Roman Key Card Blackwood 1430
With no agreed suit, standard Blackwood is used.
5 = 0 or 3 keys counting the trump King
If responder bids 5 or 5, he is not able to show the trump Queen.
After 4N-P-5-P. Asker bids 5 if Hearts are not trumps; otherwise, he bids 5.
Bid 5N with the trump Queen and no side-suit Kings.
Bid a non-trump suit with the trump Queen AND the King of the suit bid.
5 = 2 or 5 keys WITHOUT the trump Queen
5 = 2 or 5 keys AND the trump Queen
5N = 0, 2, or 4 keys with an unnamed void
6// = 1 or 3 keys and a void in the suit bid excluding the trump suit.
bidding 6 lets your partner know that you have a void in Hearts or Spades without going past 6.
(If the void were in Clubs, you would have bid 6.)
If Hearts are trumps, you can bid 6 or 6 to show 1 or 3 keys and a void in the suit bid.
Since you will not bid 6 if Hearts are trumps, a bid of 6 indicates 1 or 3 keys and a
void in Spades, the only suit left, without your having to bid past 6.
5N Asks for number of Kings, excluding the trump King, and implies having all keys.
6 = 1 King
6 = 2 Kings
6S = 3 Kings