 4 This shows one or four aces

This style of RKCB is known as 3014 and is now frowned upon by some Expert players!


How do you ask for the trump queen?

Whatever the response is…such as 5 clubs or 5 diamonds, then the next SUIT bid up asks for the trump Queen. Note if you had agreed hearts and the response was 5 diamonds…you would need to bid the next bid up from the trump suit…i.e. 5 spades. Or if you know that 5 diamonds equals 3 controls then you can use 5 hearts as a queen ask….partner shouldn’t pass if he gives a positive response!

To deny the trump queen you can bid the trump suit at the lowest level. If you have the trump queen you can:

  • Jump to slam with no other useful cards in your hand.
  • Bid a suit with a king in or cue bid to show the two other kings (see later)
  • Bid 5NT to show zero kings but a useful queen or queens.

So in this case 5 clubs shows 1 or 4 keycards. 5 diamonds* asks for the Queen of spades. 5 spades would deny the trump queen.

If instead of 5 spades being bid and 5 hearts was bid instead this would show the King of hearts and the Queen of trumps.


Here the 6 clubs* would show the trump queen plus the King of clubs.

So what about asking for kings?


Here the 5NT asks for kings….you can play this several ways…straightforward asking for the number of kings or cue bidding the kings….

Asking for kings the replies would mean:

  • 6♣ = 0 kings
  • 6 = 1 King
  • 6 = 2 Kings
  • 6♠ = 3 Kings

Another popular method….one which I prefer and recommend is to cue bid the kings:

  • 6♣ = The king of clubs, or the two none touching kings, or two other kings.
  • 6 = The king of diamonds, or the two none touching kings, or two other kings.
  • 6 = The king of hearts, or the two none touching kings, or two other kings.
  • 6♠ = The king of spades, or the two none touching kings, or two other kings.

Again this is down to partnership agreement whether you can bid the two kings you don’t have! Also make sure if it shows 2 none touching kings or the other 2 missing kings.

This is also known as paradox kings when you make a bid in a suit where you don’t actually have the king in that suit…but it shows the other two kings….the paradox.

What Do I Do With A Void?

A common response to 4NT is:

  • 5NT = 0 / 2 / 4 with a useful void
  • 6♣// = 1 /3 with a useful void in that suit.
  • 6 trump suit = 1 / 3 with a void in a suit above the trump suit

A useful void would be a suit that partner hasn’t bid….very often it will be the splinter bid.

What happens when the opposition interfere over 4NT?

There is a full explanation on what happens if the opposition double or bid against you here. It’s generally called DOPI-ROPI !

Let’s look at a sequence

♠ AJ10987♠ KQ4
87 AK32
♣ AKQ♣ 983

So with this hand the bidding would go:


Bidding explanations….

  • 2♣ – Big hand
  • 2 – Relay
  • 2♠ – 8 Playing Tricks with spades as trumps
  • 3 – Slam try in spades
  • 4♣ – Cue Bid
  • 4 – Cue Bid denies the ace of diamonds
  • 4NT – RKCB 4130 responses
  • 5♠ – 2 out of the 5 aces + Queen of spades
  • 5NT – Asks to cue bid kings
  • 6♣ – Shows the king of clubs or the other two kings….therefore must be two red kings
  • 7NT – I can count to 13!