Practice on Cuebids
Practice slam auctions where key-card responses, interference, and final-level judgment all matter.
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Systems
Last updated
2026-07-17
What problem do these methods solve?
DOPI, ROPI, and DEPO are methods for answering an ace ask or key-card ask when the next opponent interferes. Without an agreement, responder may not know whether double, pass, or a bid shows key cards, suggests a penalty, or simply gives up on slam.
The methods compress the response scale. They are not glamorous, but they prevent expensive confusion in slam auctions.
Interference over 4NT
- 4NT asked for aces or key cards.
- The opponent's 5 call removes response space.
- Responder needs an agreed structure for double, pass, and available bids.
DOPI and ROPI
DOPI is commonly taught as Double = zero and Pass = one. With key cards, that normally expands to Double = zero or three and Pass = one or four.
Bids over the interference remain available as steps. A common key-card agreement is that the cheapest bid shows two key cards without the trump queen and the next bid two with it; playing plain Blackwood, the cheapest bid simply shows two aces, the next one three, and so on.
ROPI is the related treatment when the opponents double the ask: Redouble = zero or three and Pass = one or four. Because a double consumes no bidding space, responder with exactly two key cards can simply make the normal step response, split by trump-queen status as usual. Three and four are already covered by the redouble and the pass. Partnerships that reverse the first two meanings to preserve a 1430 response order often call the methods DIPO and RIPO instead.
- DOPI is used after an overcall over the ask.
- ROPI is used after a double over the ask.
- In key-card methods, double and pass compress two possible key-card counts into each call.
- Do not assume partner uses the same mapping unless it has been discussed.
DOPI step response
- Spades are agreed as trumps and 4NT is a key-card ask.
- Under standard DOPI, double would show zero or three key cards and pass one or four.
- In a common step agreement, the cheapest bid, 5, shows two key cards without the trump queen; 5 would show two with it.
ROPI after a double
- The double of 4NT is often lead-directing or a suggestion to sacrifice.
- Redouble shows zero or three key cards; pass shows one or four.
- No response space is lost, so bids above 4NT can keep their normal meanings.
DEPO
DEPO is more compressed. Double shows an even number of key cards or aces, and pass shows an odd number. It sacrifices detail to stay lower when the opponents have consumed too much space.
There is no universal DOPI-to-DEPO boundary. One common agreement uses DOPI below five of trumps and DEPO at five of trumps or higher; another uses DOPI when the interference suit ranks below trumps and DEPO when it ranks above. Record the trigger explicitly rather than assuming the boundary.
Compressed high-level response
- If DEPO is agreed, double can show an even number of key cards.
- The partnership gains safety but loses detail about which exact response step responder held.
- The asker may pass the double out for penalties when the answer rules slam out.
Responder with two key cards
- With spades agreed, the king of trumps and the ace of hearts are two key cards.
- Over 6 interference, a DEPO double shows an even number; the asker can usually tell from their own hand whether that means zero or two.
Using response steps
Modern partnerships often think in steps rather than literal aces. If ordinary RKCB uses 1430, the first step means one or four and the second means zero or three. Preserving that order after interference reverses standard DOPI and is commonly labeled DIPO: Double = one or four, Pass = zero or three. The analogous treatment after a double of the ask is RIPO.
This is where many accidents happen. One player remembers DOPI literally while the other silently preserves the 1430 step order. Write down both the name and the actual counts.
Responder with one key card
- The ace of spades is one key card regardless of which suit is trumps, and this hand has no trump king that could add another.
- Standard DOPI shows one or four by passing; DIPO shows one or four by doubling.
Partnership agreements
A useful agreement says more than "DOPI on." It says whether DOPI, ROPI, or DEPO applies after Blackwood, RKCB, Gerber, Kickback, and Minorwood; whether meanings are literal or response-step based; and whether double can ever be penalty.
Common mistakes
- Remembering the acronym but not whether it maps to literal ace counts or response steps.
- Calling the agreement DOPI while one partner is actually using the reversed DIPO mapping.
- Using DOPI at a level where DEPO or pass-out judgment may be safer.
- Forgetting whether the agreement applies after Gerber, Kickback, or Minorwood.
- Doubling for penalty when partner expects a key-card response.
FAQ
What does DOPI mean?
DOPI is commonly remembered as Double = zero or three and Pass = one or four after an opponent overcalls a key-card ask. DIPO reverses those meanings.
What does DEPO mean?
DEPO uses double to show an even number and pass to show an odd number, trading precision for space.
Does DOPI work with Roman Key Card Blackwood?
Yes. Standard DOPI uses double for zero or three and pass for one or four. Partnerships that preserve a 1430 first-step response use the reversed DIPO mapping instead.