Practice on Cuebids
Practice slam hands where key cards, controls, voids, and final contract judgment matter.
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Systems
Last updated
2026-08-01
What is Exclusion Blackwood?
Exclusion Blackwood is an ace or keycard ask used when a trump suit is agreed and the asker has a void. The bid tells partner to ignore the ace of that suit because it is not useful opposite the void.
Plain Exclusion counts only the three outside aces. The Roman Key Card Blackwood version, commonly called Exclusion RKCB, also counts the trump king, so the two methods need different response agreements.
The usual form is a jump to a new suit at the four or five level after a fit is established. That jump announces the void and starts the agreed outside-control response scale.
To stay distinct from splinters and control bids, the Exclusion jump is normally a bid beyond game in the agreed suit. After 1 - 3, for example, 3, 4, and 4 are control bids, while 4, 5, and 5 are Exclusion. Note that a partnership playing Kickback has already assigned that 4 to the key-card ask, so the two conventions collide directly and one of them has to move. Some pairs also allow an unusual jump before any raise, implicitly agreeing partner's last-bid suit, but that needs explicit discussion.
Because the reply often arrives at the five level, the asker needs a hand that can stand even the weakest response.
Spade void with hearts agreed
- 4 is Exclusion Blackwood in many expert methods.
- Hearts are agreed and the asker excludes the spade ace from partner's ace or keycard count.
Diamond void with spades agreed
- 5 shows a diamond void and asks for outside aces or key cards, depending on the method.
- The auction is already high, so both players need firm agreement.
Step responses
Plain Exclusion can use ascending steps for zero, one, two, or three outside aces. Exclusion RKCB instead uses a 0314 or 1430 response map and includes the trump king among the key cards.
In Exclusion RKCB 1430, the first step shows one or four outside key cards, the second zero or three, and later steps two without or with the trump queen. The 0314 version reverses the first two steps.
The difficult part is counting steps correctly. The first available bid after the Exclusion ask is step one, even if that bid is 4NT or a five-level suit bid.
Some partnerships prefer a simpler scale, such as steps for zero, one without the trump queen, one with, two without, and two with, on the logic that partner rarely holds three or four key cards opposite an Exclusion hand.
- Agree whether the partnership counts outside aces only or uses Exclusion RKCB.
- If using Exclusion RKCB, agree whether 1430 or 0314 applies.
- Do not count the ace of the void suit.
- Count the trump king only in the keycard version.
- Use the cheapest non-trump bid for a queen ask only if the agreed structure includes one.
- After the response, a return to the agreed trump suit at the cheapest level is a signoff.
Counting the steps
- 5 is Exclusion with a diamond void and spades agreed.
- Playing Exclusion RKCB 1430, 5 is the first step and shows one or four key cards outside diamonds; playing 0314 the same bid shows zero or three.
Queen ask in Exclusion RKCB
After an Exclusion RKCB response, the asker may need to know about the trump queen. Many pairs use the cheapest non-trump bid as the queen ask. Partner signs off in the trump suit without the queen, bids 5NT with the queen and no side king, or shows a side king by bidding that suit; some pairs instead jump to six of the trump suit with the queen and nothing else to show.
The king of the excluded suit should normally not be shown as a side king. The whole point of Exclusion is that cards in the void suit may have reduced value.
Competition and ambiguity
Exclusion can be dangerous in competitive auctions because a jump in the opponents' suit might also look like a control bid, a splinter, or a natural action. Partnerships must define when Exclusion applies.
If opponents double or bid over the Exclusion ask, response systems such as DOPI, ROPI, or DEPO may be needed. Without an interference agreement, the auction can become unplayable at the five level.
Hand examples
The asker should have a hand where the excluded ace truly does not matter and where knowing outside key cards can decide slam level.
Spade void and heart fit
- After partner raises hearts, this strong six-card heart suit and spade void justify taking control with the agreed Exclusion ask.
- A jump in spades asks for outside aces or key cards while excluding the spade ace; ordinary 4NT would count an ace that is not useful opposite the void.
Answering the Exclusion ask
- After 1 - 3 - 5, this hand counts one key card outside diamonds: the heart ace.
- The diamond king is not counted and is likely wasted opposite the void; the trump queen can still be shown if the asker continues with a queen ask.
Not an Exclusion hand
- This hand has no void.
- Use ordinary keycard tools or control bidding instead.
Common mistakes
- Forgetting to exclude the ace of the void suit.
- Mixing plain outside-ace responses with Exclusion RKCB responses.
- Using Exclusion when trump is not clearly agreed.
- Confusing an Exclusion jump with a splinter or control bid.
- Counting response steps from the wrong starting bid.
- Using Exclusion with a void but no realistic slam interest.
FAQ
Is Exclusion Blackwood the same as Voidwood?
Yes. Voidwood is a common name for Exclusion Blackwood or Exclusion Keycard methods; the original version is credited to the American expert Bobby Goldman.
Does partner count the ace of the void suit?
No. The excluded suit ace is ignored because the asker is void in that suit.