1. To open 1 NT, you need :
12 – 14 pts,
A balanced hand, i.e. one of :
and the 5 card suit must be a minor suit (C or D). If it is a major, open 1 of that suit.
Note : the “opening bid” is the first bid made in the auction.
2. Summary of responses to an opening bid of 1 NT by your partner
This assumes you are not playing transfers or Stayman :
2nd bid by the opener
0 – 10
Only 4 cards
any 5+ suit
2 of suit
11 - 12
3 NT with 14 pts, pass with 12, use judgement with 13
13 - 19
11 – 17
5 card major
3 of suit
3 NT with 2 cards in the suit, else 4 of the suit
6 card major
4 of suit
11 - 17
minor, very unbalanced
3 of suit or even 5 of suit
3 NT with 2 or 3 in the suit, else 4 of the suit
As above. You may then bid again to try for a slam
The aim is to decide if you can make game and if not, to stop the bidding as soon as possible for a part score. If the responder has at least 11 points, then game may be on. With 13+, game is on and you must look for a playable suit, i.e. where you hold 8 cards between you, or if not bid 3NT.
The above are guidelines. You need to use judgement when you have a hand that is borderline or very unbalanced.
3. Opening leads against a NT contract
If your longest suit has a sequence of 3 or more, lead top of the sequence. Otherwise, lead 4th highest. If opponents have bid a suit, try to avoid leading it. If partner made the opening lead, lead back the highest card of the suit led unless you have very few cards in it.
E.g. with K Q J 6 4, lead the K. With Q J 7 6 4, lead the 6 (but in a suit contract lead the Q). When you lead the K, partner knows you have the Q and not the A.