[haka9]

I tried to find out in BBO discussion, but I couldn't.

We played teams competition: IMP count. Our system included not so precisely defined Lebensohl. My partner opened 1 NT.
Bidding: 1 NT - 2♣ (=Multi-Landy=Majors) - 3♣ - pass - Is 3♣ forcing or invite or what?

[Zelandakh]

You might find this recent thread an interesting read. When you agree Lebensohl you also have to agree in which situations it is used. It is not uncommon to agree Lebensohl over 2♦, 2♥ and 2♠ overcalls but not over 2♣.

If Lebensohl is on in the given sequence then 3♣ should be forcing (you bid 2NT with a weak hand and clubs). If playing System On then 3♣ is whatever it would have been without the overcall. There are other methods possible here too, of course. In short, the definitive answer to your question is "it depends".

[lowerline]

haka9, on 2013-May-04, 10:02, said:

I tried to find out in BBO discussion, but I couldn't.

We played teams competition: IMP count. Our system included not so precisely defined Lebensohl. My partner opened 1 NT.
Bidding: 1 NT - 2♣ (=Multi-Landy=Majors) - 3♣ - pass - Is 3♣ forcing or invite or what?

Forcing of course. You cannot invite in clubs. If you just wanted to play 3♣, you should have used Lebensohl.

Steven

[Gerben42]

I would play this as invitational with ♣, but I guess if you don't agree when Lebensohl applies and how in such cases, I can see where misunderstanding is coming from.

Forcing hands with ♣ would probably bid either Dbl (with missing stopper) or 3NT with stoppers...

[Wackojack]

I recently had a go at covering all overcall of 1NT situations. This is what I came up with when the overcall is 2♣or 2♦to show the majors:

The overcall shows both majors.

When the overcalls are 2♣ (Landy) and 2♦ (Cappelletti) we can efficiently revert to a natural style of responses. Thus:

2♦ Natural non-forcing over 2♣ (Landy)
2♥♠ Showing a stopper in the major suit bid and looking for partner to bid no trumps with a stopper in the other major.
2NT Natural showing a stopper in both majors
3♣♦ Natural game forcing
3♥♠ Singleton (or void)
3NT To play
Pass→ dbl Take-out showing 4 in the other major
Pass →3♣♦ Weak
Pass→2NT Minors
Dbl It is our hand usually balanced with no stops in the majors at least 4-3 and values in the minors. If LHO bids a major, then double by partner is for take-out into a minor.


So immediate 3♣ is game forcing and pass then 3♣is competitive. Yes if you played 2NT as Lebensohl you could play 2N-3♣ as "to play" and pass then 3♣ as invite. But then you would lose 2NT in its natural sense.

[Gerben42]

lowerline, on 2013-May-06, 07:53, said:

Forcing of course. You cannot invite in clubs. If you just wanted to play 3♣, you should have used Lebensohl.

Steven

This must be the optimal system. The opponents bid 2♣ showing majors, taking up zero space and practically eliminating half our potential contracts, and suddenly I cannot invite in a minor.

My full system here is similar to that after the 2m opening bid showing majors:

1NT (2m = ♥+♠)

Dbl: Points, some values in both majors, future doubles are penalty
2♥: GF with 5+♣
2♠: GF with 5+♦
2NT: Both minors, invite of better
3m: Invitational
3M: GF with Qxx or better and at most singleton in the other major (typically 5431)
3NT: To play

[Vampyr]

The treatments above seem very vulnerable to pschying, and also give up the possibility of playing in a major suit when overcaller might have Jxxx. I think that it is better to allow for finding major suits even after Landy and the like.

[haka9]

Gerben42, on 2013-May-07, 10:32, said:

This must be the optimal system. The opponents bid 2♣ showing majors, taking up zero space and practically eliminating half our potential contracts, and suddenly I cannot invite in a minor.

My full system here is similar to that after the 2m opening bid showing majors:

1NT (2m = ♥+♠)

Dbl: Points, some values in both majors, future doubles are penalty
2♥: GF with 5+♣
2♠: GF with 5+♦
2NT: Both minors, invite of better
3m: Invitational
3M: GF with Qxx or better and at most singleton in the other major (typically 5431)
3NT: To play

Why does DBL show some values in both majors?

[steve2005]

haka9, on 2013-May-09, 13:26, said:

Why does DBL show some values in both majors?

Yes, I think double should be values in one or more majors
that way you can later double a major for penalty and opener might be able to double the other major.
similar methods are used with unusual vs unusual

guess you scramble if nobody can double opponents major