[thepossum]

Do people have different agreements for the King ask after RKCB
I always find it rather limiting the way you only get information on one King
Even a standard king ask would have given all the required information for 7NT

I tried the splinter and cue approach but North started Blackwood and stopped in 6D

[pescetom]

 thepossum, on 2026-January-12, 17:39, said:

Do people have different agreements for the King ask after RKCB
I always find it rather limiting the way you only get information on one King
Even a standard king ask would have given all the required information for 7NT

You can still get information on any other Kings, although there is no clear standard (just as there is no clear standard about what to do with a King in a higher strain than trumps when you use 5NT as the ask in a red suit).
With my partners (when we do RKCB, which is rarely) I play that 6NT shows all three Kings, return to trumps denies any King that could be shown at a lower level, a suit shows a Specific King. After a Specific King is shown, a cue of the suit above specific King asks for a second King: now a return to trumps denies a second King, 6NT shows the second King in suit that was cued, the third suit shows the second King in that suit.
It's easier to play than to explain As with all RKCB (including your obsolete standard number of Kings ask) it only works perfectly when trumps are spades or you play a Kickback.

[Huibertus]

thepossum, on 2026-January-12, 17:39, said:

Do people have different agreements for the King ask after RKCB
I always find it rather limiting the way you only get information on one King
Even a standard king ask would have given all the required information for 7NT

I tried the splinter and cue approach but North started Blackwood and stopped in 6D

The solution is to bid the King you hold when you have 1 king, and to bid the king you DON'T hold when you have 2 Kings. The partner asking for Kings should normally be able to figure this one out (having a King himself or calculating 1 king or 2 kings is outside the promised HCP range) and then has the full picture.

I.e assume ♠ = trumps, you are looking at ♦ K, asked Kings and partner responds:

6 ♣ , promising ♣ King or ♦+♥ King, must be ♣ King only as you hold ♦ king yourself.
6 ♦ , promising ♦ King or ♣+♥ King, must be ♣+♥ King as you hold ♦ king yourself.
6 ♥ , promising ♥ King or ♣+♦ King, must be ♥ King only as you hold ♦ king yourself.

Or suppose you are NOT looking at a king, but know partner's range. I.e. Partner opened a weak (12-14) 1NT, you hold long ♠ asked keycards, partner held two keycards and trump Queen, you are asking Kings, partner responds with any of the 1/2 king options. He must have the one king option, otherwise he was too strong for opening 1NT.

[pescetom]

Huibertus, on 2026-January-14, 04:31, said:

The solution is to bid the King you hold when you have 1 king, and to bid the king you DON'T hold when you have 2 Kings. The partner asking for Kings should normally be able to figure this one out (having a King himself or calculating 1 king or 2 kings is outside the promised HCP range) and then has the full picture.

I.e assume ♠ = trumps, you are looking at ♦ K, asked Kings and partner responds:

6 ♣ , promising ♣ King or ♦+♥ King, must be ♣ King only as you hold ♦ king yourself.
6 ♦ , promising ♦ King or ♣+♥ King, must be ♣+♥ King as you hold ♦ king yourself.
6 ♥ , promising ♥ King or ♣+♦ King, must be ♥ King only as you hold ♦ king yourself.

It's elegant, but unless I missed something it seems less flexible than my solution of cueing the suit above, in particular following a Queen ask in a red suit.
Say it goes:
1♦ - 2♣ (GF)
3♦ - 4♦ (SI)
4N (RKCB) - 5♦ (0/3 keyc)
5H (♦Q ask) - ?

How do you respond holding the ♦Q and various combinations of lateral Kings?
With my solution you can still show ♠K, ♣K, ♠K + ♣K, ♠K + ♣K + ♥K.

[Huibertus]

pescetom, on 2026-January-14, 16:04, said:

It's elegant, but unless I missed something it seems less flexible than my solution of cueing the suit above, in particular following a Queen ask in a red suit.
Say it goes:
1♦ - 2♣ (GF)
3♦ - 4♦ (SI)
4N (RKCB) - 5♦ (0/3 keyc)
5H (♦Q ask) - ?

How do you respond holding the ♦Q and various combinations of lateral Kings?
With my solution you can still show ♠K, ♣K, ♠K + ♣K, ♠K + ♣K + ♥K.

6♦ - No queen (that should end the bidding at the 6 level, otherwise the Q ask should not have been the bid).
5♠ - ♠K or ♣King + ♥ King
5NT (the missing suit) - ♥ King or ♣ + ♠ King
6♣ - ♣ King or ♥ King + ♠ King.

You DO have a point though. Which is why if the partnership is able to work out a good set of agreements as to when it applies and when it doesn't, and is able to remember them Kickback RCKB is preferable.