This is usually the last part of the card I fill out with a new partner. It requires lots of work.
The range should be 15-17 - that's the easy part. (In the old days, when opening bids were sounder, 16-18 or even 15 - 18 was in fashion.) Also, I advocate 1NT with a 5-card major and a balanced hand in that range (some teachers espouse otherwise).
Keeping it simple, here are the main issues to discuss:
Everyone uses s 2 to transfer to hearts and 2 for spades.
Everyone also asks me what to do about minors and the responses of 2, 2NT and higher.
Not too important. Just pick something (or even nothing) and agree! I can't say I prefer one method over the other. Each has pluses and minuses. I'd guess the best/most popular treatment today is :
1N-P-2 = transfer to clubs (usually clubs, but possibly a balanced invitational hand)
1N-P-2N = transfer to diamonds
After 1NT-P-2, the opener must bid 2NT with a minimum. If responder had a balanced invitation, he passes 2NT. If he had clubs, he bids 3 if he is weak and wants to play there. If he has clubs GF, he bids something else on the 3-level (if you can remember it, shortness is best -- so 1N-2-any-3// means club suit, GF and shortness in the suit just bid).
After 1NT-P-2, the opener must bid 3 with a maximum. If responder was looking only for min/max, he now goes to 3NT. If he wanted to play in 3, he passes. If he has clubs, GF, he can now bid a new 3-level suit to show shortness.
After 1NT-P-2NT, the opener can bid 3 with a maximum/acceptance and 3 with a minimum/rejection.
These 2 and 2NT transfers free up the 3-level responses. You can use them as splinter bids (each bid shows a 3-suiter with shortness in the suit jumped into). Or, you could choose to use 3 as the transfer to diamonds (or even as Puppet Stayman--asking for a 5-card major). You could also use a different scheme (such as each bid shows 5-5 in the minors or majors with varying strengths). Just pick something (or nothing) and memorize it. No big deal which method you choose.
Also decide if you are using Texas (4-level) transfers. If you can remember them, they are a good idea. That way, you can use Texas to sign-off, while Jacoby followed by a jump to four is a mild slam try. See my article on this topic.
Jumps to 4 are Gerber (ace-asking). Decide what it means if you transfer and bid a new suit. Most people play new suits as natural and game forcing. (You could also decide that a transfer to a minor, followed by a 3-level bid is shortness. This all depends on how you use Stayman. Again, no big deal. Pick something and agree.
B. Stayman Follow-ups
Some of this depends on how you choose to use transfers. The first issue is what it means to bid Stayman and then follow-up on the two-level.
Assuming the transfer scheme above (in A), Stayman then 2NT would be invitational (with or without a 4-card major). Stayman followed by a bid on the 2-level should be NF. (1N-2-2-2 should be pass/correct--a weak hand). 1N-2-2any-2 should be some off-shape invitational hand, typically with 5 spades. This area can get complicated--let's just leave it at this without getting unneeded headaches.
Stayman followed by a 3-level bid in a new minor, should be natural. If you use a transfer to a minor followed by 3-of-a major as natural, forcing, then I suggest you use Stayman, then 3-of-a-minor as weak. (For example, if 1N-2-3-3 was a transfer to clubs followed by natural hearts, then 1N-2-2-3 should be natural, weak). Again, this is a complex area. Don't lose sleep over it, but discuss with your partner if: 1N-2-2MAJ-3-minor is weak, forcing, or maybe even invitational. Pick something and live with it.
Stayman followed by 3-of-the-other major should be an artificial slam try (1N-2-2-3 or 1N-2-2-3). There are fancier possibilities here, but this is sufficient for an intermediate-level partnership.
Discuss what Stayman followed by a jump to 4 is (Gerber or a splinter?)
Do you play Smolen? If so, 1N-2-2-3MAJ = 4-5 (with 4 in the major jumped into).
This discussion of Stayman and Transfers is far from complete. However, I've pointed out most of the major discussion points. If you cover everything here, you'll have 95% of the battle resolved. There is no substitute for a bit of
brain-grinding here -- you can't breeze through this section of the card and expect to
get it all.
These days, the opponents are more likely than ever to interfere. You need some agreements.
If they make a penalty double, agree on what your runouts are (are transfers off?--they should be).
If they make an artificial double, you should ignore it (systems on).
If they overcall with 2, unless it shows majors, I recommend that Double is Stayman, and all other bids mean what they would have meant (transfers, etc.).
If they interfere with 2 or higher, I know it is popular to use a scheme similar to the one above (sometimes called
mirror doubles or
stolen bid.) This isn't practical. It's better to use doubles (of 2 and higher) as
cards -- like a negative double. Other bids should be natural. I recommend playing
Negative Doubles over any natural overcall of 1NT. For more on this (and a discussion of lebensohl), see my article on the subject.
Bottom line on 1NT : There is plenty to discuss. Try to keep it simple, but form agreements on the issues (shown above) that are likely to arise. Use this as a guide for a new partnership--but not for a serious long-term plan. If I were to spend 30 minutes filling out a convention card, I'd devote 10-15 minutes to this section.