[DavidKok]

Here is how I like to play the multi 2♦, and how I like to defend against it.

Multi 2♦ opening
Technically the version I prefer is called the 'Wagner'. It is a weak-only multi, showing a weak two in an undisclosed major. Your length and strength, ODR and other requirements should depend on seating and vulnerability much like a regular weak 2. Over here it is standard that a multi always promises exactly a six card suit. I prefer to allow five card suits with high frequency, so we pre-alerted this fact (though technically it is not a pre-alert). This is a good example of the name of the convention not being sufficient disclosure. Make sure you verify which local regulations apply before deciding which hands to put in the opening.

Below I regularly refer to responder being 'weak'. This means 'less than invitational', and can be up to a 15-count or so! Be aware of this when interpreting the meaning of the calls.

Constructive auctions:

• Pass: To play. Does not promise diamond length, though usually you are expected to have 4+.
  
• 2♥: One of four hand types(!). Opener passes with hearts and pulls to 2♠ with spades. The hand types are:
  • Weak with a desire to play 2♥ or 2♠ depending on partner’s suit.
    
  • Weak with some hearts and a long minor suit (typically 2-3♥6(+)m).
    
  • Invitational(+) in spades but short in hearts.
    
  • Weak with a long heart suit, preferring 3♥ to 2♠ facing spades.
  If opener has spades they pull to 2♠ and now the continuations are:
  • Pass: Weak, fine with either major.
    
  • 2NT: Invitational(+) for spades, short hearts. Play any scheme you prefer for an asking bid over a weak two in spades - I normally play shortage ask, but e.g. Ogust is popular.
    
  • 3♣: To play, long clubs and heart tolerance.
    
  • 3♦: To play, long diamonds and heart tolerance.¹
    
  • 3♥: To play, short spades and long hearts.
• 2♠: One of four hand types(!). Opener passes with spades and bids 2NT (min) or 3♣ (max) with hearts. The hand types are:
  • Weak with short spades and long hearts.
    
  • Weak with some spades and a long minor suit (typically 2-3♠6(+)m).
    
  • Invitational(+) in hearts but short in spades.
    
  • Weak with a long spade suit, preferring 3♠ to 2♥ facing hearts.
  If opener has hearts they pull to 2NT (minimum) or 3♣ (maximum) and now the continuations are:
  • 3♣/pass: To play, long clubs and spade tolerance.
    
  • 3♦: To play, long diamonds and spade tolerance.¹
    
  • 3♥: To play. This shows a hand that has better heart support than spade support, weak only (over 3♣), weak or invitational (over 2NT).
    
  • 3♠: To play, short hearts and long spades.
    
  • 3NT (over 3♣): To play, does not exist over 2NT.
• 2NT: Invitational(+). Asks for strength and suit.². I've presented a popular simple scheme here, but others exist.
  • 3♣: Minimum with hearts.
    
  • 3♦: Minimum with spades.
    
  • 3♥: Maximum with spades.
    
  • 3♠: Maximum with hearts.
• 3♣: Artificial, invitational(+), showing 5(+)♥ by responder. Asks for opener's heart length.
  • 3♦: 0-1 hearts (now 3♥ is to play).
    
  • 3♥: 2 hearts (pass is to play, all other bids are forcing to game).
    
  • 3♠: 3+ hearts, GF, sets trumps.³
• 3♦: Artificial, invitational(+), showing 5(+)♠ by responder. Asks for opener's spade length.
  • 3♥: 0-1 spades (now 3♠ is to play).
    
  • 3♠: 2 spades (pass is to play, all other bids are forcing to game).
    
  • 3NT: 3+ spades, GF, sets trumps.³
• 3♥: At least 3=3 in the majors, NF, pass or correct, may intend to raise spades.
  
• 3♠: At least 3=4 in the majors, NF, pass or correct.
  
• 3NT: To play.
  
• 4♣: Bid one under your suit. Can be weak with both majors. Can be a slam try, implicitly agreeing trumps with a transfer break.
  
• 4♦: Bid your suit, an ‘aces and spaces’ hand. May be a slam try. May be weak.
  
• 4♥: Pass or correct (if you wish to play 4♥ facing spades bid 3♣ or 4♣).
  
• 4♠: To play.

Competitive auctions:
When we open a multi 2♦ and the opponents interfere we want to apply maximum pressure. This is where even world class players tend to have lousy agreements, and you can steal from them with high frequency if you are more prepared. My competitive agreements after partner opens a multi 2♦ are based on a simple set of 8 rules that are relatively easy to remember but still quite effective.
The most frequent interference is going to be a double by them or a 2M overcall. In these scenarios especially we should be completely comfortable with our agreements. Here are my rules for competitive auctions after we open a Wagner 2♦:

• The meaning of responder's 3♥ and higher is always(!) unchanged.
  
• If they bid 2NT or higher, double is penalties.
  
• If they overcall 2♥ through 3♣, our suit bid up to and including 3♦ is natural and NF.
  
• If they overcall 2M, double is ‘stolen bid’/’system on’ (note: this is almost the same as 'takeout'). Opener passes with that major and makes the systemic bid with the other one.
  
• If they double 2♦ in second seat (so 2♦*-(X)-?) responder’s bids are:
  • Pass: Request that opener passes with 3(+) diamonds. With 2(-) diamonds, redouble with spades and bid 2♥ with hearts.
    
  • XX: Bid 2♥, even if you have spades. I will place the contract.⁴
    
  • 2♥ through 3♦: System on.⁵
• If they interfere in fourth seat we play simple stolen bid doubles by opener, so 2♦*-(P)-2/3X-(something); and now
  • X = I was about to bid this 'something'.
    
  • Pass = they have gone past my bid.
    
  • Bids = unchanged.
• Specifically on the auction 2♦*-(P)-P-(X), where we have no regular system, opener always passes. This puts immense pressure on them as responder may have long diamonds, or may be able to play in a major suit.
  
• Specifically on the auctions 2♦*-(P)-P-(something); P-(something)-?, we play the same rules as above regarding double and new bids (as if second or fourth hand overcalled).

Defending against the multi 2♦ opening
The defence I prefer is a relatively simple one. It has some slight gaps and can be exploited, but then again so do all other defences I've seen. It is based on natural bidding and a 'train-the-guns' style double, which the opponents were so kind to grant us by playing an opening that most pairs dare not pass with high frequency.

In second seat:

• Pass: Any weak hand.
  
• X: One of two hand types:
  • 13-15 (semi)balanced with at least 4-3 in the majors either way, at least 2 diamonds and no better bid. Note: the only non-balanced hands that meet these requirements are (43)=5=1 and 4=4=4=1, which you may choose to omit.
    
  • Any hand too strong for a direct bid, e.g. 20+ balanced or ~18+ unbalanced.
  Over this double our next double (either by us or by partner) is takeout, while bidding again shows the strong hand. If the opponents passed or bid 2M over our double we also play Transfer Lebensohl.
• 2♥: 11-17 or so, 5(+)♥. The opponents graciously allowed us to overcall 2♥ over their presumed 2♠ opening, so I am happy to stretch this bid a little at the bottom to take them up on that offer. Over this 2NT shows a strong raise, while all suit bids (including spades) are natural.
  
• 2♠: 12-17 or so, 5(+)♠. Over this 2NT shows a strong raise, while all suit bids (including hearts) are natural.
  
• 2NT: 16-19 balanced, 2NT system on.
  
• 3♣: 12-17 or so, 5(+)♣.
  
• 3♦: 12-17 or so, 5(+)♦.
  
• 3♥: Approximately 13-16 with a good 6(+)♥ suit.
  
• 3♠: Approximately 13-16 with a good 6(+)♠ suit.
  
• 3NT: To play, usually based on a long minor.
  
• 4♣: 5(+)♣5(+)♥, GF.⁶
  
• 4♦: 5(+)♦5(+)♥, GF.⁶
  
• 4♥: To play. Wide ranging.
  
• 4♠: To play. Wide ranging.

Note that a pure takeout type hand of a major suit has to pass initially and hope to give a takeout double on the next round. Some pairs will pass their 2♦ opening (though few as frequently as I do), in which case we pay up. Such a takeout type hand has some diamond length, so it's often not easy for the opponents to find a 'pass'.


In fourth seat:
If they responded 2M we treat that as a 2M opening, using regular takeout doubles of that suit (even though it hasn't been confirmed yet!) and natural bids. The takeout double also activates Transfer Lebensohl. Note that this means that on (2♦*)-P-(2♥*)-2♠ the heart suit is treated as the cue, and if partner were to bid 2NT it would be natural - unlike the scenario where partner overcalled in direct seat!
If they pass their 2♦ we play the same system in fourth seat as we play in second seat. A pure takeout double of a major can be really stuck here and has to pass, but keep in mind that partner would have taken action with that major and some strength - either the opponents are missing a big fit, or we likely don't have the strength to make game.
If they bid 2NT or up the meaning depends on their system, but normally they will announce either strength or an anchor suit and we default to meta-agreements in competition. If they jump respond with a 'pass-or-correct' bid again we treat it as a preemptive opening in the suit bid.


In sixth seat:
On the auctions (2♦*)-P-(2M)-P; (P/2♠)-? a double is takeout of that major. You will almost never do anything except pass or double here, but if you do a 2NT bid shows both minors and a 3m bid shows a weak hand with a long suit, competing for the partscore. Note that, again, the double activates Transfer Lebensohl.



¹With a long diamonds hand and a short major you can also choose to pass 2♦ of course, which is usually better.
²Since 2NT is always invitational(+) (and never 'psyched' with a weak hand), there are better schemes. We can resolve 8 hand types of opener below 3NT, meaning 2x2x2 is a natural choice. For example, hearts/spades, min/max, 5/6 cards (or, if you rarely or never open a Wagner with a five card suit, a different third feature such as suit quality can be shown). This is a little bit more work but you can show three features and stop in 3M opposite a minimum safely.
³Instead of putting all these hands in a single bid you can zoom to show features immediately. One obvious (but, in my opinion, poor) choice is to clarify whether opener has 6oM3M or whether we've hit the huge 11-card fit. However, this scenario is so rare that I think it's actually not a good use of bidding space. Other zooms exist and are more reasonable, if you want to optimise this very rare scenario.
⁴I have also seen agreements where XX demands opener bid the other major. This makes sense to me and is likely an improvement - it applies more pressure in case of a misfit.
⁵Arguably playing 3♣ as 'to play' is better than using it for a strong hand. I do not have this agreement.
⁶The idea is that with 5(+)♠5(+)m we can afford to pass and enter next round, as we won't be shut out of the auction by them preempting to 4♠. This is a remnant of an old multi defence, and I could well do without these bids.

[DavidKok]

In the other thread we talked about 'bunny bashing' a little bit. I think that, on the one hand, it is definitely true that a lot of weaker players struggle to deal with the competitive auctions that you can have after a multi 2♦. On the other hand it is my experience that even world class players can make a mess of these auctions and do not have clear agreements. I do not think it is controversial to say that the multi 2♦ gets some of its profits from opponents being insufficiently prepared - this is true for most competitive gadgets, but I think it is a larger share for the multi than for other conventions. Whether or not you want to call this 'bunny bashing' is to me mostly a matter semantics.

[awm]

This is very similar to what Elianna and I do; there are a few differences in competition (we generally treat new minor bids as forcing, and we invert the redouble and 2M bids after 2♦-X). We use different follow-ups to the 2NT ask, and it's possible we are a bit less free with the five-card preempts than David.

On the "bunny-bashing" topic, it's true that any non-standard method will have a bit of this effect, but in general I don't think playing aggressive preempts is a great strategy against weak players. The issue is that when you lose on these preempts, you're often just too high or you talked opponents out of a badly-breaking contract, and even pretty weak players can capitalise against this. When you win on these preempts, it's typically that you made it harder for opponents to find their best contract, but weak players will often miss their best contract (or misplay it) even if you just pass throughout.

For comparison, I think very weak notrumps are much better for "bunny-bashing" if that's what you're trying to do.

[jillybean]

Thanks David, yet to digest it all but I will, it's a lot.

I think this concept of players using various , less common, conventions to bunny bash should be laid to rest.
For the handful of players who do change their system, psych or whatever against newcomers, let’s deal with them and leave the rest of us playing and disclosing our multi, mini nt in peace.

[jillybean]

Why do you play the weak only version?

[DavidKok]

Good question, and I was debating whether or not to add a (longer) explanation of that to the original post but I decided against it due to the length.

I think weak-only is better than can-be-strong in a lot of ways. Many of these continuations both in and out of competition - my willingness to pass 2♦, my preemptive raises with 3♥ through 4♥ (excepting 3NT), some of the options in the 'pass-or-correct' bids where responder might pull to a new suit later - don't work nearly as well if opener can be strong. Opposite the strong hand we often want to preserve bidding space so that opener can show their hand type, and you very often get 2♥ as a 'default' bid with higher responses having a very specific meaning.
In my opinion, this is terrible. In the can-be-strong version the 2♦ opening is weak something like 90-95% of the time and strong the rest. I hate being behind on my preemptive auctions almost always, to gain a bit of space on the rare strong hands sometimes. Personally I've considered playing my set of continuations on a can-be-strong multi, simply paying up if responder's actions preempt the strong opener - I believe that the pressure auctions are more valuable than the constructive system. However, at that point it is kind of a no-brainer to remove the strong hands.
What's more, strong hands in the multi are not actually good. The bid has a strong self-preemptive effect, frequently starting the description at the 3-level. Opening at the 1-level or with 2♣ gives very similar results, so we're not profiting by putting this in 2♦.
But what really convinced me is the competitive auctions (as always!). Most of my competitive agreements have something in common - responder is in charge, while opener just sticks to the scripted bids. This makes responder captain of the auction and allows for some profitable tactical bids - mind you, all systemic, but still. Many of responder's actions in competition are wide-ranging and not very descriptive. This sort of thing is much more questionable opposite a can-be-strong multi. Again, I've considered just using the same structure and paying up if opener happened to be strong, but at that point I think it's better to remove the liability entirely.

[awm]

It may be worth considering the pluses and minuses of 2♦ multi. Pluses:

1. You free up the 2M openings for something other than weak twos.
2. You right-side some contracts (especially 4M).
3. It's a bit harder to penalise at the two-level (in part because you can try to play in 2♦ or 2♥ when a natural weak two would be higher).

Minuses:

1. Prepared opponents can assign a meaning to a direct pass and then bidding later to show some hand types (i.e. penalty double, minor two-suiter).
2. It's more difficult to raise the preempt, so opponents often face 2♦-pass-2♥-?? instead of say 2♠-Pass-3♠-?? or even 2♠-Pass-4♠-??.
3. Sometimes you're on a guess what to lead on auctions like 2♦-2NT-Pass-3NT, or whether to compete on auctions like 2♦-3m-??.
4. Legality restrictions in North America.

Note that the two biggest minuses (#1 and #2) are made much worse by including a strong option, because now you likely don't want to preempt even with a fit for both majors because opener might have a big balanced hand (or whatever other strong option you include). All you really get in exchange here is to free up the 2NT opening, and I haven't seen any great preemptive use for this yet (most popular is "both minors" which is pretty infrequent and often doesn't work great if partner has the good hand).

[alibodin]

David,

Thank you for posting such a comprehensive article on 2♦ opening being weak in either major. A lot there and my partner and I use and some things I might suggest we consider adding some more. I do like the weak only version as does my partner. I suggested we try and he agreed, and to my surprise he passed my 2♦ opening in MP for a good score, they had 44 fit in 'other' major! It has happened a few times and does seem very effective and score well. Puts a lot of pressure on LHO who cannot pass and wait developments.

[DavidKok]

awm, on 2025-November-10, 04:15, said:

This is very similar to what Elianna and I do; there are a few differences in competition (we generally treat new minor bids as forcing, and we invert the redouble and 2M bids after 2♦-X).

I failed to respond to this, but I think it definitely deserves a reply.

Regarding the nonforcing versus forcing minor bids, I do not have a strong preference. The situation we are talking about is 2♦*-(2M)-? or 2♦*-(3♣)-?, and now we are 'off the hook'. You could argue that new bids should be forcing as weaker misfit hands should not put their head on the chopping block voluntarily. I think we might profit more on balance by competing for the partscore, but it's rarely come up. Either treatment seems fine to me.

Personally I feel more strongly about not inverting the meanings of XX and 2M after 2♦*-(X)-?. Many partnerships play a nebulous double, and rely on responder clarifying their hand to get to a sensible contract. For that reason I want to have a lot of NF bids by responder, applying maximum pressure and forcing my LHO (fourth seat) to commit right away. On balance I think we want to play in opener's suit more often than responder's suit on this start, as opener is known to have a shapely hand while responder may or may not have a shapely hand. By playing 2♥ and 2♠ as 'system on', in particular 'not forcing, I think this is your suit partner, please pass if it is', I think I get to force LHO to commit more often. The situation where I prefer my own suit is lower frequency, and can take the slower (and more exploitable) route of XX.
This comes up frequently, and I think it is worthwhile to squeeze every last bit of advantage out of these auctions.

[steve2005]

Would love to use it. But dont see ACBL allowing it in anything more than it does which is 6+ board matches at imps in some tournaments.

[jillybean]

steve2005, on 2025-November-10, 19:33, said:

Would love to use it. But dont see ACBL allowing it in anything more than it does which is 6+ board matches at imps in some tournaments.

Some clubs allow players to venture outside of the system/convention restrictions.

[DavidKok]

steve2005, on 2025-November-10, 19:33, said:

Would love to use it. But dont see ACBL allowing it in anything more than it does which is 6+ board matches at imps in some tournaments.

My position is close to the opposite - I am allowed to play the Wagner, but prefer not to. I'm afraid I have no influence on the ACBL regulations (though maybe that's for the better).

[mike777]

There is a lot of disagreement on this issue on the ACBL laws committee. Recently Talked with a few of them, Long standing disagreement