[jillybean]

If you play 1♣ 2♣ and 1♦ 2♦ as invitational + what are openers rebids;

[Mbodell]

There are a few different options. One is:

all balanced minimums bid 2nt, nat, nf.
otherwise, bid stoppers up the line and you are in a force through 3m

[Cyberyeti]

Depends whether the opening bids are 4+ cards or 3/2+, weak/strong NT and whether you allow 4M.

I would however recommend 1♣-2♣-2♦ as artificial to leave more space. We actually play 1♦-2♦-2N as the GF ask (in a weak NT context so you either have extra shape or points) but some people use 2♥.

[sfi]

Another option is that an immediate 3m re-raise by opener is the only non-GF continuation. Anything else shows enough extras to accept game opposite an invitational response.

[Siegmund]

Traditional at one time, and still popular in my area, is showing stoppers at the 2-level, with 2NT and 3m by either partner at any time passable. (So if you had 15 but both majors stopped, you better start with 2H and then continue when partner tries to sign off.) 1m-2m-3M usually a GF splinter.

It works best in conjunction with 1m-2NT natural and forcing, since it's a structure designed to handle both inv-vs-GF and stoppers-vs-not.

It works very well for only getting you to 3NT when everything is stopped. But it gets a little frustrating when the field blasts 3NT blindly and makes it on a wrong lead or a 4-4 break in the wide-open suit and your double-dummy-perfect 3C+1 scores about 20%. I am reluctantly considering giving it up if I find a structure I like better.

There are a wide variety of conventional alternatives. Most of them feature just one way for each partner to show a minimum. Some reserve one of opener's rebids for 4441 and another to promise 5m.

[cherdano]

This is an auction where adding some artificial agreements give quite an improvement over standard.
However, I think just playing natural is already an improvement over the stopper-showing-force of standard:
- You are forced to 3m, so 2NT by either partner is natural.
- 2-level suit bids by opener are natural, deny a balanced hand.
- Jumps to a new suit are splinters.
- A jump to 3NT shows the values of 18-19 balanced, with 5-6 trumps. (Alternatively, 3-4 trumps. The other 18-19 balanced hands go via 2NT.)
- If you do have to look for stoppers, you can still do so at the 3-level.
- But if you are balanced opposite balanced with the values for game, just bid 3NT already.

[cherdano]

P.S.: My reply is kind of in the wrong forum - to Novices/Beginners I would just say "2m forces to 3m, bid naturally".

[mycroft]

I play that it's a force to 2NT or 3m, and that only those bids can be made directly by an opener not accepting the invite (in fact, I play that 3m shows 4+ and 2NT fewer (I play this over a 2+ 11-15 1♦ sometimes)).

In my weak NT partnership, the only non-GF call is 3m, but that's because the only hand that isn't 15-opposite-support after limit+ is a overstrength weak 2.

There are advantages to playing 1m-2m GF, and disadvantages (criss-cross is your limit raise, maybe, or don't have a limit raise, or 3m is mixed raise and you have no bad-hand preempt, or...) compared to limit+.

[jillybean]

I play 1m 2m gf and criss cross and have never played 1m 2m inv+ or maybe I have but never discussed the follow ups.
The occasional pick up partner wants to play 1m 2m inv+ so I thought it would be useful to understand the options.

[Zelandakh]

If your new partner is a genuine N/B then I would tend to agree with cherdano's second post. If not, then there is some sense in making an immediate division between balanced and unbalanced hands. One nice method is for the first step (1♣ - 2♣; 2♦ or 1♦ - 2♦; 2♥) to show a balanced hand and for other calls to be unbalanced, using 2NT to show an unbalanced hand with values in the "relay" suit. Jumps are best used as splinters. If either partner bids 3m then they show a minimum. One advantage of this is that Responder often knows immediately whether 5m is in the picture when Opener is balanced and can just bid 3NT without giving away any additional information.

[cherdano]

 jillybean, on 2013-February-11, 22:29, said:

I play 1m 2m gf and criss cross and have never played 1m 2m inv+ or maybe I have but never discussed the follow ups.
The occasional pick up partner wants to play 1m 2m inv+ so I thought it would be useful to understand the options.

Pickup partners will think any new suit is stopper-showing. I wouldn't want to guess whether they think 2NT is forcing, so I would never bid that with the values for game.