If your partner opens with a suit at one level she is promising up to 19 points. It is therefore important that you respond if you have more than 5 points.
As a general rule your bids should be at the lowest possible level to allow a full bidding conversation with your partner.
If the responder bids a new suit the opener must bid again for one round.
The responders bid provides a lot of information only if it is an accurate. The response varies according to the strength of the hand.
A. < 6 points - Pass
B. 6 to 9 points - You may ONLY bid at the one level, except if you have 4 card support in the openers suit, then you can raise the bid to the two level.
Bid your longest suit at level one if able to do so.
Bid a four card major at level one.
Finding a fit in a major suit is highly desirable.
If your longest suit can only be bid at 2 level then bid 1NT
A RESPONSE OF 1NT PROMISES THE OPENER THAT YOU DO NOT HAVE A FOUR CARD MAJOR THAT COULD BE BID AT LEVEL ONE.
If the opener bids 1S, a holding of hearts can not be shown at level one therefore the responder bids 1NT.
If you have four cards in both majors, bid hearts first to allow your partner to rebid spades at the lowest level.
C. 10 to 12 points
With 4 card support in yours partner’s suit, jump raise i.e. skip a level in the bidding.
If you do not have partner’s suit bid your longest suit at 2 level.
If your have no five card suit, bid the majors first. With 4/4 in hearts and spades bid hearts first.
With no four card major bid 2NT. The exception to this is if your partner opened one spade. A response of 2H promises a 5 card suit. Without a 5 card suit you must bid your next best suit. This is to avoid bidding 2NT which is used in a convention called Jacoby.
A RESPONSE OF 2NT DENIES HAVING A FOUR CARD MAJOR
D. 13 to 14 points
With a 4 card support in your partner's major suit, bid game.
If you can support your partner's minor suit, bid your best major to explore a game contract in 3NT. Controls in the other suits and a good fit in the openers minor makes a good no trump contract.
If you have a flat hand and no four card major bid 3NT.
A RESPONSE OF 3NT DENIES A FOUR CARD MAJOR
E. 15 plus points
Don't jump to game too quickly because there might be the opportunity of winning 12 tricks (a slam) together with the bonus.
Jump bid (skip a level) if you have at least 4 in your partner's suit.
Bid your four card major suits.
Jump bid your five card suits.
If your partner's rebid shows a strong hand you can use Blackwood to explore a slam.
NB. A jump bid in a new suit is game forcing. Bidding must continue until a game contract is found.